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authorsascha <sascha@nomad.localdomain>2007-10-19 11:05:12 +0200
committersascha <sascha@nomad.localdomain>2007-10-19 11:05:12 +0200
commit7e149c897b95b40752d52055af7618f714a44e6b (patch)
tree0f0aea97d0177765c91a05f6f2f10d9cbbd61602 /README
parentceac76ffceca6e5648c6870dd51103169a476e00 (diff)
downloadbarebox-7e149c897b95b40752d52055af7618f714a44e6b.tar.gz
barebox-7e149c897b95b40752d52055af7618f714a44e6b.tar.xz
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-#
-# (C) Copyright 2000 - 2005
-# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
-#
-# See file CREDITS for list of people who contributed to this
-# project.
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License as
-# published by the Free Software Foundation; either version 2 of
-# the License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
-# MA 02111-1307 USA
-#
-
-Summary:
-========
-
-This directory contains the source code for U-Boot, a boot loader for
-Embedded boards based on PowerPC, ARM, MIPS and several other
-processors, which can be installed in a boot ROM and used to
-initialize and test the hardware or to download and run application
-code.
-
-The development of U-Boot is closely related to Linux: some parts of
-the source code originate in the Linux source tree, we have some
-header files in common, and special provision has been made to
-support booting of Linux images.
-
-Some attention has been paid to make this software easily
-configurable and extendable. For instance, all monitor commands are
-implemented with the same call interface, so that it's very easy to
-add new commands. Also, instead of permanently adding rarely used
-code (for instance hardware test utilities) to the monitor, you can
-load and run it dynamically.
-
-
-Status:
-=======
-
-In general, all boards for which a configuration option exists in the
-Makefile have been tested to some extent and can be considered
-"working". In fact, many of them are used in production systems.
-
-In case of problems see the CHANGELOG and CREDITS files to find out
-who contributed the specific port.
-
-
-Where to get help:
-==================
-
-In case you have questions about, problems with or contributions for
-U-Boot you should send a message to the U-Boot mailing list at
-<u-boot-users@lists.sourceforge.net>. There is also an archive of
-previous traffic on the mailing list - please search the archive
-before asking FAQ's. Please see
-http://lists.sourceforge.net/lists/listinfo/u-boot-users/
-
-
-Where we come from:
-===================
-
-- start from 8xxrom sources
-- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
-- clean up code
-- make it easier to add custom boards
-- make it possible to add other [PowerPC] CPUs
-- extend functions, especially:
- * Provide extended interface to Linux boot loader
- * S-Record download
- * network boot
- * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
-- create ARMBoot project (http://sourceforge.net/projects/armboot)
-- add other CPU families (starting with ARM)
-- create U-Boot project (http://sourceforge.net/projects/u-boot)
-
-
-Names and Spelling:
-===================
-
-The "official" name of this project is "Das U-Boot". The spelling
-"U-Boot" shall be used in all written text (documentation, comments
-in source files etc.). Example:
-
- This is the README file for the U-Boot project.
-
-File names etc. shall be based on the string "u-boot". Examples:
-
- include/asm-ppc/u-boot.h
-
- #include <asm/u-boot.h>
-
-Variable names, preprocessor constants etc. shall be either based on
-the string "u_boot" or on "U_BOOT". Example:
-
- U_BOOT_VERSION u_boot_logo
- IH_OS_U_BOOT u_boot_hush_start
-
-
-Versioning:
-===========
-
-U-Boot uses a 3 level version number containing a version, a
-sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
-sub-version "34", and patchlevel "4".
-
-The patchlevel is used to indicate certain stages of development
-between released versions, i. e. officially released versions of
-U-Boot will always have a patchlevel of "0".
-
-
-Directory Hierarchy:
-====================
-
-- board Board dependent files
-- common Misc architecture independent functions
-- cpu CPU specific files
- - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
- - arm720t Files specific to ARM 720 CPUs
- - arm920t Files specific to ARM 920 CPUs
- - at91rm9200 Files specific to Atmel AT91RM9200 CPU
- - imx Files specific to Freescale MC9328 i.MX CPUs
- - s3c24x0 Files specific to Samsung S3C24X0 CPUs
- - arm925t Files specific to ARM 925 CPUs
- - arm926ejs Files specific to ARM 926 CPUs
- - arm1136 Files specific to ARM 1136 CPUs
- - at32ap Files specific to Atmel AVR32 AP CPUs
- - i386 Files specific to i386 CPUs
- - ixp Files specific to Intel XScale IXP CPUs
- - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
- - mips Files specific to MIPS CPUs
- - mpc5xx Files specific to Freescale MPC5xx CPUs
- - mpc5xxx Files specific to Freescale MPC5xxx CPUs
- - mpc8xx Files specific to Freescale MPC8xx CPUs
- - mpc8220 Files specific to Freescale MPC8220 CPUs
- - mpc824x Files specific to Freescale MPC824x CPUs
- - mpc8260 Files specific to Freescale MPC8260 CPUs
- - mpc85xx Files specific to Freescale MPC85xx CPUs
- - nios Files specific to Altera NIOS CPUs
- - nios2 Files specific to Altera Nios-II CPUs
- - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
- - pxa Files specific to Intel XScale PXA CPUs
- - s3c44b0 Files specific to Samsung S3C44B0 CPUs
- - sa1100 Files specific to Intel StrongARM SA1100 CPUs
-- disk Code for disk drive partition handling
-- doc Documentation (don't expect too much)
-- drivers Commonly used device drivers
-- dtt Digital Thermometer and Thermostat drivers
-- examples Example code for standalone applications, etc.
-- include Header Files
-- lib_arm Files generic to ARM architecture
-- lib_avr32 Files generic to AVR32 architecture
-- lib_generic Files generic to all architectures
-- lib_i386 Files generic to i386 architecture
-- lib_m68k Files generic to m68k architecture
-- lib_mips Files generic to MIPS architecture
-- lib_nios Files generic to NIOS architecture
-- lib_ppc Files generic to PowerPC architecture
-- net Networking code
-- post Power On Self Test
-- rtc Real Time Clock drivers
-- tools Tools to build S-Record or U-Boot images, etc.
-
-Software Configuration:
-=======================
-
-Configuration is usually done using C preprocessor defines; the
-rationale behind that is to avoid dead code whenever possible.
-
-There are two classes of configuration variables:
-
-* Configuration _OPTIONS_:
- These are selectable by the user and have names beginning with
- "CONFIG_".
-
-* Configuration _SETTINGS_:
- These depend on the hardware etc. and should not be meddled with if
- you don't know what you're doing; they have names beginning with
- "CFG_".
-
-Later we will add a configuration tool - probably similar to or even
-identical to what's used for the Linux kernel. Right now, we have to
-do the configuration by hand, which means creating some symbolic
-links and editing some configuration files. We use the TQM8xxL boards
-as an example here.
-
-
-Selection of Processor Architecture and Board Type:
----------------------------------------------------
-
-For all supported boards there are ready-to-use default
-configurations available; just type "make <board_name>_config".
-
-Example: For a TQM823L module type:
-
- cd u-boot
- make TQM823L_config
-
-For the Cogent platform, you need to specify the cpu type as well;
-e.g. "make cogent_mpc8xx_config". And also configure the cogent
-directory according to the instructions in cogent/README.
-
-
-Configuration Options:
-----------------------
-
-Configuration depends on the combination of board and CPU type; all
-such information is kept in a configuration file
-"include/configs/<board_name>.h".
-
-Example: For a TQM823L module, all configuration settings are in
-"include/configs/TQM823L.h".
-
-
-Many of the options are named exactly as the corresponding Linux
-kernel configuration options. The intention is to make it easier to
-build a config tool - later.
-
-
-The following options need to be configured:
-
-- CPU Type: Define exactly one of
-
- PowerPC based CPUs:
- -------------------
- CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
- or CONFIG_MPC5xx
- or CONFIG_MPC8220
- or CONFIG_MPC824X, CONFIG_MPC8260
- or CONFIG_MPC85xx
- or CONFIG_IOP480
- or CONFIG_405GP
- or CONFIG_405EP
- or CONFIG_440
- or CONFIG_MPC74xx
- or CONFIG_750FX
-
- ARM based CPUs:
- ---------------
- CONFIG_SA1110
- CONFIG_ARM7
- CONFIG_PXA250
- CONFIG_CPU_MONAHANS
-
- MicroBlaze based CPUs:
- ----------------------
- CONFIG_MICROBLAZE
-
- Nios-2 based CPUs:
- ----------------------
- CONFIG_NIOS2
-
- AVR32 based CPUs:
- ----------------------
- CONFIG_AT32AP
-
-- Board Type: Define exactly one of
-
- PowerPC based boards:
- ---------------------
-
- CONFIG_ADCIOP CONFIG_FPS860L CONFIG_OXC
- CONFIG_ADS860 CONFIG_GEN860T CONFIG_PCI405
- CONFIG_AMX860 CONFIG_GENIETV CONFIG_PCIPPC2
- CONFIG_AP1000 CONFIG_GTH CONFIG_PCIPPC6
- CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e
- CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405
- CONFIG_BC3450 CONFIG_hymod CONFIG_PM826
- CONFIG_c2mon CONFIG_IAD210 CONFIG_ppmc8260
- CONFIG_CANBT CONFIG_ICU862 CONFIG_QS823
- CONFIG_CCM CONFIG_IP860 CONFIG_QS850
- CONFIG_CMI CONFIG_IPHASE4539 CONFIG_QS860T
- CONFIG_cogent_mpc8260 CONFIG_IVML24 CONFIG_RBC823
- CONFIG_cogent_mpc8xx CONFIG_IVML24_128 CONFIG_RPXClassic
- CONFIG_CPCI405 CONFIG_IVML24_256 CONFIG_RPXlite
- CONFIG_CPCI4052 CONFIG_IVMS8 CONFIG_RPXsuper
- CONFIG_CPCIISER4 CONFIG_IVMS8_128 CONFIG_rsdproto
- CONFIG_CPU86 CONFIG_IVMS8_256 CONFIG_sacsng
- CONFIG_CRAYL1 CONFIG_JSE CONFIG_Sandpoint8240
- CONFIG_CSB272 CONFIG_LANTEC CONFIG_Sandpoint8245
- CONFIG_CU824 CONFIG_LITE5200B CONFIG_sbc8260
- CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8560
- CONFIG_DB64360 CONFIG_MBX CONFIG_SM850
- CONFIG_DB64460 CONFIG_MBX860T CONFIG_SPD823TS
- CONFIG_DU405 CONFIG_MHPC CONFIG_STXGP3
- CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_SXNI855T
- CONFIG_EBONY CONFIG_MOUSSE CONFIG_TQM823L
- CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM8260
- CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM850L
- CONFIG_ep8260 CONFIG_MPC8540EVAL CONFIG_TQM855L
- CONFIG_ERIC CONFIG_MPC8560ADS CONFIG_TQM860L
- CONFIG_ESTEEM192E CONFIG_MUSENKI CONFIG_TTTech
- CONFIG_ETX094 CONFIG_MVS1 CONFIG_UTX8245
- CONFIG_EVB64260 CONFIG_NETPHONE CONFIG_V37
- CONFIG_FADS823 CONFIG_NETTA CONFIG_W7OLMC
- CONFIG_FADS850SAR CONFIG_NETVIA CONFIG_W7OLMG
- CONFIG_FADS860T CONFIG_NX823 CONFIG_WALNUT
- CONFIG_FLAGADM CONFIG_OCRTC CONFIG_ZPC1900
- CONFIG_FPS850L CONFIG_ORSG CONFIG_ZUMA
-
- ARM based boards:
- -----------------
-
- CONFIG_ARMADILLO, CONFIG_AT91RM9200DK, CONFIG_CERF250,
- CONFIG_CSB637, CONFIG_DELTA, CONFIG_DNP1110,
- CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE,
- CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
- CONFIG_KB9202, CONFIG_LART, CONFIG_LPD7A400,
- CONFIG_LUBBOCK, CONFIG_OSK_OMAP5912, CONFIG_OMAP2420H4,
- CONFIG_PLEB2, CONFIG_SHANNON, CONFIG_P2_OMAP730,
- CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB,
- CONFIG_VCMA9
-
- MicroBlaze based boards:
- ------------------------
-
- CONFIG_SUZAKU
-
- Nios-2 based boards:
- ------------------------
-
- CONFIG_PCI5441 CONFIG_PK1C20
- CONFIG_EP1C20 CONFIG_EP1S10 CONFIG_EP1S40
-
- AVR32 based boards:
- -------------------
-
- CONFIG_ATSTK1000
-
-- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
- Define exactly one of
- CONFIG_ATSTK1002
-
-
-- CPU Module Type: (if CONFIG_COGENT is defined)
- Define exactly one of
- CONFIG_CMA286_60_OLD
---- FIXME --- not tested yet:
- CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
- CONFIG_CMA287_23, CONFIG_CMA287_50
-
-- Motherboard Type: (if CONFIG_COGENT is defined)
- Define exactly one of
- CONFIG_CMA101, CONFIG_CMA102
-
-- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
- Define one or more of
- CONFIG_CMA302
-
-- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
- Define one or more of
- CONFIG_LCD_HEARTBEAT - update a character position on
- the lcd display every second with
- a "rotator" |\-/|\-/
-
-- Board flavour: (if CONFIG_MPC8260ADS is defined)
- CONFIG_ADSTYPE
- Possible values are:
- CFG_8260ADS - original MPC8260ADS
- CFG_8266ADS - MPC8266ADS
- CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
- CFG_8272ADS - MPC8272ADS
-
-- MPC824X Family Member (if CONFIG_MPC824X is defined)
- Define exactly one of
- CONFIG_MPC8240, CONFIG_MPC8245
-
-- 8xx CPU Options: (if using an MPC8xx cpu)
- CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
- get_gclk_freq() cannot work
- e.g. if there is no 32KHz
- reference PIT/RTC clock
- CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
- or XTAL/EXTAL)
-
-- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
- CFG_8xx_CPUCLK_MIN
- CFG_8xx_CPUCLK_MAX
- CONFIG_8xx_CPUCLK_DEFAULT
- See doc/README.MPC866
-
- CFG_MEASURE_CPUCLK
-
- Define this to measure the actual CPU clock instead
- of relying on the correctness of the configured
- values. Mostly useful for board bringup to make sure
- the PLL is locked at the intended frequency. Note
- that this requires a (stable) reference clock (32 kHz
- RTC clock or CFG_8XX_XIN)
-
-- Intel Monahans options:
- CFG_MONAHANS_RUN_MODE_OSC_RATIO
-
- Defines the Monahans run mode to oscillator
- ratio. Valid values are 8, 16, 24, 31. The core
- frequency is this value multiplied by 13 MHz.
-
- CFG_MONAHANS_TURBO_RUN_MODE_RATIO
-
- Defines the Monahans turbo mode to oscillator
- ratio. Valid values are 1 (default if undefined) and
- 2. The core frequency as calculated above is multiplied
- by this value.
-
-- Linux Kernel Interface:
- CONFIG_CLOCKS_IN_MHZ
-
- U-Boot stores all clock information in Hz
- internally. For binary compatibility with older Linux
- kernels (which expect the clocks passed in the
- bd_info data to be in MHz) the environment variable
- "clocks_in_mhz" can be defined so that U-Boot
- converts clock data to MHZ before passing it to the
- Linux kernel.
- When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
- "clocks_in_mhz=1" is automatically included in the
- default environment.
-
- CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
-
- When transfering memsize parameter to linux, some versions
- expect it to be in bytes, others in MB.
- Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
-
- CONFIG_OF_FLAT_TREE
-
- New kernel versions are expecting firmware settings to be
- passed using flat open firmware trees.
- The environment variable "disable_of", when set, disables this
- functionality.
-
- CONFIG_OF_FLAT_TREE_MAX_SIZE
-
- The maximum size of the constructed OF tree.
-
- OF_CPU - The proper name of the cpus node.
- OF_SOC - The proper name of the soc node.
- OF_TBCLK - The timebase frequency.
- OF_STDOUT_PATH - The path to the console device
-
- CONFIG_OF_HAS_BD_T
-
- The resulting flat device tree will have a copy of the bd_t.
- Space should be pre-allocated in the dts for the bd_t.
-
- CONFIG_OF_HAS_UBOOT_ENV
-
- The resulting flat device tree will have a copy of u-boot's
- environment variables
-
- CONFIG_OF_BOARD_SETUP
-
- Board code has addition modification that it wants to make
- to the flat device tree before handing it off to the kernel
-
- CONFIG_OF_BOOT_CPU
-
- This define fills in the correct boot cpu in the boot
- param header, the default value is zero if undefined.
-
-- Serial Ports:
- CFG_PL010_SERIAL
-
- Define this if you want support for Amba PrimeCell PL010 UARTs.
-
- CFG_PL011_SERIAL
-
- Define this if you want support for Amba PrimeCell PL011 UARTs.
-
- CONFIG_PL011_CLOCK
-
- If you have Amba PrimeCell PL011 UARTs, set this variable to
- the clock speed of the UARTs.
-
- CONFIG_PL01x_PORTS
-
- If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
- define this to a list of base addresses for each (supported)
- port. See e.g. include/configs/versatile.h
-
-
-- Console Interface:
- Depending on board, define exactly one serial port
- (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
- CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
- console by defining CONFIG_8xx_CONS_NONE
-
- Note: if CONFIG_8xx_CONS_NONE is defined, the serial
- port routines must be defined elsewhere
- (i.e. serial_init(), serial_getc(), ...)
-
- CONFIG_CFB_CONSOLE
- Enables console device for a color framebuffer. Needs following
- defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
- VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
- (default big endian)
- VIDEO_HW_RECTFILL graphic chip supports
- rectangle fill
- (cf. smiLynxEM)
- VIDEO_HW_BITBLT graphic chip supports
- bit-blit (cf. smiLynxEM)
- VIDEO_VISIBLE_COLS visible pixel columns
- (cols=pitch)
- VIDEO_VISIBLE_ROWS visible pixel rows
- VIDEO_PIXEL_SIZE bytes per pixel
- VIDEO_DATA_FORMAT graphic data format
- (0-5, cf. cfb_console.c)
- VIDEO_FB_ADRS framebuffer address
- VIDEO_KBD_INIT_FCT keyboard int fct
- (i.e. i8042_kbd_init())
- VIDEO_TSTC_FCT test char fct
- (i.e. i8042_tstc)
- VIDEO_GETC_FCT get char fct
- (i.e. i8042_getc)
- CONFIG_CONSOLE_CURSOR cursor drawing on/off
- (requires blink timer
- cf. i8042.c)
- CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
- CONFIG_CONSOLE_TIME display time/date info in
- upper right corner
- (requires CFG_CMD_DATE)
- CONFIG_VIDEO_LOGO display Linux logo in
- upper left corner
- CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
- linux_logo.h for logo.
- Requires CONFIG_VIDEO_LOGO
- CONFIG_CONSOLE_EXTRA_INFO
- addional board info beside
- the logo
-
- When CONFIG_CFB_CONSOLE is defined, video console is
- default i/o. Serial console can be forced with
- environment 'console=serial'.
-
- When CONFIG_SILENT_CONSOLE is defined, all console
- messages (by U-Boot and Linux!) can be silenced with
- the "silent" environment variable. See
- doc/README.silent for more information.
-
-- Console Baudrate:
- CONFIG_BAUDRATE - in bps
- Select one of the baudrates listed in
- CFG_BAUDRATE_TABLE, see below.
- CFG_BRGCLK_PRESCALE, baudrate prescale
-
-- Interrupt driven serial port input:
- CONFIG_SERIAL_SOFTWARE_FIFO
-
- PPC405GP only.
- Use an interrupt handler for receiving data on the
- serial port. It also enables using hardware handshake
- (RTS/CTS) and UART's built-in FIFO. Set the number of
- bytes the interrupt driven input buffer should have.
-
- Leave undefined to disable this feature, including
- disable the buffer and hardware handshake.
-
-- Console UART Number:
- CONFIG_UART1_CONSOLE
-
- AMCC PPC4xx only.
- If defined internal UART1 (and not UART0) is used
- as default U-Boot console.
-
-- Boot Delay: CONFIG_BOOTDELAY - in seconds
- Delay before automatically booting the default image;
- set to -1 to disable autoboot.
-
- See doc/README.autoboot for these options that
- work with CONFIG_BOOTDELAY. None are required.
- CONFIG_BOOT_RETRY_TIME
- CONFIG_BOOT_RETRY_MIN
- CONFIG_AUTOBOOT_KEYED
- CONFIG_AUTOBOOT_PROMPT
- CONFIG_AUTOBOOT_DELAY_STR
- CONFIG_AUTOBOOT_STOP_STR
- CONFIG_AUTOBOOT_DELAY_STR2
- CONFIG_AUTOBOOT_STOP_STR2
- CONFIG_ZERO_BOOTDELAY_CHECK
- CONFIG_RESET_TO_RETRY
-
-- Autoboot Command:
- CONFIG_BOOTCOMMAND
- Only needed when CONFIG_BOOTDELAY is enabled;
- define a command string that is automatically executed
- when no character is read on the console interface
- within "Boot Delay" after reset.
-
- CONFIG_BOOTARGS
- This can be used to pass arguments to the bootm
- command. The value of CONFIG_BOOTARGS goes into the
- environment value "bootargs".
-
- CONFIG_RAMBOOT and CONFIG_NFSBOOT
- The value of these goes into the environment as
- "ramboot" and "nfsboot" respectively, and can be used
- as a convenience, when switching between booting from
- ram and nfs.
-
-- Pre-Boot Commands:
- CONFIG_PREBOOT
-
- When this option is #defined, the existence of the
- environment variable "preboot" will be checked
- immediately before starting the CONFIG_BOOTDELAY
- countdown and/or running the auto-boot command resp.
- entering interactive mode.
-
- This feature is especially useful when "preboot" is
- automatically generated or modified. For an example
- see the LWMON board specific code: here "preboot" is
- modified when the user holds down a certain
- combination of keys on the (special) keyboard when
- booting the systems
-
-- Serial Download Echo Mode:
- CONFIG_LOADS_ECHO
- If defined to 1, all characters received during a
- serial download (using the "loads" command) are
- echoed back. This might be needed by some terminal
- emulations (like "cu"), but may as well just take
- time on others. This setting #define's the initial
- value of the "loads_echo" environment variable.
-
-- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
- CONFIG_KGDB_BAUDRATE
- Select one of the baudrates listed in
- CFG_BAUDRATE_TABLE, see below.
-
-- Monitor Functions:
- CONFIG_COMMANDS
- Most monitor functions can be selected (or
- de-selected) by adjusting the definition of
- CONFIG_COMMANDS; to select individual functions,
- #define CONFIG_COMMANDS by "OR"ing any of the
- following values:
-
- #define enables commands:
- -------------------------
- CFG_CMD_ASKENV * ask for env variable
- CFG_CMD_AUTOSCRIPT Autoscript Support
- CFG_CMD_BDI bdinfo
- CFG_CMD_BEDBUG * Include BedBug Debugger
- CFG_CMD_BMP * BMP support
- CFG_CMD_BSP * Board specific commands
- CFG_CMD_BOOTD bootd
- CFG_CMD_CACHE * icache, dcache
- CFG_CMD_CONSOLE coninfo
- CFG_CMD_DATE * support for RTC, date/time...
- CFG_CMD_DHCP * DHCP support
- CFG_CMD_DIAG * Diagnostics
- CFG_CMD_DOC * Disk-On-Chip Support
- CFG_CMD_DTT * Digital Therm and Thermostat
- CFG_CMD_ECHO echo arguments
- CFG_CMD_EEPROM * EEPROM read/write support
- CFG_CMD_ELF * bootelf, bootvx
- CFG_CMD_ENV saveenv
- CFG_CMD_FDC * Floppy Disk Support
- CFG_CMD_FAT * FAT partition support
- CFG_CMD_FDOS * Dos diskette Support
- CFG_CMD_FLASH flinfo, erase, protect
- CFG_CMD_FPGA FPGA device initialization support
- CFG_CMD_HWFLOW * RTS/CTS hw flow control
- CFG_CMD_I2C * I2C serial bus support
- CFG_CMD_IDE * IDE harddisk support
- CFG_CMD_IMI iminfo
- CFG_CMD_IMLS List all found images
- CFG_CMD_IMMAP * IMMR dump support
- CFG_CMD_IRQ * irqinfo
- CFG_CMD_ITEST Integer/string test of 2 values
- CFG_CMD_JFFS2 * JFFS2 Support
- CFG_CMD_KGDB * kgdb
- CFG_CMD_LOADB loadb
- CFG_CMD_LOADS loads
- CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
- loop, loopw, mtest
- CFG_CMD_MISC Misc functions like sleep etc
- CFG_CMD_MMC * MMC memory mapped support
- CFG_CMD_MII * MII utility commands
- CFG_CMD_NAND * NAND support
- CFG_CMD_NET bootp, tftpboot, rarpboot
- CFG_CMD_PCI * pciinfo
- CFG_CMD_PCMCIA * PCMCIA support
- CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
- CFG_CMD_PORTIO * Port I/O
- CFG_CMD_REGINFO * Register dump
- CFG_CMD_RUN run command in env variable
- CFG_CMD_SAVES * save S record dump
- CFG_CMD_SCSI * SCSI Support
- CFG_CMD_SDRAM * print SDRAM configuration information
- (requires CFG_CMD_I2C)
- CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
- CFG_CMD_SPI * SPI serial bus support
- CFG_CMD_USB * USB support
- CFG_CMD_VFD * VFD support (TRAB)
- CFG_CMD_BSP * Board SPecific functions
- CFG_CMD_CDP * Cisco Discover Protocol support
- -----------------------------------------------
- CFG_CMD_ALL all
-
- CONFIG_CMD_DFL Default configuration; at the moment
- this is includes all commands, except
- the ones marked with "*" in the list
- above.
-
- If you don't define CONFIG_COMMANDS it defaults to
- CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can
- override the default settings in the respective
- include file.
-
- EXAMPLE: If you want all functions except of network
- support you can write:
-
- #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
-
-
- Note: Don't enable the "icache" and "dcache" commands
- (configuration option CFG_CMD_CACHE) unless you know
- what you (and your U-Boot users) are doing. Data
- cache cannot be enabled on systems like the 8xx or
- 8260 (where accesses to the IMMR region must be
- uncached), and it cannot be disabled on all other
- systems where we (mis-) use the data cache to hold an
- initial stack and some data.
-
-
- XXX - this list needs to get updated!
-
-- Watchdog:
- CONFIG_WATCHDOG
- If this variable is defined, it enables watchdog
- support. There must be support in the platform specific
- code for a watchdog. For the 8xx and 8260 CPUs, the
- SIU Watchdog feature is enabled in the SYPCR
- register.
-
-- U-Boot Version:
- CONFIG_VERSION_VARIABLE
- If this variable is defined, an environment variable
- named "ver" is created by U-Boot showing the U-Boot
- version as printed by the "version" command.
- This variable is readonly.
-
-- Real-Time Clock:
-
- When CFG_CMD_DATE is selected, the type of the RTC
- has to be selected, too. Define exactly one of the
- following options:
-
- CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
- CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
- CONFIG_RTC_MC146818 - use MC146818 RTC
- CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
- CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
- CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
- CONFIG_RTC_DS164x - use Dallas DS164x RTC
- CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
-
- Note that if the RTC uses I2C, then the I2C interface
- must also be configured. See I2C Support, below.
-
-- Timestamp Support:
-
- When CONFIG_TIMESTAMP is selected, the timestamp
- (date and time) of an image is printed by image
- commands like bootm or iminfo. This option is
- automatically enabled when you select CFG_CMD_DATE .
-
-- Partition Support:
- CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
- and/or CONFIG_ISO_PARTITION
-
- If IDE or SCSI support is enabled (CFG_CMD_IDE or
- CFG_CMD_SCSI) you must configure support for at least
- one partition type as well.
-
-- IDE Reset method:
- CONFIG_IDE_RESET_ROUTINE - this is defined in several
- board configurations files but used nowhere!
-
- CONFIG_IDE_RESET - is this is defined, IDE Reset will
- be performed by calling the function
- ide_set_reset(int reset)
- which has to be defined in a board specific file
-
-- ATAPI Support:
- CONFIG_ATAPI
-
- Set this to enable ATAPI support.
-
-- LBA48 Support
- CONFIG_LBA48
-
- Set this to enable support for disks larger than 137GB
- Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
- Whithout these , LBA48 support uses 32bit variables and will 'only'
- support disks up to 2.1TB.
-
- CFG_64BIT_LBA:
- When enabled, makes the IDE subsystem use 64bit sector addresses.
- Default is 32bit.
-
-- SCSI Support:
- At the moment only there is only support for the
- SYM53C8XX SCSI controller; define
- CONFIG_SCSI_SYM53C8XX to enable it.
-
- CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
- CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
- CFG_SCSI_MAX_LUN] can be adjusted to define the
- maximum numbers of LUNs, SCSI ID's and target
- devices.
- CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
-
-- NETWORK Support (PCI):
- CONFIG_E1000
- Support for Intel 8254x gigabit chips.
-
- CONFIG_EEPRO100
- Support for Intel 82557/82559/82559ER chips.
- Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
- write routine for first time initialisation.
-
- CONFIG_TULIP
- Support for Digital 2114x chips.
- Optional CONFIG_TULIP_SELECT_MEDIA for board specific
- modem chip initialisation (KS8761/QS6611).
-
- CONFIG_NATSEMI
- Support for National dp83815 chips.
-
- CONFIG_NS8382X
- Support for National dp8382[01] gigabit chips.
-
-- NETWORK Support (other):
-
- CONFIG_DRIVER_LAN91C96
- Support for SMSC's LAN91C96 chips.
-
- CONFIG_LAN91C96_BASE
- Define this to hold the physical address
- of the LAN91C96's I/O space
-
- CONFIG_LAN91C96_USE_32_BIT
- Define this to enable 32 bit addressing
-
- CONFIG_DRIVER_SMC91111
- Support for SMSC's LAN91C111 chip
-
- CONFIG_SMC91111_BASE
- Define this to hold the physical address
- of the device (I/O space)
-
- CONFIG_SMC_USE_32_BIT
- Define this if data bus is 32 bits
-
- CONFIG_SMC_USE_IOFUNCS
- Define this to use i/o functions instead of macros
- (some hardware wont work with macros)
-
-- USB Support:
- At the moment only the UHCI host controller is
- supported (PIP405, MIP405, MPC5200); define
- CONFIG_USB_UHCI to enable it.
- define CONFIG_USB_KEYBOARD to enable the USB Keyboard
- and define CONFIG_USB_STORAGE to enable the USB
- storage devices.
- Note:
- Supported are USB Keyboards and USB Floppy drives
- (TEAC FD-05PUB).
- MPC5200 USB requires additional defines:
- CONFIG_USB_CLOCK
- for 528 MHz Clock: 0x0001bbbb
- CONFIG_USB_CONFIG
- for differential drivers: 0x00001000
- for single ended drivers: 0x00005000
-
-
-- MMC Support:
- The MMC controller on the Intel PXA is supported. To
- enable this define CONFIG_MMC. The MMC can be
- accessed from the boot prompt by mapping the device
- to physical memory similar to flash. Command line is
- enabled with CFG_CMD_MMC. The MMC driver also works with
- the FAT fs. This is enabled with CFG_CMD_FAT.
-
-- Journaling Flash filesystem support:
- CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
- CONFIG_JFFS2_NAND_DEV
- Define these for a default partition on a NAND device
-
- CFG_JFFS2_FIRST_SECTOR,
- CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
- Define these for a default partition on a NOR device
-
- CFG_JFFS_CUSTOM_PART
- Define this to create an own partition. You have to provide a
- function struct part_info* jffs2_part_info(int part_num)
-
- If you define only one JFFS2 partition you may also want to
- #define CFG_JFFS_SINGLE_PART 1
- to disable the command chpart. This is the default when you
- have not defined a custom partition
-
-- Keyboard Support:
- CONFIG_ISA_KEYBOARD
-
- Define this to enable standard (PC-Style) keyboard
- support
-
- CONFIG_I8042_KBD
- Standard PC keyboard driver with US (is default) and
- GERMAN key layout (switch via environment 'keymap=de') support.
- Export function i8042_kbd_init, i8042_tstc and i8042_getc
- for cfb_console. Supports cursor blinking.
-
-- Video support:
- CONFIG_VIDEO
-
- Define this to enable video support (for output to
- video).
-
- CONFIG_VIDEO_CT69000
-
- Enable Chips & Technologies 69000 Video chip
-
- CONFIG_VIDEO_SMI_LYNXEM
- Enable Silicon Motion SMI 712/710/810 Video chip. The
- video output is selected via environment 'videoout'
- (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
- assumed.
-
- For the CT69000 and SMI_LYNXEM drivers, videomode is
- selected via environment 'videomode'. Two diferent ways
- are possible:
- - "videomode=num" 'num' is a standard LiLo mode numbers.
- Following standard modes are supported (* is default):
-
- Colors 640x480 800x600 1024x768 1152x864 1280x1024
- -------------+---------------------------------------------
- 8 bits | 0x301* 0x303 0x305 0x161 0x307
- 15 bits | 0x310 0x313 0x316 0x162 0x319
- 16 bits | 0x311 0x314 0x317 0x163 0x31A
- 24 bits | 0x312 0x315 0x318 ? 0x31B
- -------------+---------------------------------------------
- (i.e. setenv videomode 317; saveenv; reset;)
-
- - "videomode=bootargs" all the video parameters are parsed
- from the bootargs. (See drivers/videomodes.c)
-
-
- CONFIG_VIDEO_SED13806
- Enable Epson SED13806 driver. This driver supports 8bpp
- and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
- or CONFIG_VIDEO_SED13806_16BPP
-
-- Keyboard Support:
- CONFIG_KEYBOARD
-
- Define this to enable a custom keyboard support.
- This simply calls drv_keyboard_init() which must be
- defined in your board-specific files.
- The only board using this so far is RBC823.
-
-- LCD Support: CONFIG_LCD
-
- Define this to enable LCD support (for output to LCD
- display); also select one of the supported displays
- by defining one of these:
-
- CONFIG_NEC_NL6448AC33:
-
- NEC NL6448AC33-18. Active, color, single scan.
-
- CONFIG_NEC_NL6448BC20
-
- NEC NL6448BC20-08. 6.5", 640x480.
- Active, color, single scan.
-
- CONFIG_NEC_NL6448BC33_54
-
- NEC NL6448BC33-54. 10.4", 640x480.
- Active, color, single scan.
-
- CONFIG_SHARP_16x9
-
- Sharp 320x240. Active, color, single scan.
- It isn't 16x9, and I am not sure what it is.
-
- CONFIG_SHARP_LQ64D341
-
- Sharp LQ64D341 display, 640x480.
- Active, color, single scan.
-
- CONFIG_HLD1045
-
- HLD1045 display, 640x480.
- Active, color, single scan.
-
- CONFIG_OPTREX_BW
-
- Optrex CBL50840-2 NF-FW 99 22 M5
- or
- Hitachi LMG6912RPFC-00T
- or
- Hitachi SP14Q002
-
- 320x240. Black & white.
-
- Normally display is black on white background; define
- CFG_WHITE_ON_BLACK to get it inverted.
-
-- Splash Screen Support: CONFIG_SPLASH_SCREEN
-
- If this option is set, the environment is checked for
- a variable "splashimage". If found, the usual display
- of logo, copyright and system information on the LCD
- is suppressed and the BMP image at the address
- specified in "splashimage" is loaded instead. The
- console is redirected to the "nulldev", too. This
- allows for a "silent" boot where a splash screen is
- loaded very quickly after power-on.
-
-- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
-
- If this option is set, additionally to standard BMP
- images, gzipped BMP images can be displayed via the
- splashscreen support or the bmp command.
-
-- Compression support:
- CONFIG_BZIP2
-
- If this option is set, support for bzip2 compressed
- images is included. If not, only uncompressed and gzip
- compressed images are supported.
-
- NOTE: the bzip2 algorithm requires a lot of RAM, so
- the malloc area (as defined by CFG_MALLOC_LEN) should
- be at least 4MB.
-
-- MII/PHY support:
- CONFIG_PHY_ADDR
-
- The address of PHY on MII bus.
-
- CONFIG_PHY_CLOCK_FREQ (ppc4xx)
-
- The clock frequency of the MII bus
-
- CONFIG_PHY_GIGE
-
- If this option is set, support for speed/duplex
- detection of Gigabit PHY is included.
-
- CONFIG_PHY_RESET_DELAY
-
- Some PHY like Intel LXT971A need extra delay after
- reset before any MII register access is possible.
- For such PHY, set this option to the usec delay
- required. (minimum 300usec for LXT971A)
-
- CONFIG_PHY_CMD_DELAY (ppc4xx)
-
- Some PHY like Intel LXT971A need extra delay after
- command issued before MII status register can be read
-
-- Ethernet address:
- CONFIG_ETHADDR
- CONFIG_ETH2ADDR
- CONFIG_ETH3ADDR
-
- Define a default value for ethernet address to use
- for the respective ethernet interface, in case this
- is not determined automatically.
-
-- IP address:
- CONFIG_IPADDR
-
- Define a default value for the IP address to use for
- the default ethernet interface, in case this is not
- determined through e.g. bootp.
-
-- Server IP address:
- CONFIG_SERVERIP
-
- Defines a default value for theIP address of a TFTP
- server to contact when using the "tftboot" command.
-
-- BOOTP Recovery Mode:
- CONFIG_BOOTP_RANDOM_DELAY
-
- If you have many targets in a network that try to
- boot using BOOTP, you may want to avoid that all
- systems send out BOOTP requests at precisely the same
- moment (which would happen for instance at recovery
- from a power failure, when all systems will try to
- boot, thus flooding the BOOTP server. Defining
- CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
- inserted before sending out BOOTP requests. The
- following delays are insterted then:
-
- 1st BOOTP request: delay 0 ... 1 sec
- 2nd BOOTP request: delay 0 ... 2 sec
- 3rd BOOTP request: delay 0 ... 4 sec
- 4th and following
- BOOTP requests: delay 0 ... 8 sec
-
-- DHCP Advanced Options:
- CONFIG_BOOTP_MASK
-
- You can fine tune the DHCP functionality by adding
- these flags to the CONFIG_BOOTP_MASK define:
-
- CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
- serverip from a DHCP server, it is possible that more
- than one DNS serverip is offered to the client.
- If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
- serverip will be stored in the additional environment
- variable "dnsip2". The first DNS serverip is always
- stored in the variable "dnsip", when CONFIG_BOOTP_DNS
- is added to the CONFIG_BOOTP_MASK.
-
- CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
- to do a dynamic update of a DNS server. To do this, they
- need the hostname of the DHCP requester.
- If CONFIG_BOOP_SEND_HOSTNAME is added to the
- CONFIG_BOOTP_MASK, the content of the "hostname"
- environment variable is passed as option 12 to
- the DHCP server.
-
- - CDP Options:
- CONFIG_CDP_DEVICE_ID
-
- The device id used in CDP trigger frames.
-
- CONFIG_CDP_DEVICE_ID_PREFIX
-
- A two character string which is prefixed to the MAC address
- of the device.
-
- CONFIG_CDP_PORT_ID
-
- A printf format string which contains the ascii name of
- the port. Normally is set to "eth%d" which sets
- eth0 for the first ethernet, eth1 for the second etc.
-
- CONFIG_CDP_CAPABILITIES
-
- A 32bit integer which indicates the device capabilities;
- 0x00000010 for a normal host which does not forwards.
-
- CONFIG_CDP_VERSION
-
- An ascii string containing the version of the software.
-
- CONFIG_CDP_PLATFORM
-
- An ascii string containing the name of the platform.
-
- CONFIG_CDP_TRIGGER
-
- A 32bit integer sent on the trigger.
-
- CONFIG_CDP_POWER_CONSUMPTION
-
- A 16bit integer containing the power consumption of the
- device in .1 of milliwatts.
-
- CONFIG_CDP_APPLIANCE_VLAN_TYPE
-
- A byte containing the id of the VLAN.
-
-- Status LED: CONFIG_STATUS_LED
-
- Several configurations allow to display the current
- status using a LED. For instance, the LED will blink
- fast while running U-Boot code, stop blinking as
- soon as a reply to a BOOTP request was received, and
- start blinking slow once the Linux kernel is running
- (supported by a status LED driver in the Linux
- kernel). Defining CONFIG_STATUS_LED enables this
- feature in U-Boot.
-
-- CAN Support: CONFIG_CAN_DRIVER
-
- Defining CONFIG_CAN_DRIVER enables CAN driver support
- on those systems that support this (optional)
- feature, like the TQM8xxL modules.
-
-- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
-
- These enable I2C serial bus commands. Defining either of
- (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
- include the appropriate I2C driver for the selected cpu.
-
- This will allow you to use i2c commands at the u-boot
- command line (as long as you set CFG_CMD_I2C in
- CONFIG_COMMANDS) and communicate with i2c based realtime
- clock chips. See common/cmd_i2c.c for a description of the
- command line interface.
-
- CONFIG_I2C_CMD_TREE is a recommended option that places
- all I2C commands under a single 'i2c' root command. The
- older 'imm', 'imd', 'iprobe' etc. commands are considered
- deprecated and may disappear in the future.
-
- CONFIG_HARD_I2C selects a hardware I2C controller.
-
- CONFIG_SOFT_I2C configures u-boot to use a software (aka
- bit-banging) driver instead of CPM or similar hardware
- support for I2C.
-
- There are several other quantities that must also be
- defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
-
- In both cases you will need to define CFG_I2C_SPEED
- to be the frequency (in Hz) at which you wish your i2c bus
- to run and CFG_I2C_SLAVE to be the address of this node (ie
- the cpu's i2c node address).
-
- Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
- sets the cpu up as a master node and so its address should
- therefore be cleared to 0 (See, eg, MPC823e User's Manual
- p.16-473). So, set CFG_I2C_SLAVE to 0.
-
- That's all that's required for CONFIG_HARD_I2C.
-
- If you use the software i2c interface (CONFIG_SOFT_I2C)
- then the following macros need to be defined (examples are
- from include/configs/lwmon.h):
-
- I2C_INIT
-
- (Optional). Any commands necessary to enable the I2C
- controller or configure ports.
-
- eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
-
- I2C_PORT
-
- (Only for MPC8260 CPU). The I/O port to use (the code
- assumes both bits are on the same port). Valid values
- are 0..3 for ports A..D.
-
- I2C_ACTIVE
-
- The code necessary to make the I2C data line active
- (driven). If the data line is open collector, this
- define can be null.
-
- eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
-
- I2C_TRISTATE
-
- The code necessary to make the I2C data line tri-stated
- (inactive). If the data line is open collector, this
- define can be null.
-
- eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
-
- I2C_READ
-
- Code that returns TRUE if the I2C data line is high,
- FALSE if it is low.
-
- eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
-
- I2C_SDA(bit)
-
- If <bit> is TRUE, sets the I2C data line high. If it
- is FALSE, it clears it (low).
-
- eg: #define I2C_SDA(bit) \
- if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
- else immr->im_cpm.cp_pbdat &= ~PB_SDA
-
- I2C_SCL(bit)
-
- If <bit> is TRUE, sets the I2C clock line high. If it
- is FALSE, it clears it (low).
-
- eg: #define I2C_SCL(bit) \
- if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
- else immr->im_cpm.cp_pbdat &= ~PB_SCL
-
- I2C_DELAY
-
- This delay is invoked four times per clock cycle so this
- controls the rate of data transfer. The data rate thus
- is 1 / (I2C_DELAY * 4). Often defined to be something
- like:
-
- #define I2C_DELAY udelay(2)
-
- CFG_I2C_INIT_BOARD
-
- When a board is reset during an i2c bus transfer
- chips might think that the current transfer is still
- in progress. On some boards it is possible to access
- the i2c SCLK line directly, either by using the
- processor pin as a GPIO or by having a second pin
- connected to the bus. If this option is defined a
- custom i2c_init_board() routine in boards/xxx/board.c
- is run early in the boot sequence.
-
- CONFIG_I2CFAST (PPC405GP|PPC405EP only)
-
- This option enables configuration of bi_iic_fast[] flags
- in u-boot bd_info structure based on u-boot environment
- variable "i2cfast". (see also i2cfast)
-
- CONFIG_I2C_MULTI_BUS
-
- This option allows the use of multiple I2C buses, each of which
- must have a controller. At any point in time, only one bus is
- active. To switch to a different bus, use the 'i2c dev' command.
- Note that bus numbering is zero-based.
-
- CFG_I2C_NOPROBES
-
- This option specifies a list of I2C devices that will be skipped
- when the 'i2c probe' command is issued (or 'iprobe' using the legacy
- command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
- pairs. Otherwise, specify a 1D array of device addresses
-
- e.g.
- #undef CONFIG_I2C_MULTI_BUS
- #define CFG_I2C_NOPROBES {0x50,0x68}
-
- will skip addresses 0x50 and 0x68 on a board with one I2C bus
-
- #define CONFIG_I2C_MULTI_BUS
- #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
-
- will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
-
- CFG_SPD_BUS_NUM
-
- If defined, then this indicates the I2C bus number for DDR SPD.
- If not defined, then U-Boot assumes that SPD is on I2C bus 0.
-
- CONFIG_FSL_I2C
-
- Define this option if you want to use Freescale's I2C driver in
- drivers/fsl_i2c.c.
-
-
-- SPI Support: CONFIG_SPI
-
- Enables SPI driver (so far only tested with
- SPI EEPROM, also an instance works with Crystal A/D and
- D/As on the SACSng board)
-
- CONFIG_SPI_X
-
- Enables extended (16-bit) SPI EEPROM addressing.
- (symmetrical to CONFIG_I2C_X)
-
- CONFIG_SOFT_SPI
-
- Enables a software (bit-bang) SPI driver rather than
- using hardware support. This is a general purpose
- driver that only requires three general I/O port pins
- (two outputs, one input) to function. If this is
- defined, the board configuration must define several
- SPI configuration items (port pins to use, etc). For
- an example, see include/configs/sacsng.h.
-
-- FPGA Support: CONFIG_FPGA_COUNT
-
- Specify the number of FPGA devices to support.
-
- CONFIG_FPGA
-
- Used to specify the types of FPGA devices. For example,
- #define CONFIG_FPGA CFG_XILINX_VIRTEX2
-
- CFG_FPGA_PROG_FEEDBACK
-
- Enable printing of hash marks during FPGA configuration.
-
- CFG_FPGA_CHECK_BUSY
-
- Enable checks on FPGA configuration interface busy
- status by the configuration function. This option
- will require a board or device specific function to
- be written.
-
- CONFIG_FPGA_DELAY
-
- If defined, a function that provides delays in the FPGA
- configuration driver.
-
- CFG_FPGA_CHECK_CTRLC
- Allow Control-C to interrupt FPGA configuration
-
- CFG_FPGA_CHECK_ERROR
-
- Check for configuration errors during FPGA bitfile
- loading. For example, abort during Virtex II
- configuration if the INIT_B line goes low (which
- indicated a CRC error).
-
- CFG_FPGA_WAIT_INIT
-
- Maximum time to wait for the INIT_B line to deassert
- after PROB_B has been deasserted during a Virtex II
- FPGA configuration sequence. The default time is 500
- mS.
-
- CFG_FPGA_WAIT_BUSY
-
- Maximum time to wait for BUSY to deassert during
- Virtex II FPGA configuration. The default is 5 mS.
-
- CFG_FPGA_WAIT_CONFIG
-
- Time to wait after FPGA configuration. The default is
- 200 mS.
-
-- Configuration Management:
- CONFIG_IDENT_STRING
-
- If defined, this string will be added to the U-Boot
- version information (U_BOOT_VERSION)
-
-- Vendor Parameter Protection:
-
- U-Boot considers the values of the environment
- variables "serial#" (Board Serial Number) and
- "ethaddr" (Ethernet Address) to be parameters that
- are set once by the board vendor / manufacturer, and
- protects these variables from casual modification by
- the user. Once set, these variables are read-only,
- and write or delete attempts are rejected. You can
- change this behviour:
-
- If CONFIG_ENV_OVERWRITE is #defined in your config
- file, the write protection for vendor parameters is
- completely disabled. Anybody can change or delete
- these parameters.
-
- Alternatively, if you #define _both_ CONFIG_ETHADDR
- _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
- ethernet address is installed in the environment,
- which can be changed exactly ONCE by the user. [The
- serial# is unaffected by this, i. e. it remains
- read-only.]
-
-- Protected RAM:
- CONFIG_PRAM
-
- Define this variable to enable the reservation of
- "protected RAM", i. e. RAM which is not overwritten
- by U-Boot. Define CONFIG_PRAM to hold the number of
- kB you want to reserve for pRAM. You can overwrite
- this default value by defining an environment
- variable "pram" to the number of kB you want to
- reserve. Note that the board info structure will
- still show the full amount of RAM. If pRAM is
- reserved, a new environment variable "mem" will
- automatically be defined to hold the amount of
- remaining RAM in a form that can be passed as boot
- argument to Linux, for instance like that:
-
- setenv bootargs ... mem=\${mem}
- saveenv
-
- This way you can tell Linux not to use this memory,
- either, which results in a memory region that will
- not be affected by reboots.
-
- *WARNING* If your board configuration uses automatic
- detection of the RAM size, you must make sure that
- this memory test is non-destructive. So far, the
- following board configurations are known to be
- "pRAM-clean":
-
- ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
- HERMES, IP860, RPXlite, LWMON, LANTEC,
- PCU_E, FLAGADM, TQM8260
-
-- Error Recovery:
- CONFIG_PANIC_HANG
-
- Define this variable to stop the system in case of a
- fatal error, so that you have to reset it manually.
- This is probably NOT a good idea for an embedded
- system where you want to system to reboot
- automatically as fast as possible, but it may be
- useful during development since you can try to debug
- the conditions that lead to the situation.
-
- CONFIG_NET_RETRY_COUNT
-
- This variable defines the number of retries for
- network operations like ARP, RARP, TFTP, or BOOTP
- before giving up the operation. If not defined, a
- default value of 5 is used.
-
-- Command Interpreter:
- CONFIG_AUTO_COMPLETE
-
- Enable auto completion of commands using TAB.
-
- Note that this feature has NOT been implemented yet
- for the "hush" shell.
-
-
- CFG_HUSH_PARSER
-
- Define this variable to enable the "hush" shell (from
- Busybox) as command line interpreter, thus enabling
- powerful command line syntax like
- if...then...else...fi conditionals or `&&' and '||'
- constructs ("shell scripts").
-
- If undefined, you get the old, much simpler behaviour
- with a somewhat smaller memory footprint.
-
-
- CFG_PROMPT_HUSH_PS2
-
- This defines the secondary prompt string, which is
- printed when the command interpreter needs more input
- to complete a command. Usually "> ".
-
- Note:
-
- In the current implementation, the local variables
- space and global environment variables space are
- separated. Local variables are those you define by
- simply typing `name=value'. To access a local
- variable later on, you have write `$name' or
- `${name}'; to execute the contents of a variable
- directly type `$name' at the command prompt.
-
- Global environment variables are those you use
- setenv/printenv to work with. To run a command stored
- in such a variable, you need to use the run command,
- and you must not use the '$' sign to access them.
-
- To store commands and special characters in a
- variable, please use double quotation marks
- surrounding the whole text of the variable, instead
- of the backslashes before semicolons and special
- symbols.
-
-- Commandline Editing and History:
- CONFIG_CMDLINE_EDITING
-
- Enable editiong and History functions for interactive
- commandline input operations
-
-- Default Environment:
- CONFIG_EXTRA_ENV_SETTINGS
-
- Define this to contain any number of null terminated
- strings (variable = value pairs) that will be part of
- the default environment compiled into the boot image.
-
- For example, place something like this in your
- board's config file:
-
- #define CONFIG_EXTRA_ENV_SETTINGS \
- "myvar1=value1\0" \
- "myvar2=value2\0"
-
- Warning: This method is based on knowledge about the
- internal format how the environment is stored by the
- U-Boot code. This is NOT an official, exported
- interface! Although it is unlikely that this format
- will change soon, there is no guarantee either.
- You better know what you are doing here.
-
- Note: overly (ab)use of the default environment is
- discouraged. Make sure to check other ways to preset
- the environment like the autoscript function or the
- boot command first.
-
-- SystemACE Support:
- CONFIG_SYSTEMACE
-
- Adding this option adds support for Xilinx SystemACE
- chips attached via some sort of local bus. The address
- of the chip must alsh be defined in the
- CFG_SYSTEMACE_BASE macro. For example:
-
- #define CONFIG_SYSTEMACE
- #define CFG_SYSTEMACE_BASE 0xf0000000
-
- When SystemACE support is added, the "ace" device type
- becomes available to the fat commands, i.e. fatls.
-
-- TFTP Fixed UDP Port:
- CONFIG_TFTP_PORT
-
- If this is defined, the environment variable tftpsrcp
- is used to supply the TFTP UDP source port value.
- If tftpsrcp isn't defined, the normal pseudo-random port
- number generator is used.
-
- Also, the environment variable tftpdstp is used to supply
- the TFTP UDP destination port value. If tftpdstp isn't
- defined, the normal port 69 is used.
-
- The purpose for tftpsrcp is to allow a TFTP server to
- blindly start the TFTP transfer using the pre-configured
- target IP address and UDP port. This has the effect of
- "punching through" the (Windows XP) firewall, allowing
- the remainder of the TFTP transfer to proceed normally.
- A better solution is to properly configure the firewall,
- but sometimes that is not allowed.
-
-- Show boot progress:
- CONFIG_SHOW_BOOT_PROGRESS
-
- Defining this option allows to add some board-
- specific code (calling a user-provided function
- "show_boot_progress(int)") that enables you to show
- the system's boot progress on some display (for
- example, some LED's) on your board. At the moment,
- the following checkpoints are implemented:
-
- Arg Where When
- 1 common/cmd_bootm.c before attempting to boot an image
- -1 common/cmd_bootm.c Image header has bad magic number
- 2 common/cmd_bootm.c Image header has correct magic number
- -2 common/cmd_bootm.c Image header has bad checksum
- 3 common/cmd_bootm.c Image header has correct checksum
- -3 common/cmd_bootm.c Image data has bad checksum
- 4 common/cmd_bootm.c Image data has correct checksum
- -4 common/cmd_bootm.c Image is for unsupported architecture
- 5 common/cmd_bootm.c Architecture check OK
- -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
- 6 common/cmd_bootm.c Image Type check OK
- -6 common/cmd_bootm.c gunzip uncompression error
- -7 common/cmd_bootm.c Unimplemented compression type
- 7 common/cmd_bootm.c Uncompression OK
- -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
- 8 common/cmd_bootm.c Image Type check OK
- -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
- 9 common/cmd_bootm.c Start initial ramdisk verification
- -10 common/cmd_bootm.c Ramdisk header has bad magic number
- -11 common/cmd_bootm.c Ramdisk header has bad checksum
- 10 common/cmd_bootm.c Ramdisk header is OK
- -12 common/cmd_bootm.c Ramdisk data has bad checksum
- 11 common/cmd_bootm.c Ramdisk data has correct checksum
- 12 common/cmd_bootm.c Ramdisk verification complete, start loading
- -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
- 13 common/cmd_bootm.c Start multifile image verification
- 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
- 15 common/cmd_bootm.c All preparation done, transferring control to OS
-
- -30 lib_ppc/board.c Fatal error, hang the system
- -31 post/post.c POST test failed, detected by post_output_backlog()
- -32 post/post.c POST test failed, detected by post_run_single()
-
- -1 common/cmd_doc.c Bad usage of "doc" command
- -1 common/cmd_doc.c No boot device
- -1 common/cmd_doc.c Unknown Chip ID on boot device
- -1 common/cmd_doc.c Read Error on boot device
- -1 common/cmd_doc.c Image header has bad magic number
-
- -1 common/cmd_ide.c Bad usage of "ide" command
- -1 common/cmd_ide.c No boot device
- -1 common/cmd_ide.c Unknown boot device
- -1 common/cmd_ide.c Unknown partition table
- -1 common/cmd_ide.c Invalid partition type
- -1 common/cmd_ide.c Read Error on boot device
- -1 common/cmd_ide.c Image header has bad magic number
-
- -1 common/cmd_nand.c Bad usage of "nand" command
- -1 common/cmd_nand.c No boot device
- -1 common/cmd_nand.c Unknown Chip ID on boot device
- -1 common/cmd_nand.c Read Error on boot device
- -1 common/cmd_nand.c Image header has bad magic number
-
- -1 common/env_common.c Environment has a bad CRC, using default
-
-- Interrupt support (PPC):
-
- There are common interrupt_init() and timer_interrupt()
- for all PPC archs. interrupt_init() calls interrupt_init_cpu()
- for cpu specific initialization. interrupt_init_cpu()
- should set decrementer_count to appropriate value. If
- cpu resets decrementer automatically after interrupt
- (ppc4xx) it should set decrementer_count to zero.
- timer_interrupt() calls timer_interrupt_cpu() for cpu
- specific handling. If board has watchdog / status_led
- / other_activity_monitor it works automatically from
- general timer_interrupt().
-
-- General:
-
- In the target system modem support is enabled when a
- specific key (key combination) is pressed during
- power-on. Otherwise U-Boot will boot normally
- (autoboot). The key_pressed() fuction is called from
- board_init(). Currently key_pressed() is a dummy
- function, returning 1 and thus enabling modem
- initialization.
-
- If there are no modem init strings in the
- environment, U-Boot proceed to autoboot; the
- previous output (banner, info printfs) will be
- supressed, though.
-
- See also: doc/README.Modem
-
-
-Configuration Settings:
------------------------
-
-- CFG_LONGHELP: Defined when you want long help messages included;
- undefine this when you're short of memory.
-
-- CFG_PROMPT: This is what U-Boot prints on the console to
- prompt for user input.
-
-- CFG_CBSIZE: Buffer size for input from the Console
-
-- CFG_PBSIZE: Buffer size for Console output
-
-- CFG_MAXARGS: max. Number of arguments accepted for monitor commands
-
-- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
- the application (usually a Linux kernel) when it is
- booted
-
-- CFG_BAUDRATE_TABLE:
- List of legal baudrate settings for this board.
-
-- CFG_CONSOLE_INFO_QUIET
- Suppress display of console information at boot.
-
-- CFG_CONSOLE_IS_IN_ENV
- If the board specific function
- extern int overwrite_console (void);
- returns 1, the stdin, stderr and stdout are switched to the
- serial port, else the settings in the environment are used.
-
-- CFG_CONSOLE_OVERWRITE_ROUTINE
- Enable the call to overwrite_console().
-
-- CFG_CONSOLE_ENV_OVERWRITE
- Enable overwrite of previous console environment settings.
-
-- CFG_MEMTEST_START, CFG_MEMTEST_END:
- Begin and End addresses of the area used by the
- simple memory test.
-
-- CFG_ALT_MEMTEST:
- Enable an alternate, more extensive memory test.
-
-- CFG_MEMTEST_SCRATCH:
- Scratch address used by the alternate memory test
- You only need to set this if address zero isn't writeable
-
-- CFG_TFTP_LOADADDR:
- Default load address for network file downloads
-
-- CFG_LOADS_BAUD_CHANGE:
- Enable temporary baudrate change while serial download
-
-- CFG_SDRAM_BASE:
- Physical start address of SDRAM. _Must_ be 0 here.
-
-- CFG_MBIO_BASE:
- Physical start address of Motherboard I/O (if using a
- Cogent motherboard)
-
-- CFG_FLASH_BASE:
- Physical start address of Flash memory.
-
-- CFG_MONITOR_BASE:
- Physical start address of boot monitor code (set by
- make config files to be same as the text base address
- (TEXT_BASE) used when linking) - same as
- CFG_FLASH_BASE when booting from flash.
-
-- CFG_MONITOR_LEN:
- Size of memory reserved for monitor code, used to
- determine _at_compile_time_ (!) if the environment is
- embedded within the U-Boot image, or in a separate
- flash sector.
-
-- CFG_MALLOC_LEN:
- Size of DRAM reserved for malloc() use.
-
-- CFG_BOOTM_LEN:
- Normally compressed uImages are limited to an
- uncompressed size of 8 MBytes. If this is not enough,
- you can define CFG_BOOTM_LEN in your board config file
- to adjust this setting to your needs.
-
-- CFG_BOOTMAPSZ:
- Maximum size of memory mapped by the startup code of
- the Linux kernel; all data that must be processed by
- the Linux kernel (bd_info, boot arguments, eventually
- initrd image) must be put below this limit.
-
-- CFG_MAX_FLASH_BANKS:
- Max number of Flash memory banks
-
-- CFG_MAX_FLASH_SECT:
- Max number of sectors on a Flash chip
-
-- CFG_FLASH_ERASE_TOUT:
- Timeout for Flash erase operations (in ms)
-
-- CFG_FLASH_WRITE_TOUT:
- Timeout for Flash write operations (in ms)
-
-- CFG_FLASH_LOCK_TOUT
- Timeout for Flash set sector lock bit operation (in ms)
-
-- CFG_FLASH_UNLOCK_TOUT
- Timeout for Flash clear lock bits operation (in ms)
-
-- CFG_FLASH_PROTECTION
- If defined, hardware flash sectors protection is used
- instead of U-Boot software protection.
-
-- CFG_DIRECT_FLASH_TFTP:
-
- Enable TFTP transfers directly to flash memory;
- without this option such a download has to be
- performed in two steps: (1) download to RAM, and (2)
- copy from RAM to flash.
-
- The two-step approach is usually more reliable, since
- you can check if the download worked before you erase
- the flash, but in some situations (when sytem RAM is
- too limited to allow for a tempory copy of the
- downloaded image) this option may be very useful.
-
-- CFG_FLASH_CFI:
- Define if the flash driver uses extra elements in the
- common flash structure for storing flash geometry.
-
-- CFG_FLASH_CFI_DRIVER
- This option also enables the building of the cfi_flash driver
- in the drivers directory
-
-- CFG_FLASH_QUIET_TEST
- If this option is defined, the common CFI flash doesn't
- print it's warning upon not recognized FLASH banks. This
- is useful, if some of the configured banks are only
- optionally available.
-
-- CFG_RX_ETH_BUFFER:
- Defines the number of ethernet receive buffers. On some
- ethernet controllers it is recommended to set this value
- to 8 or even higher (EEPRO100 or 405 EMAC), since all
- buffers can be full shortly after enabling the interface
- on high ethernet traffic.
- Defaults to 4 if not defined.
-
-The following definitions that deal with the placement and management
-of environment data (variable area); in general, we support the
-following configurations:
-
-- CFG_ENV_IS_IN_FLASH:
-
- Define this if the environment is in flash memory.
-
- a) The environment occupies one whole flash sector, which is
- "embedded" in the text segment with the U-Boot code. This
- happens usually with "bottom boot sector" or "top boot
- sector" type flash chips, which have several smaller
- sectors at the start or the end. For instance, such a
- layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
- such a case you would place the environment in one of the
- 4 kB sectors - with U-Boot code before and after it. With
- "top boot sector" type flash chips, you would put the
- environment in one of the last sectors, leaving a gap
- between U-Boot and the environment.
-
- - CFG_ENV_OFFSET:
-
- Offset of environment data (variable area) to the
- beginning of flash memory; for instance, with bottom boot
- type flash chips the second sector can be used: the offset
- for this sector is given here.
-
- CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
-
- - CFG_ENV_ADDR:
-
- This is just another way to specify the start address of
- the flash sector containing the environment (instead of
- CFG_ENV_OFFSET).
-
- - CFG_ENV_SECT_SIZE:
-
- Size of the sector containing the environment.
-
-
- b) Sometimes flash chips have few, equal sized, BIG sectors.
- In such a case you don't want to spend a whole sector for
- the environment.
-
- - CFG_ENV_SIZE:
-
- If you use this in combination with CFG_ENV_IS_IN_FLASH
- and CFG_ENV_SECT_SIZE, you can specify to use only a part
- of this flash sector for the environment. This saves
- memory for the RAM copy of the environment.
-
- It may also save flash memory if you decide to use this
- when your environment is "embedded" within U-Boot code,
- since then the remainder of the flash sector could be used
- for U-Boot code. It should be pointed out that this is
- STRONGLY DISCOURAGED from a robustness point of view:
- updating the environment in flash makes it always
- necessary to erase the WHOLE sector. If something goes
- wrong before the contents has been restored from a copy in
- RAM, your target system will be dead.
-
- - CFG_ENV_ADDR_REDUND
- CFG_ENV_SIZE_REDUND
-
- These settings describe a second storage area used to hold
- a redundand copy of the environment data, so that there is
- a valid backup copy in case there is a power failure during
- a "saveenv" operation.
-
-BE CAREFUL! Any changes to the flash layout, and some changes to the
-source code will make it necessary to adapt <board>/u-boot.lds*
-accordingly!
-
-
-- CFG_ENV_IS_IN_NVRAM:
-
- Define this if you have some non-volatile memory device
- (NVRAM, battery buffered SRAM) which you want to use for the
- environment.
-
- - CFG_ENV_ADDR:
- - CFG_ENV_SIZE:
-
- These two #defines are used to determin the memory area you
- want to use for environment. It is assumed that this memory
- can just be read and written to, without any special
- provision.
-
-BE CAREFUL! The first access to the environment happens quite early
-in U-Boot initalization (when we try to get the setting of for the
-console baudrate). You *MUST* have mappend your NVRAM area then, or
-U-Boot will hang.
-
-Please note that even with NVRAM we still use a copy of the
-environment in RAM: we could work on NVRAM directly, but we want to
-keep settings there always unmodified except somebody uses "saveenv"
-to save the current settings.
-
-
-- CFG_ENV_IS_IN_EEPROM:
-
- Use this if you have an EEPROM or similar serial access
- device and a driver for it.
-
- - CFG_ENV_OFFSET:
- - CFG_ENV_SIZE:
-
- These two #defines specify the offset and size of the
- environment area within the total memory of your EEPROM.
-
- - CFG_I2C_EEPROM_ADDR:
- If defined, specified the chip address of the EEPROM device.
- The default address is zero.
-
- - CFG_EEPROM_PAGE_WRITE_BITS:
- If defined, the number of bits used to address bytes in a
- single page in the EEPROM device. A 64 byte page, for example
- would require six bits.
-
- - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
- If defined, the number of milliseconds to delay between
- page writes. The default is zero milliseconds.
-
- - CFG_I2C_EEPROM_ADDR_LEN:
- The length in bytes of the EEPROM memory array address. Note
- that this is NOT the chip address length!
-
- - CFG_I2C_EEPROM_ADDR_OVERFLOW:
- EEPROM chips that implement "address overflow" are ones
- like Catalyst 24WC04/08/16 which has 9/10/11 bits of
- address and the extra bits end up in the "chip address" bit
- slots. This makes a 24WC08 (1Kbyte) chip look like four 256
- byte chips.
-
- Note that we consider the length of the address field to
- still be one byte because the extra address bits are hidden
- in the chip address.
-
- - CFG_EEPROM_SIZE:
- The size in bytes of the EEPROM device.
-
-
-- CFG_ENV_IS_IN_DATAFLASH:
-
- Define this if you have a DataFlash memory device which you
- want to use for the environment.
-
- - CFG_ENV_OFFSET:
- - CFG_ENV_ADDR:
- - CFG_ENV_SIZE:
-
- These three #defines specify the offset and size of the
- environment area within the total memory of your DataFlash placed
- at the specified address.
-
-- CFG_ENV_IS_IN_NAND:
-
- Define this if you have a NAND device which you want to use
- for the environment.
-
- - CFG_ENV_OFFSET:
- - CFG_ENV_SIZE:
-
- These two #defines specify the offset and size of the environment
- area within the first NAND device.
-
- - CFG_ENV_OFFSET_REDUND
-
- This setting describes a second storage area of CFG_ENV_SIZE
- size used to hold a redundant copy of the environment data,
- so that there is a valid backup copy in case there is a
- power failure during a "saveenv" operation.
-
- Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
- to a block boundary, and CFG_ENV_SIZE must be a multiple of
- the NAND devices block size.
-
-- CFG_SPI_INIT_OFFSET
-
- Defines offset to the initial SPI buffer area in DPRAM. The
- area is used at an early stage (ROM part) if the environment
- is configured to reside in the SPI EEPROM: We need a 520 byte
- scratch DPRAM area. It is used between the two initialization
- calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
- to be a good choice since it makes it far enough from the
- start of the data area as well as from the stack pointer.
-
-Please note that the environment is read-only as long as the monitor
-has been relocated to RAM and a RAM copy of the environment has been
-created; also, when using EEPROM you will have to use getenv_r()
-until then to read environment variables.
-
-The environment is protected by a CRC32 checksum. Before the monitor
-is relocated into RAM, as a result of a bad CRC you will be working
-with the compiled-in default environment - *silently*!!! [This is
-necessary, because the first environment variable we need is the
-"baudrate" setting for the console - if we have a bad CRC, we don't
-have any device yet where we could complain.]
-
-Note: once the monitor has been relocated, then it will complain if
-the default environment is used; a new CRC is computed as soon as you
-use the "saveenv" command to store a valid environment.
-
-- CFG_FAULT_ECHO_LINK_DOWN:
- Echo the inverted Ethernet link state to the fault LED.
-
- Note: If this option is active, then CFG_FAULT_MII_ADDR
- also needs to be defined.
-
-- CFG_FAULT_MII_ADDR:
- MII address of the PHY to check for the Ethernet link state.
-
-- CFG_64BIT_VSPRINTF:
- Makes vsprintf (and all *printf functions) support printing
- of 64bit values by using the L quantifier
-
-- CFG_64BIT_STRTOUL:
- Adds simple_strtoull that returns a 64bit value
-
-Low Level (hardware related) configuration options:
----------------------------------------------------
-
-- CFG_CACHELINE_SIZE:
- Cache Line Size of the CPU.
-
-- CFG_DEFAULT_IMMR:
- Default address of the IMMR after system reset.
-
- Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
- and RPXsuper) to be able to adjust the position of
- the IMMR register after a reset.
-
-- Floppy Disk Support:
- CFG_FDC_DRIVE_NUMBER
-
- the default drive number (default value 0)
-
- CFG_ISA_IO_STRIDE
-
- defines the spacing between fdc chipset registers
- (default value 1)
-
- CFG_ISA_IO_OFFSET
-
- defines the offset of register from address. It
- depends on which part of the data bus is connected to
- the fdc chipset. (default value 0)
-
- If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
- CFG_FDC_DRIVE_NUMBER are undefined, they take their
- default value.
-
- if CFG_FDC_HW_INIT is defined, then the function
- fdc_hw_init() is called at the beginning of the FDC
- setup. fdc_hw_init() must be provided by the board
- source code. It is used to make hardware dependant
- initializations.
-
-- CFG_IMMR: Physical address of the Internal Memory.
- DO NOT CHANGE unless you know exactly what you're
- doing! (11-4) [MPC8xx/82xx systems only]
-
-- CFG_INIT_RAM_ADDR:
-
- Start address of memory area that can be used for
- initial data and stack; please note that this must be
- writable memory that is working WITHOUT special
- initialization, i. e. you CANNOT use normal RAM which
- will become available only after programming the
- memory controller and running certain initialization
- sequences.
-
- U-Boot uses the following memory types:
- - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
- - MPC824X: data cache
- - PPC4xx: data cache
-
-- CFG_GBL_DATA_OFFSET:
-
- Offset of the initial data structure in the memory
- area defined by CFG_INIT_RAM_ADDR. Usually
- CFG_GBL_DATA_OFFSET is chosen such that the initial
- data is located at the end of the available space
- (sometimes written as (CFG_INIT_RAM_END -
- CFG_INIT_DATA_SIZE), and the initial stack is just
- below that area (growing from (CFG_INIT_RAM_ADDR +
- CFG_GBL_DATA_OFFSET) downward.
-
- Note:
- On the MPC824X (or other systems that use the data
- cache for initial memory) the address chosen for
- CFG_INIT_RAM_ADDR is basically arbitrary - it must
- point to an otherwise UNUSED address space between
- the top of RAM and the start of the PCI space.
-
-- CFG_SIUMCR: SIU Module Configuration (11-6)
-
-- CFG_SYPCR: System Protection Control (11-9)
-
-- CFG_TBSCR: Time Base Status and Control (11-26)
-
-- CFG_PISCR: Periodic Interrupt Status and Control (11-31)
-
-- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
-
-- CFG_SCCR: System Clock and reset Control Register (15-27)
-
-- CFG_OR_TIMING_SDRAM:
- SDRAM timing
-
-- CFG_MAMR_PTA:
- periodic timer for refresh
-
-- CFG_DER: Debug Event Register (37-47)
-
-- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
- CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
- CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
- CFG_BR1_PRELIM:
- Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
-
-- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
- CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
- CFG_OR3_PRELIM, CFG_BR3_PRELIM:
- Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
-
-- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
- CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
- Machine Mode Register and Memory Periodic Timer
- Prescaler definitions (SDRAM timing)
-
-- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
- enable I2C microcode relocation patch (MPC8xx);
- define relocation offset in DPRAM [DSP2]
-
-- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
- enable SPI microcode relocation patch (MPC8xx);
- define relocation offset in DPRAM [SCC4]
-
-- CFG_USE_OSCCLK:
- Use OSCM clock mode on MBX8xx board. Be careful,
- wrong setting might damage your board. Read
- doc/README.MBX before setting this variable!
-
-- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
- Offset of the bootmode word in DPRAM used by post
- (Power On Self Tests). This definition overrides
- #define'd default value in commproc.h resp.
- cpm_8260.h.
-
-- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
- CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
- CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
- CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
- CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
- CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
- CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
- CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
- Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
-
-- CONFIG_SPD_EEPROM
- Get DDR timing information from an I2C EEPROM. Common with pluggable
- memory modules such as SODIMMs
- SPD_EEPROM_ADDRESS
- I2C address of the SPD EEPROM
-
-- CFG_SPD_BUS_NUM
- If SPD EEPROM is on an I2C bus other than the first one, specify here.
- Note that the value must resolve to something your driver can deal with.
-
-- CFG_83XX_DDR_USES_CS0
- Only for 83xx systems. If specified, then DDR should be configured
- using CS0 and CS1 instead of CS2 and CS3.
-
-- CFG_83XX_DDR_USES_CS0
- Only for 83xx systems. If specified, then DDR should be configured
- using CS0 and CS1 instead of CS2 and CS3.
-
-- CONFIG_ETHER_ON_FEC[12]
- Define to enable FEC[12] on a 8xx series processor.
-
-- CONFIG_FEC[12]_PHY
- Define to the hardcoded PHY address which corresponds
- to the given FEC; i. e.
- #define CONFIG_FEC1_PHY 4
- means that the PHY with address 4 is connected to FEC1
-
- When set to -1, means to probe for first available.
-
-- CONFIG_FEC[12]_PHY_NORXERR
- The PHY does not have a RXERR line (RMII only).
- (so program the FEC to ignore it).
-
-- CONFIG_RMII
- Enable RMII mode for all FECs.
- Note that this is a global option, we can't
- have one FEC in standard MII mode and another in RMII mode.
-
-- CONFIG_CRC32_VERIFY
- Add a verify option to the crc32 command.
- The syntax is:
-
- => crc32 -v <address> <count> <crc32>
-
- Where address/count indicate a memory area
- and crc32 is the correct crc32 which the
- area should have.
-
-- CONFIG_LOOPW
- Add the "loopw" memory command. This only takes effect if
- the memory commands are activated globally (CFG_CMD_MEM).
-
-- CONFIG_MX_CYCLIC
- Add the "mdc" and "mwc" memory commands. These are cyclic
- "md/mw" commands.
- Examples:
-
- => mdc.b 10 4 500
- This command will print 4 bytes (10,11,12,13) each 500 ms.
-
- => mwc.l 100 12345678 10
- This command will write 12345678 to address 100 all 10 ms.
-
- This only takes effect if the memory commands are activated
- globally (CFG_CMD_MEM).
-
-- CONFIG_SKIP_LOWLEVEL_INIT
-- CONFIG_SKIP_RELOCATE_UBOOT
-
- [ARM only] If these variables are defined, then
- certain low level initializations (like setting up
- the memory controller) are omitted and/or U-Boot does
- not relocate itself into RAM.
- Normally these variables MUST NOT be defined. The
- only exception is when U-Boot is loaded (to RAM) by
- some other boot loader or by a debugger which
- performs these intializations itself.
-
-
-Building the Software:
-======================
-
-Building U-Boot has been tested in native PPC environments (on a
-PowerBook G3 running LinuxPPC 2000) and in cross environments
-(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
-NetBSD 1.5 on x86).
-
-If you are not using a native PPC environment, it is assumed that you
-have the GNU cross compiling tools available in your path and named
-with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
-you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
-the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
-change it to:
-
- CROSS_COMPILE = ppc_4xx-
-
-
-U-Boot is intended to be simple to build. After installing the
-sources you must configure U-Boot for one specific board type. This
-is done by typing:
-
- make NAME_config
-
-where "NAME_config" is the name of one of the existing
-configurations; the following names are supported:
-
- ADCIOP_config FPS860L_config omap730p2_config
- ADS860_config GEN860T_config pcu_e_config
- Alaska8220_config
- AR405_config GENIETV_config PIP405_config
- at91rm9200dk_config GTH_config QS823_config
- CANBT_config hermes_config QS850_config
- cmi_mpc5xx_config hymod_config QS860T_config
- cogent_common_config IP860_config RPXlite_config
- cogent_mpc8260_config IVML24_config RPXlite_DW_config
- cogent_mpc8xx_config IVMS8_config RPXsuper_config
- CPCI405_config JSE_config rsdproto_config
- CPCIISER4_config LANTEC_config Sandpoint8240_config
- csb272_config lwmon_config sbc8260_config
- CU824_config MBX860T_config sbc8560_33_config
- DUET_ADS_config MBX_config sbc8560_66_config
- EBONY_config MPC8260ADS_config SM850_config
- ELPT860_config MPC8540ADS_config SPD823TS_config
- ESTEEM192E_config MPC8540EVAL_config stxgp3_config
- ETX094_config MPC8560ADS_config SXNI855T_config
- FADS823_config NETVIA_config TQM823L_config
- FADS850SAR_config omap1510inn_config TQM850L_config
- FADS860T_config omap1610h2_config TQM855L_config
- FPS850L_config omap1610inn_config TQM860L_config
- omap5912osk_config walnut_config
- omap2420h4_config Yukon8220_config
- ZPC1900_config
-
-Note: for some board special configuration names may exist; check if
- additional information is available from the board vendor; for
- instance, the TQM823L systems are available without (standard)
- or with LCD support. You can select such additional "features"
- when chosing the configuration, i. e.
-
- make TQM823L_config
- - will configure for a plain TQM823L, i. e. no LCD support
-
- make TQM823L_LCD_config
- - will configure for a TQM823L with U-Boot console on LCD
-
- etc.
-
-
-Finally, type "make all", and you should get some working U-Boot
-images ready for download to / installation on your system:
-
-- "u-boot.bin" is a raw binary image
-- "u-boot" is an image in ELF binary format
-- "u-boot.srec" is in Motorola S-Record format
-
-By default the build is performed locally and the objects are saved
-in the source directory. One of the two methods can be used to change
-this behavior and build U-Boot to some external directory:
-
-1. Add O= to the make command line invocations:
-
- make O=/tmp/build distclean
- make O=/tmp/build NAME_config
- make O=/tmp/build all
-
-2. Set environment variable BUILD_DIR to point to the desired location:
-
- export BUILD_DIR=/tmp/build
- make distclean
- make NAME_config
- make all
-
-Note that the command line "O=" setting overrides the BUILD_DIR environment
-variable.
-
-
-Please be aware that the Makefiles assume you are using GNU make, so
-for instance on NetBSD you might need to use "gmake" instead of
-native "make".
-
-
-If the system board that you have is not listed, then you will need
-to port U-Boot to your hardware platform. To do this, follow these
-steps:
-
-1. Add a new configuration option for your board to the toplevel
- "Makefile" and to the "MAKEALL" script, using the existing
- entries as examples. Note that here and at many other places
- boards and other names are listed in alphabetical sort order. Please
- keep this order.
-2. Create a new directory to hold your board specific code. Add any
- files you need. In your board directory, you will need at least
- the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
-3. Create a new configuration file "include/configs/<board>.h" for
- your board
-3. If you're porting U-Boot to a new CPU, then also create a new
- directory to hold your CPU specific code. Add any files you need.
-4. Run "make <board>_config" with your new name.
-5. Type "make", and you should get a working "u-boot.srec" file
- to be installed on your target system.
-6. Debug and solve any problems that might arise.
- [Of course, this last step is much harder than it sounds.]
-
-
-Testing of U-Boot Modifications, Ports to New Hardware, etc.:
-==============================================================
-
-If you have modified U-Boot sources (for instance added a new board
-or support for new devices, a new CPU, etc.) you are expected to
-provide feedback to the other developers. The feedback normally takes
-the form of a "patch", i. e. a context diff against a certain (latest
-official or latest in CVS) version of U-Boot sources.
-
-But before you submit such a patch, please verify that your modifi-
-cation did not break existing code. At least make sure that *ALL* of
-the supported boards compile WITHOUT ANY compiler warnings. To do so,
-just run the "MAKEALL" script, which will configure and build U-Boot
-for ALL supported system. Be warned, this will take a while. You can
-select which (cross) compiler to use by passing a `CROSS_COMPILE'
-environment variable to the script, i. e. to use the cross tools from
-MontaVista's Hard Hat Linux you can type
-
- CROSS_COMPILE=ppc_8xx- MAKEALL
-
-or to build on a native PowerPC system you can type
-
- CROSS_COMPILE=' ' MAKEALL
-
-When using the MAKEALL script, the default behaviour is to build U-Boot
-in the source directory. This location can be changed by setting the
-BUILD_DIR environment variable. Also, for each target built, the MAKEALL
-script saves two log files (<target>.ERR and <target>.MAKEALL) in the
-<source dir>/LOG directory. This default location can be changed by
-setting the MAKEALL_LOGDIR environment variable. For example:
-
- export BUILD_DIR=/tmp/build
- export MAKEALL_LOGDIR=/tmp/log
- CROSS_COMPILE=ppc_8xx- MAKEALL
-
-With the above settings build objects are saved in the /tmp/build, log
-files are saved in the /tmp/log and the source tree remains clean during
-the whole build process.
-
-
-See also "U-Boot Porting Guide" below.
-
-
-Monitor Commands - Overview:
-============================
-
-go - start application at address 'addr'
-run - run commands in an environment variable
-bootm - boot application image from memory
-bootp - boot image via network using BootP/TFTP protocol
-tftpboot- boot image via network using TFTP protocol
- and env variables "ipaddr" and "serverip"
- (and eventually "gatewayip")
-rarpboot- boot image via network using RARP/TFTP protocol
-diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
-loads - load S-Record file over serial line
-loadb - load binary file over serial line (kermit mode)
-md - memory display
-mm - memory modify (auto-incrementing)
-nm - memory modify (constant address)
-mw - memory write (fill)
-cp - memory copy
-cmp - memory compare
-crc32 - checksum calculation
-imd - i2c memory display
-imm - i2c memory modify (auto-incrementing)
-inm - i2c memory modify (constant address)
-imw - i2c memory write (fill)
-icrc32 - i2c checksum calculation
-iprobe - probe to discover valid I2C chip addresses
-iloop - infinite loop on address range
-isdram - print SDRAM configuration information
-sspi - SPI utility commands
-base - print or set address offset
-printenv- print environment variables
-setenv - set environment variables
-saveenv - save environment variables to persistent storage
-protect - enable or disable FLASH write protection
-erase - erase FLASH memory
-flinfo - print FLASH memory information
-bdinfo - print Board Info structure
-iminfo - print header information for application image
-coninfo - print console devices and informations
-ide - IDE sub-system
-loop - infinite loop on address range
-loopw - infinite write loop on address range
-mtest - simple RAM test
-icache - enable or disable instruction cache
-dcache - enable or disable data cache
-reset - Perform RESET of the CPU
-echo - echo args to console
-version - print monitor version
-help - print online help
-? - alias for 'help'
-
-
-Monitor Commands - Detailed Description:
-========================================
-
-TODO.
-
-For now: just type "help <command>".
-
-
-Environment Variables:
-======================
-
-U-Boot supports user configuration using Environment Variables which
-can be made persistent by saving to Flash memory.
-
-Environment Variables are set using "setenv", printed using
-"printenv", and saved to Flash using "saveenv". Using "setenv"
-without a value can be used to delete a variable from the
-environment. As long as you don't save the environment you are
-working with an in-memory copy. In case the Flash area containing the
-environment is erased by accident, a default environment is provided.
-
-Some configuration options can be set using Environment Variables:
-
- baudrate - see CONFIG_BAUDRATE
-
- bootdelay - see CONFIG_BOOTDELAY
-
- bootcmd - see CONFIG_BOOTCOMMAND
-
- bootargs - Boot arguments when booting an RTOS image
-
- bootfile - Name of the image to load with TFTP
-
- autostart - if set to "yes", an image loaded using the "bootp",
- "rarpboot", "tftpboot" or "diskboot" commands will
- be automatically started (by internally calling
- "bootm")
-
- If set to "no", a standalone image passed to the
- "bootm" command will be copied to the load address
- (and eventually uncompressed), but NOT be started.
- This can be used to load and uncompress arbitrary
- data.
-
- i2cfast - (PPC405GP|PPC405EP only)
- if set to 'y' configures Linux I2C driver for fast
- mode (400kHZ). This environment variable is used in
- initialization code. So, for changes to be effective
- it must be saved and board must be reset.
-
- initrd_high - restrict positioning of initrd images:
- If this variable is not set, initrd images will be
- copied to the highest possible address in RAM; this
- is usually what you want since it allows for
- maximum initrd size. If for some reason you want to
- make sure that the initrd image is loaded below the
- CFG_BOOTMAPSZ limit, you can set this environment
- variable to a value of "no" or "off" or "0".
- Alternatively, you can set it to a maximum upper
- address to use (U-Boot will still check that it
- does not overwrite the U-Boot stack and data).
-
- For instance, when you have a system with 16 MB
- RAM, and want to reserve 4 MB from use by Linux,
- you can do this by adding "mem=12M" to the value of
- the "bootargs" variable. However, now you must make
- sure that the initrd image is placed in the first
- 12 MB as well - this can be done with
-
- setenv initrd_high 00c00000
-
- If you set initrd_high to 0xFFFFFFFF, this is an
- indication to U-Boot that all addresses are legal
- for the Linux kernel, including addresses in flash
- memory. In this case U-Boot will NOT COPY the
- ramdisk at all. This may be useful to reduce the
- boot time on your system, but requires that this
- feature is supported by your Linux kernel.
-
- ipaddr - IP address; needed for tftpboot command
-
- loadaddr - Default load address for commands like "bootp",
- "rarpboot", "tftpboot", "loadb" or "diskboot"
-
- loads_echo - see CONFIG_LOADS_ECHO
-
- serverip - TFTP server IP address; needed for tftpboot command
-
- bootretry - see CONFIG_BOOT_RETRY_TIME
-
- bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
-
- bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
-
- ethprime - When CONFIG_NET_MULTI is enabled controls which
- interface is used first.
-
- ethact - When CONFIG_NET_MULTI is enabled controls which
- interface is currently active. For example you
- can do the following
-
- => setenv ethact FEC ETHERNET
- => ping 192.168.0.1 # traffic sent on FEC ETHERNET
- => setenv ethact SCC ETHERNET
- => ping 10.0.0.1 # traffic sent on SCC ETHERNET
-
- netretry - When set to "no" each network operation will
- either succeed or fail without retrying.
- When set to "once" the network operation will
- fail when all the available network interfaces
- are tried once without success.
- Useful on scripts which control the retry operation
- themselves.
-
- tftpsrcport - If this is set, the value is used for TFTP's
- UDP source port.
-
- tftpdstport - If this is set, the value is used for TFTP's UDP
- destination port instead of the Well Know Port 69.
-
- vlan - When set to a value < 4095 the traffic over
- ethernet is encapsulated/received over 802.1q
- VLAN tagged frames.
-
-The following environment variables may be used and automatically
-updated by the network boot commands ("bootp" and "rarpboot"),
-depending the information provided by your boot server:
-
- bootfile - see above
- dnsip - IP address of your Domain Name Server
- dnsip2 - IP address of your secondary Domain Name Server
- gatewayip - IP address of the Gateway (Router) to use
- hostname - Target hostname
- ipaddr - see above
- netmask - Subnet Mask
- rootpath - Pathname of the root filesystem on the NFS server
- serverip - see above
-
-
-There are two special Environment Variables:
-
- serial# - contains hardware identification information such
- as type string and/or serial number
- ethaddr - Ethernet address
-
-These variables can be set only once (usually during manufacturing of
-the board). U-Boot refuses to delete or overwrite these variables
-once they have been set once.
-
-
-Further special Environment Variables:
-
- ver - Contains the U-Boot version string as printed
- with the "version" command. This variable is
- readonly (see CONFIG_VERSION_VARIABLE).
-
-
-Please note that changes to some configuration parameters may take
-only effect after the next boot (yes, that's just like Windoze :-).
-
-
-Command Line Parsing:
-=====================
-
-There are two different command line parsers available with U-Boot:
-the old "simple" one, and the much more powerful "hush" shell:
-
-Old, simple command line parser:
---------------------------------
-
-- supports environment variables (through setenv / saveenv commands)
-- several commands on one line, separated by ';'
-- variable substitution using "... ${name} ..." syntax
-- special characters ('$', ';') can be escaped by prefixing with '\',
- for example:
- setenv bootcmd bootm \${address}
-- You can also escape text by enclosing in single apostrophes, for example:
- setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
-
-Hush shell:
------------
-
-- similar to Bourne shell, with control structures like
- if...then...else...fi, for...do...done; while...do...done,
- until...do...done, ...
-- supports environment ("global") variables (through setenv / saveenv
- commands) and local shell variables (through standard shell syntax
- "name=value"); only environment variables can be used with "run"
- command
-
-General rules:
---------------
-
-(1) If a command line (or an environment variable executed by a "run"
- command) contains several commands separated by semicolon, and
- one of these commands fails, then the remaining commands will be
- executed anyway.
-
-(2) If you execute several variables with one call to run (i. e.
- calling run with a list af variables as arguments), any failing
- command will cause "run" to terminate, i. e. the remaining
- variables are not executed.
-
-Note for Redundant Ethernet Interfaces:
-=======================================
-
-Some boards come with redundant ethernet interfaces; U-Boot supports
-such configurations and is capable of automatic selection of a
-"working" interface when needed. MAC assignment works as follows:
-
-Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
-MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
-"eth1addr" (=>eth1), "eth2addr", ...
-
-If the network interface stores some valid MAC address (for instance
-in SROM), this is used as default address if there is NO correspon-
-ding setting in the environment; if the corresponding environment
-variable is set, this overrides the settings in the card; that means:
-
-o If the SROM has a valid MAC address, and there is no address in the
- environment, the SROM's address is used.
-
-o If there is no valid address in the SROM, and a definition in the
- environment exists, then the value from the environment variable is
- used.
-
-o If both the SROM and the environment contain a MAC address, and
- both addresses are the same, this MAC address is used.
-
-o If both the SROM and the environment contain a MAC address, and the
- addresses differ, the value from the environment is used and a
- warning is printed.
-
-o If neither SROM nor the environment contain a MAC address, an error
- is raised.
-
-
-Image Formats:
-==============
-
-The "boot" commands of this monitor operate on "image" files which
-can be basicly anything, preceeded by a special header; see the
-definitions in include/image.h for details; basicly, the header
-defines the following image properties:
-
-* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
- 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
- LynxOS, pSOS, QNX, RTEMS, ARTOS;
- Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
-* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
- IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
- Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
-* Compression Type (uncompressed, gzip, bzip2)
-* Load Address
-* Entry Point
-* Image Name
-* Image Timestamp
-
-The header is marked by a special Magic Number, and both the header
-and the data portions of the image are secured against corruption by
-CRC32 checksums.
-
-
-Linux Support:
-==============
-
-Although U-Boot should support any OS or standalone application
-easily, the main focus has always been on Linux during the design of
-U-Boot.
-
-U-Boot includes many features that so far have been part of some
-special "boot loader" code within the Linux kernel. Also, any
-"initrd" images to be used are no longer part of one big Linux image;
-instead, kernel and "initrd" are separate images. This implementation
-serves several purposes:
-
-- the same features can be used for other OS or standalone
- applications (for instance: using compressed images to reduce the
- Flash memory footprint)
-
-- it becomes much easier to port new Linux kernel versions because
- lots of low-level, hardware dependent stuff are done by U-Boot
-
-- the same Linux kernel image can now be used with different "initrd"
- images; of course this also means that different kernel images can
- be run with the same "initrd". This makes testing easier (you don't
- have to build a new "zImage.initrd" Linux image when you just
- change a file in your "initrd"). Also, a field-upgrade of the
- software is easier now.
-
-
-Linux HOWTO:
-============
-
-Porting Linux to U-Boot based systems:
----------------------------------------
-
-U-Boot cannot save you from doing all the necessary modifications to
-configure the Linux device drivers for use with your target hardware
-(no, we don't intend to provide a full virtual machine interface to
-Linux :-).
-
-But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
-
-Just make sure your machine specific header file (for instance
-include/asm-ppc/tqm8xx.h) includes the same definition of the Board
-Information structure as we define in include/u-boot.h, and make
-sure that your definition of IMAP_ADDR uses the same value as your
-U-Boot configuration in CFG_IMMR.
-
-
-Configuring the Linux kernel:
------------------------------
-
-No specific requirements for U-Boot. Make sure you have some root
-device (initial ramdisk, NFS) for your target system.
-
-
-Building a Linux Image:
------------------------
-
-With U-Boot, "normal" build targets like "zImage" or "bzImage" are
-not used. If you use recent kernel source, a new build target
-"uImage" will exist which automatically builds an image usable by
-U-Boot. Most older kernels also have support for a "pImage" target,
-which was introduced for our predecessor project PPCBoot and uses a
-100% compatible format.
-
-Example:
-
- make TQM850L_config
- make oldconfig
- make dep
- make uImage
-
-The "uImage" build target uses a special tool (in 'tools/mkimage') to
-encapsulate a compressed Linux kernel image with header information,
-CRC32 checksum etc. for use with U-Boot. This is what we are doing:
-
-* build a standard "vmlinux" kernel image (in ELF binary format):
-
-* convert the kernel into a raw binary image:
-
- ${CROSS_COMPILE}-objcopy -O binary \
- -R .note -R .comment \
- -S vmlinux linux.bin
-
-* compress the binary image:
-
- gzip -9 linux.bin
-
-* package compressed binary image for U-Boot:
-
- mkimage -A ppc -O linux -T kernel -C gzip \
- -a 0 -e 0 -n "Linux Kernel Image" \
- -d linux.bin.gz uImage
-
-
-The "mkimage" tool can also be used to create ramdisk images for use
-with U-Boot, either separated from the Linux kernel image, or
-combined into one file. "mkimage" encapsulates the images with a 64
-byte header containing information about target architecture,
-operating system, image type, compression method, entry points, time
-stamp, CRC32 checksums, etc.
-
-"mkimage" can be called in two ways: to verify existing images and
-print the header information, or to build new images.
-
-In the first form (with "-l" option) mkimage lists the information
-contained in the header of an existing U-Boot image; this includes
-checksum verification:
-
- tools/mkimage -l image
- -l ==> list image header information
-
-The second form (with "-d" option) is used to build a U-Boot image
-from a "data file" which is used as image payload:
-
- tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
- -n name -d data_file image
- -A ==> set architecture to 'arch'
- -O ==> set operating system to 'os'
- -T ==> set image type to 'type'
- -C ==> set compression type 'comp'
- -a ==> set load address to 'addr' (hex)
- -e ==> set entry point to 'ep' (hex)
- -n ==> set image name to 'name'
- -d ==> use image data from 'datafile'
-
-Right now, all Linux kernels for PowerPC systems use the same load
-address (0x00000000), but the entry point address depends on the
-kernel version:
-
-- 2.2.x kernels have the entry point at 0x0000000C,
-- 2.3.x and later kernels have the entry point at 0x00000000.
-
-So a typical call to build a U-Boot image would read:
-
- -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
- > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
- > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
- > examples/uImage.TQM850L
- Image Name: 2.4.4 kernel for TQM850L
- Created: Wed Jul 19 02:34:59 2000
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
- Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
- Load Address: 0x00000000
- Entry Point: 0x00000000
-
-To verify the contents of the image (or check for corruption):
-
- -> tools/mkimage -l examples/uImage.TQM850L
- Image Name: 2.4.4 kernel for TQM850L
- Created: Wed Jul 19 02:34:59 2000
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
- Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
- Load Address: 0x00000000
- Entry Point: 0x00000000
-
-NOTE: for embedded systems where boot time is critical you can trade
-speed for memory and install an UNCOMPRESSED image instead: this
-needs more space in Flash, but boots much faster since it does not
-need to be uncompressed:
-
- -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
- -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
- > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
- > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
- > examples/uImage.TQM850L-uncompressed
- Image Name: 2.4.4 kernel for TQM850L
- Created: Wed Jul 19 02:34:59 2000
- Image Type: PowerPC Linux Kernel Image (uncompressed)
- Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
- Load Address: 0x00000000
- Entry Point: 0x00000000
-
-
-Similar you can build U-Boot images from a 'ramdisk.image.gz' file
-when your kernel is intended to use an initial ramdisk:
-
- -> tools/mkimage -n 'Simple Ramdisk Image' \
- > -A ppc -O linux -T ramdisk -C gzip \
- > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
- Image Name: Simple Ramdisk Image
- Created: Wed Jan 12 14:01:50 2000
- Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
- Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
- Load Address: 0x00000000
- Entry Point: 0x00000000
-
-
-Installing a Linux Image:
--------------------------
-
-To downloading a U-Boot image over the serial (console) interface,
-you must convert the image to S-Record format:
-
- objcopy -I binary -O srec examples/image examples/image.srec
-
-The 'objcopy' does not understand the information in the U-Boot
-image header, so the resulting S-Record file will be relative to
-address 0x00000000. To load it to a given address, you need to
-specify the target address as 'offset' parameter with the 'loads'
-command.
-
-Example: install the image to address 0x40100000 (which on the
-TQM8xxL is in the first Flash bank):
-
- => erase 40100000 401FFFFF
-
- .......... done
- Erased 8 sectors
-
- => loads 40100000
- ## Ready for S-Record download ...
- ~>examples/image.srec
- 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
- ...
- 15989 15990 15991 15992
- [file transfer complete]
- [connected]
- ## Start Addr = 0x00000000
-
-
-You can check the success of the download using the 'iminfo' command;
-this includes a checksum verification so you can be sure no data
-corruption happened:
-
- => imi 40100000
-
- ## Checking Image at 40100000 ...
- Image Name: 2.2.13 for initrd on TQM850L
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
- Data Size: 335725 Bytes = 327 kB = 0 MB
- Load Address: 00000000
- Entry Point: 0000000c
- Verifying Checksum ... OK
-
-
-Boot Linux:
------------
-
-The "bootm" command is used to boot an application that is stored in
-memory (RAM or Flash). In case of a Linux kernel image, the contents
-of the "bootargs" environment variable is passed to the kernel as
-parameters. You can check and modify this variable using the
-"printenv" and "setenv" commands:
-
-
- => printenv bootargs
- bootargs=root=/dev/ram
-
- => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
-
- => printenv bootargs
- bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
-
- => bootm 40020000
- ## Booting Linux kernel at 40020000 ...
- Image Name: 2.2.13 for NFS on TQM850L
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
- Data Size: 381681 Bytes = 372 kB = 0 MB
- Load Address: 00000000
- Entry Point: 0000000c
- Verifying Checksum ... OK
- Uncompressing Kernel Image ... OK
- Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
- Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
- time_init: decrementer frequency = 187500000/60
- Calibrating delay loop... 49.77 BogoMIPS
- Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
- ...
-
-If you want to boot a Linux kernel with initial ram disk, you pass
-the memory addresses of both the kernel and the initrd image (PPBCOOT
-format!) to the "bootm" command:
-
- => imi 40100000 40200000
-
- ## Checking Image at 40100000 ...
- Image Name: 2.2.13 for initrd on TQM850L
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
- Data Size: 335725 Bytes = 327 kB = 0 MB
- Load Address: 00000000
- Entry Point: 0000000c
- Verifying Checksum ... OK
-
- ## Checking Image at 40200000 ...
- Image Name: Simple Ramdisk Image
- Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
- Data Size: 566530 Bytes = 553 kB = 0 MB
- Load Address: 00000000
- Entry Point: 00000000
- Verifying Checksum ... OK
-
- => bootm 40100000 40200000
- ## Booting Linux kernel at 40100000 ...
- Image Name: 2.2.13 for initrd on TQM850L
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
- Data Size: 335725 Bytes = 327 kB = 0 MB
- Load Address: 00000000
- Entry Point: 0000000c
- Verifying Checksum ... OK
- Uncompressing Kernel Image ... OK
- ## Loading RAMDisk Image at 40200000 ...
- Image Name: Simple Ramdisk Image
- Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
- Data Size: 566530 Bytes = 553 kB = 0 MB
- Load Address: 00000000
- Entry Point: 00000000
- Verifying Checksum ... OK
- Loading Ramdisk ... OK
- Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
- Boot arguments: root=/dev/ram
- time_init: decrementer frequency = 187500000/60
- Calibrating delay loop... 49.77 BogoMIPS
- ...
- RAMDISK: Compressed image found at block 0
- VFS: Mounted root (ext2 filesystem).
-
- bash#
-
-Boot Linux and pass a flat device tree:
------------
-
-First, U-Boot must be compiled with the appropriate defines. See the section
-titled "Linux Kernel Interface" above for a more in depth explanation. The
-following is an example of how to start a kernel and pass an updated
-flat device tree:
-
-=> print oftaddr
-oftaddr=0x300000
-=> print oft
-oft=oftrees/mpc8540ads.dtb
-=> tftp $oftaddr $oft
-Speed: 1000, full duplex
-Using TSEC0 device
-TFTP from server 192.168.1.1; our IP address is 192.168.1.101
-Filename 'oftrees/mpc8540ads.dtb'.
-Load address: 0x300000
-Loading: #
-done
-Bytes transferred = 4106 (100a hex)
-=> tftp $loadaddr $bootfile
-Speed: 1000, full duplex
-Using TSEC0 device
-TFTP from server 192.168.1.1; our IP address is 192.168.1.2
-Filename 'uImage'.
-Load address: 0x200000
-Loading:############
-done
-Bytes transferred = 1029407 (fb51f hex)
-=> print loadaddr
-loadaddr=200000
-=> print oftaddr
-oftaddr=0x300000
-=> bootm $loadaddr - $oftaddr
-## Booting image at 00200000 ...
- Image Name: Linux-2.6.17-dirty
- Image Type: PowerPC Linux Kernel Image (gzip compressed)
- Data Size: 1029343 Bytes = 1005.2 kB
- Load Address: 00000000
- Entry Point: 00000000
- Verifying Checksum ... OK
- Uncompressing Kernel Image ... OK
-Booting using flat device tree at 0x300000
-Using MPC85xx ADS machine description
-Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
-[snip]
-
-
-More About U-Boot Image Types:
-------------------------------
-
-U-Boot supports the following image types:
-
- "Standalone Programs" are directly runnable in the environment
- provided by U-Boot; it is expected that (if they behave
- well) you can continue to work in U-Boot after return from
- the Standalone Program.
- "OS Kernel Images" are usually images of some Embedded OS which
- will take over control completely. Usually these programs
- will install their own set of exception handlers, device
- drivers, set up the MMU, etc. - this means, that you cannot
- expect to re-enter U-Boot except by resetting the CPU.
- "RAMDisk Images" are more or less just data blocks, and their
- parameters (address, size) are passed to an OS kernel that is
- being started.
- "Multi-File Images" contain several images, typically an OS
- (Linux) kernel image and one or more data images like
- RAMDisks. This construct is useful for instance when you want
- to boot over the network using BOOTP etc., where the boot
- server provides just a single image file, but you want to get
- for instance an OS kernel and a RAMDisk image.
-
- "Multi-File Images" start with a list of image sizes, each
- image size (in bytes) specified by an "uint32_t" in network
- byte order. This list is terminated by an "(uint32_t)0".
- Immediately after the terminating 0 follow the images, one by
- one, all aligned on "uint32_t" boundaries (size rounded up to
- a multiple of 4 bytes).
-
- "Firmware Images" are binary images containing firmware (like
- U-Boot or FPGA images) which usually will be programmed to
- flash memory.
-
- "Script files" are command sequences that will be executed by
- U-Boot's command interpreter; this feature is especially
- useful when you configure U-Boot to use a real shell (hush)
- as command interpreter.
-
-
-Standalone HOWTO:
-=================
-
-One of the features of U-Boot is that you can dynamically load and
-run "standalone" applications, which can use some resources of
-U-Boot like console I/O functions or interrupt services.
-
-Two simple examples are included with the sources:
-
-"Hello World" Demo:
--------------------
-
-'examples/hello_world.c' contains a small "Hello World" Demo
-application; it is automatically compiled when you build U-Boot.
-It's configured to run at address 0x00040004, so you can play with it
-like that:
-
- => loads
- ## Ready for S-Record download ...
- ~>examples/hello_world.srec
- 1 2 3 4 5 6 7 8 9 10 11 ...
- [file transfer complete]
- [connected]
- ## Start Addr = 0x00040004
-
- => go 40004 Hello World! This is a test.
- ## Starting application at 0x00040004 ...
- Hello World
- argc = 7
- argv[0] = "40004"
- argv[1] = "Hello"
- argv[2] = "World!"
- argv[3] = "This"
- argv[4] = "is"
- argv[5] = "a"
- argv[6] = "test."
- argv[7] = "<NULL>"
- Hit any key to exit ...
-
- ## Application terminated, rc = 0x0
-
-Another example, which demonstrates how to register a CPM interrupt
-handler with the U-Boot code, can be found in 'examples/timer.c'.
-Here, a CPM timer is set up to generate an interrupt every second.
-The interrupt service routine is trivial, just printing a '.'
-character, but this is just a demo program. The application can be
-controlled by the following keys:
-
- ? - print current values og the CPM Timer registers
- b - enable interrupts and start timer
- e - stop timer and disable interrupts
- q - quit application
-
- => loads
- ## Ready for S-Record download ...
- ~>examples/timer.srec
- 1 2 3 4 5 6 7 8 9 10 11 ...
- [file transfer complete]
- [connected]
- ## Start Addr = 0x00040004
-
- => go 40004
- ## Starting application at 0x00040004 ...
- TIMERS=0xfff00980
- Using timer 1
- tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
-
-Hit 'b':
- [q, b, e, ?] Set interval 1000000 us
- Enabling timer
-Hit '?':
- [q, b, e, ?] ........
- tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
-Hit '?':
- [q, b, e, ?] .
- tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
-Hit '?':
- [q, b, e, ?] .
- tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
-Hit '?':
- [q, b, e, ?] .
- tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
-Hit 'e':
- [q, b, e, ?] ...Stopping timer
-Hit 'q':
- [q, b, e, ?] ## Application terminated, rc = 0x0
-
-
-Minicom warning:
-================
-
-Over time, many people have reported problems when trying to use the
-"minicom" terminal emulation program for serial download. I (wd)
-consider minicom to be broken, and recommend not to use it. Under
-Unix, I recommend to use C-Kermit for general purpose use (and
-especially for kermit binary protocol download ("loadb" command), and
-use "cu" for S-Record download ("loads" command).
-
-Nevertheless, if you absolutely want to use it try adding this
-configuration to your "File transfer protocols" section:
-
- Name Program Name U/D FullScr IO-Red. Multi
- X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
- Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
-
-
-NetBSD Notes:
-=============
-
-Starting at version 0.9.2, U-Boot supports NetBSD both as host
-(build U-Boot) and target system (boots NetBSD/mpc8xx).
-
-Building requires a cross environment; it is known to work on
-NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
-need gmake since the Makefiles are not compatible with BSD make).
-Note that the cross-powerpc package does not install include files;
-attempting to build U-Boot will fail because <machine/ansi.h> is
-missing. This file has to be installed and patched manually:
-
- # cd /usr/pkg/cross/powerpc-netbsd/include
- # mkdir powerpc
- # ln -s powerpc machine
- # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
- # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
-
-Native builds *don't* work due to incompatibilities between native
-and U-Boot include files.
-
-Booting assumes that (the first part of) the image booted is a
-stage-2 loader which in turn loads and then invokes the kernel
-proper. Loader sources will eventually appear in the NetBSD source
-tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
-meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
-
-
-Implementation Internals:
-=========================
-
-The following is not intended to be a complete description of every
-implementation detail. However, it should help to understand the
-inner workings of U-Boot and make it easier to port it to custom
-hardware.
-
-
-Initial Stack, Global Data:
----------------------------
-
-The implementation of U-Boot is complicated by the fact that U-Boot
-starts running out of ROM (flash memory), usually without access to
-system RAM (because the memory controller is not initialized yet).
-This means that we don't have writable Data or BSS segments, and BSS
-is not initialized as zero. To be able to get a C environment working
-at all, we have to allocate at least a minimal stack. Implementation
-options for this are defined and restricted by the CPU used: Some CPU
-models provide on-chip memory (like the IMMR area on MPC8xx and
-MPC826x processors), on others (parts of) the data cache can be
-locked as (mis-) used as memory, etc.
-
- Chris Hallinan posted a good summary of these issues to the
- u-boot-users mailing list:
-
- Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
- From: "Chris Hallinan" <clh@net1plus.com>
- Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
- ...
-
- Correct me if I'm wrong, folks, but the way I understand it
- is this: Using DCACHE as initial RAM for Stack, etc, does not
- require any physical RAM backing up the cache. The cleverness
- is that the cache is being used as a temporary supply of
- necessary storage before the SDRAM controller is setup. It's
- beyond the scope of this list to expain the details, but you
- can see how this works by studying the cache architecture and
- operation in the architecture and processor-specific manuals.
-
- OCM is On Chip Memory, which I believe the 405GP has 4K. It
- is another option for the system designer to use as an
- initial stack/ram area prior to SDRAM being available. Either
- option should work for you. Using CS 4 should be fine if your
- board designers haven't used it for something that would
- cause you grief during the initial boot! It is frequently not
- used.
-
- CFG_INIT_RAM_ADDR should be somewhere that won't interfere
- with your processor/board/system design. The default value
- you will find in any recent u-boot distribution in
- walnut.h should work for you. I'd set it to a value larger
- than your SDRAM module. If you have a 64MB SDRAM module, set
- it above 400_0000. Just make sure your board has no resources
- that are supposed to respond to that address! That code in
- start.S has been around a while and should work as is when
- you get the config right.
-
- -Chris Hallinan
- DS4.COM, Inc.
-
-It is essential to remember this, since it has some impact on the C
-code for the initialization procedures:
-
-* Initialized global data (data segment) is read-only. Do not attempt
- to write it.
-
-* Do not use any unitialized global data (or implicitely initialized
- as zero data - BSS segment) at all - this is undefined, initiali-
- zation is performed later (when relocating to RAM).
-
-* Stack space is very limited. Avoid big data buffers or things like
- that.
-
-Having only the stack as writable memory limits means we cannot use
-normal global data to share information beween the code. But it
-turned out that the implementation of U-Boot can be greatly
-simplified by making a global data structure (gd_t) available to all
-functions. We could pass a pointer to this data as argument to _all_
-functions, but this would bloat the code. Instead we use a feature of
-the GCC compiler (Global Register Variables) to share the data: we
-place a pointer (gd) to the global data into a register which we
-reserve for this purpose.
-
-When choosing a register for such a purpose we are restricted by the
-relevant (E)ABI specifications for the current architecture, and by
-GCC's implementation.
-
-For PowerPC, the following registers have specific use:
- R1: stack pointer
- R2: TOC pointer
- R3-R4: parameter passing and return values
- R5-R10: parameter passing
- R13: small data area pointer
- R30: GOT pointer
- R31: frame pointer
-
- (U-Boot also uses R14 as internal GOT pointer.)
-
- ==> U-Boot will use R29 to hold a pointer to the global data
-
- Note: on PPC, we could use a static initializer (since the
- address of the global data structure is known at compile time),
- but it turned out that reserving a register results in somewhat
- smaller code - although the code savings are not that big (on
- average for all boards 752 bytes for the whole U-Boot image,
- 624 text + 127 data).
-
-On ARM, the following registers are used:
-
- R0: function argument word/integer result
- R1-R3: function argument word
- R9: GOT pointer
- R10: stack limit (used only if stack checking if enabled)
- R11: argument (frame) pointer
- R12: temporary workspace
- R13: stack pointer
- R14: link register
- R15: program counter
-
- ==> U-Boot will use R8 to hold a pointer to the global data
-
-NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
-or current versions of GCC may "optimize" the code too much.
-
-Memory Management:
-------------------
-
-U-Boot runs in system state and uses physical addresses, i.e. the
-MMU is not used either for address mapping nor for memory protection.
-
-The available memory is mapped to fixed addresses using the memory
-controller. In this process, a contiguous block is formed for each
-memory type (Flash, SDRAM, SRAM), even when it consists of several
-physical memory banks.
-
-U-Boot is installed in the first 128 kB of the first Flash bank (on
-TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
-booting and sizing and initializing DRAM, the code relocates itself
-to the upper end of DRAM. Immediately below the U-Boot code some
-memory is reserved for use by malloc() [see CFG_MALLOC_LEN
-configuration setting]. Below that, a structure with global Board
-Info data is placed, followed by the stack (growing downward).
-
-Additionally, some exception handler code is copied to the low 8 kB
-of DRAM (0x00000000 ... 0x00001FFF).
-
-So a typical memory configuration with 16 MB of DRAM could look like
-this:
-
- 0x0000 0000 Exception Vector code
- :
- 0x0000 1FFF
- 0x0000 2000 Free for Application Use
- :
- :
-
- :
- :
- 0x00FB FF20 Monitor Stack (Growing downward)
- 0x00FB FFAC Board Info Data and permanent copy of global data
- 0x00FC 0000 Malloc Arena
- :
- 0x00FD FFFF
- 0x00FE 0000 RAM Copy of Monitor Code
- ... eventually: LCD or video framebuffer
- ... eventually: pRAM (Protected RAM - unchanged by reset)
- 0x00FF FFFF [End of RAM]
-
-
-System Initialization:
-----------------------
-
-In the reset configuration, U-Boot starts at the reset entry point
-(on most PowerPC systens at address 0x00000100). Because of the reset
-configuration for CS0# this is a mirror of the onboard Flash memory.
-To be able to re-map memory U-Boot then jumps to its link address.
-To be able to implement the initialization code in C, a (small!)
-initial stack is set up in the internal Dual Ported RAM (in case CPUs
-which provide such a feature like MPC8xx or MPC8260), or in a locked
-part of the data cache. After that, U-Boot initializes the CPU core,
-the caches and the SIU.
-
-Next, all (potentially) available memory banks are mapped using a
-preliminary mapping. For example, we put them on 512 MB boundaries
-(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
-on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
-programmed for SDRAM access. Using the temporary configuration, a
-simple memory test is run that determines the size of the SDRAM
-banks.
-
-When there is more than one SDRAM bank, and the banks are of
-different size, the largest is mapped first. For equal size, the first
-bank (CS2#) is mapped first. The first mapping is always for address
-0x00000000, with any additional banks following immediately to create
-contiguous memory starting from 0.
-
-Then, the monitor installs itself at the upper end of the SDRAM area
-and allocates memory for use by malloc() and for the global Board
-Info data; also, the exception vector code is copied to the low RAM
-pages, and the final stack is set up.
-
-Only after this relocation will you have a "normal" C environment;
-until that you are restricted in several ways, mostly because you are
-running from ROM, and because the code will have to be relocated to a
-new address in RAM.
-
-
-U-Boot Porting Guide:
-----------------------
-
-[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
-list, October 2002]
-
-
-int main (int argc, char *argv[])
-{
- sighandler_t no_more_time;
-
- signal (SIGALRM, no_more_time);
- alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
-
- if (available_money > available_manpower) {
- pay consultant to port U-Boot;
- return 0;
- }
-
- Download latest U-Boot source;
-
- Subscribe to u-boot-users mailing list;
-
- if (clueless) {
- email ("Hi, I am new to U-Boot, how do I get started?");
- }
-
- while (learning) {
- Read the README file in the top level directory;
- Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
- Read the source, Luke;
- }
-
- if (available_money > toLocalCurrency ($2500)) {
- Buy a BDI2000;
- } else {
- Add a lot of aggravation and time;
- }
-
- Create your own board support subdirectory;
-
- Create your own board config file;
-
- while (!running) {
- do {
- Add / modify source code;
- } until (compiles);
- Debug;
- if (clueless)
- email ("Hi, I am having problems...");
- }
- Send patch file to Wolfgang;
-
- return 0;
-}
-
-void no_more_time (int sig)
-{
- hire_a_guru();
-}
-
-
-Coding Standards:
------------------
-
-All contributions to U-Boot should conform to the Linux kernel
-coding style; see the file "Documentation/CodingStyle" and the script
-"scripts/Lindent" in your Linux kernel source directory. In sources
-originating from U-Boot a style corresponding to "Lindent -pcs" (adding
-spaces before parameters to function calls) is actually used.
-
-Source files originating from a different project (for example the
-MTD subsystem) are generally exempt from these guidelines and are not
-reformated to ease subsequent migration to newer versions of those
-sources.
-
-Please note that U-Boot is implemented in C (and to some small parts in
-Assembler); no C++ is used, so please do not use C++ style comments (//)
-in your code.
-
-Please also stick to the following formatting rules:
-- remove any trailing white space
-- use TAB characters for indentation, not spaces
-- make sure NOT to use DOS '\r\n' line feeds
-- do not add more than 2 empty lines to source files
-- do not add trailing empty lines to source files
-
-Submissions which do not conform to the standards may be returned
-with a request to reformat the changes.
-
-
-Submitting Patches:
--------------------
-
-Since the number of patches for U-Boot is growing, we need to
-establish some rules. Submissions which do not conform to these rules
-may be rejected, even when they contain important and valuable stuff.
-
-Patches shall be sent to the u-boot-users mailing list.
-
-When you send a patch, please include the following information with
-it:
-
-* For bug fixes: a description of the bug and how your patch fixes
- this bug. Please try to include a way of demonstrating that the
- patch actually fixes something.
-
-* For new features: a description of the feature and your
- implementation.
-
-* A CHANGELOG entry as plaintext (separate from the patch)
-
-* For major contributions, your entry to the CREDITS file
-
-* When you add support for a new board, don't forget to add this
- board to the MAKEALL script, too.
-
-* If your patch adds new configuration options, don't forget to
- document these in the README file.
-
-* The patch itself. If you are accessing the CVS repository use "cvs
- update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
- version of diff does not support these options, then get the latest
- version of GNU diff.
-
- The current directory when running this command shall be the top
- level directory of the U-Boot source tree, or it's parent directory
- (i. e. please make sure that your patch includes sufficient
- directory information for the affected files).
-
- We accept patches as plain text, MIME attachments or as uuencoded
- gzipped text.
-
-* If one logical set of modifications affects or creates several
- files, all these changes shall be submitted in a SINGLE patch file.
-
-* Changesets that contain different, unrelated modifications shall be
- submitted as SEPARATE patches, one patch per changeset.
-
-
-Notes:
-
-* Before sending the patch, run the MAKEALL script on your patched
- source tree and make sure that no errors or warnings are reported
- for any of the boards.
-
-* Keep your modifications to the necessary minimum: A patch
- containing several unrelated changes or arbitrary reformats will be
- returned with a request to re-formatting / split it.
-
-* If you modify existing code, make sure that your new code does not
- add to the memory footprint of the code ;-) Small is beautiful!
- When adding new features, these should compile conditionally only
- (using #ifdef), and the resulting code with the new feature
- disabled must not need more memory than the old code without your
- modification.
-
-* Remember that there is a size limit of 40 kB per message on the
- u-boot-users mailing list. Compression may help.