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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2006-09-25 23:32:13 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 08:48:54 -0700
commit5f97f7f9400de47ae837170bb274e90ad3934386 (patch)
tree514451e6dc6b46253293a00035d375e77b1c65ed /arch/avr32/boot/u-boot/head.S
parent53e62d3aaa60590d4a69b4e07c29f448b5151047 (diff)
downloadlinux-5f97f7f9400de47ae837170bb274e90ad3934386.tar.gz
linux-5f97f7f9400de47ae837170bb274e90ad3934386.tar.xz
[PATCH] avr32 architecture
This adds support for the Atmel AVR32 architecture as well as the AT32AP7000 CPU and the AT32STK1000 development board. AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for cost-sensitive embedded applications, with particular emphasis on low power consumption and high code density. The AVR32 architecture is not binary compatible with earlier 8-bit AVR architectures. The AVR32 architecture, including the instruction set, is described by the AVR32 Architecture Manual, available from http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture. It features a 7-stage pipeline, 16KB instruction and data caches and a full Memory Management Unit. It also comes with a large set of integrated peripherals, many of which are shared with the AT91 ARM-based controllers from Atmel. Full data sheet is available from http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf while the CPU core implementation including caches and MMU is documented by the AVR32 AP Technical Reference, available from http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf Information about the AT32STK1000 development board can be found at http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918 including a BSP CD image with an earlier version of this patch, development tools (binaries and source/patches) and a root filesystem image suitable for booting from SD card. Alternatively, there's a preliminary "getting started" guide available at http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links to the sources and patches you will need in order to set up a cross-compiling environment for avr32-linux. This patch, as well as the other patches included with the BSP and the toolchain patches, is actively supported by Atmel Corporation. [dmccr@us.ibm.com: Fix more pxx_page macro locations] [bunk@stusta.de: fix `make defconfig'] Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Dave McCracken <dmccr@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/avr32/boot/u-boot/head.S')
-rw-r--r--arch/avr32/boot/u-boot/head.S60
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/avr32/boot/u-boot/head.S b/arch/avr32/boot/u-boot/head.S
new file mode 100644
index 000000000000..4488fa27fe94
--- /dev/null
+++ b/arch/avr32/boot/u-boot/head.S
@@ -0,0 +1,60 @@
+/*
+ * Startup code for use with the u-boot bootloader.
+ *
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <asm/setup.h>
+
+ /*
+ * The kernel is loaded where we want it to be and all caches
+ * have just been flushed. We get two parameters from u-boot:
+ *
+ * r12 contains a magic number (ATAG_MAGIC)
+ * r11 points to a tag table providing information about
+ * the system.
+ */
+ .section .init.text,"ax"
+ .global _start
+_start:
+ /* Check if the boot loader actually provided a tag table */
+ lddpc r0, magic_number
+ cp.w r12, r0
+ brne no_tag_table
+
+ /* Initialize .bss */
+ lddpc r2, bss_start_addr
+ lddpc r3, end_addr
+ mov r0, 0
+ mov r1, 0
+1: st.d r2++, r0
+ cp r2, r3
+ brlo 1b
+
+ /*
+ * Save the tag table address for later use. This must be done
+ * _after_ .bss has been initialized...
+ */
+ lddpc r0, tag_table_addr
+ st.w r0[0], r11
+
+ /* Jump to loader-independent setup code */
+ rjmp kernel_entry
+
+ .align 2
+magic_number:
+ .long ATAG_MAGIC
+tag_table_addr:
+ .long bootloader_tags
+bss_start_addr:
+ .long __bss_start
+end_addr:
+ .long _end
+
+no_tag_table:
+ sub r12, pc, (. - 2f)
+ bral panic
+2: .asciz "Boot loader didn't provide correct magic number\n"