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Diffstat (limited to 'arch/architecture.dox')
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diff --git a/arch/architecture.dox b/arch/architecture.dox deleted file mode 100644 index 2d2cf05aa7..0000000000 --- a/arch/architecture.dox +++ /dev/null @@ -1,175 +0,0 @@ -/** @page dev_architecture Integrate a new architecture (ARCH) - -@section linker_scripts Rules for the generic Linker Script File - -Never include an object file by name directly! Linker Script Files defines the -layout, not the content. Content is defined in objecfiles instead. - -Don't rely on the given object file order to create your binary @a barebox! This -may work, but is not relyable in all cases (and its a very bad style)! - -For the special case some layout contraints exists, use specific section -naming instead. Refer @ref reset_code how to define this specific section. - -@section reset_code Bring it up: The Reset Code - -The way a CPU wakes up after reset is very specific to its architecture. - -For example the ARM architecture starts its reset code at address 0x0000000, -the x86 architecture at 0x000FFFF0, PowerPC at 0x00000100 or 0xFFFFF100. - -So for the special reset code on all architectures it must be located at -architecture specific locations within the binary @a barebox image. - -All reset code uses section ".text_entry" for its localisation within the -binary @a barebox image. Its up to the linker script file to use this section name -to find the right place in whatever environment and @a barebox sizes. - -@code - .section ".text_entry","ax" -@endcode - -@section arch_files List of changes - - - create a new subdirectory in /arch -TODO - -*/ - -/** @page dev_cpu Integrate a new CPU (MACH) - -Features required for every CPU: - - - clocksource - - CPU reset function - -@section time_keeping Time keeping - -In @a barebox we are using the clocksource mechanism from the Linux Kernel. -This makes it fairly easy to add timer functionality for a new board or -architecture. - -Apart from initialization there is only one function to be registerd: -clocksource_read(). This function returns the current value of a free running -counter. Other functions like udelay() and get_time_ns() are derived from this -function. The only thing you have to implement is a clocksource driver and -to register it at runtime. - -@code -static uint64_t mycpu_clocksource_read(void) -{ - TODO -} - -static struct clocksource cs = { - .read = mycpu_clocksource_read, - .mask = 0xffffffff, - .shift = 10, -}; - -.... - init_clock(&cs); -.... -@endcode - -See arch/arm/mach-imx/clocksource.c for an example. clocksource drivers from -the Linux Kernel can be used nearly 1:1, except for the register accesses. - -Note: For clocksources the __lshrdi3 symbol is needed. You can find the -function for your architecture in the Linux Kernel or a libc of your choice. - -@note @a barebox expects an upward counting counter! - -@section reset_function Reset function - -TODO - -@li @subpage dev_arm_mach -@li @subpage dev_bf_mach -@li @subpage dev_mips_mach -@li @subpage dev_ppc_mach -@li @subpage dev_x86_mach - -*/ - -/** @page io_access_functions I/O access functions - -List of functions to be used for hardware register access (I/O). - -@section native_access Native IN/OUT access - -@note Native means: It uses the same endianess than the CPU. - -@subsection single_native_access Single access of various width - -The following functions are intended to be used for a single I/O access. - -To read a byte (8 bit) from a specific I/O address: -@code -uint8_t readb(unsigned long) -@endcode - -To read a word (16 bit) from a specific I/O address: -@code -uint16_t readw(unsigned long) -@endcode - -To read a long word (32 bit) from a specific I/O address: -@code -uint32_t readl(unsigned long) -@endcode - -To write a byte (8 bit) into a specific I/O address: -@code -void writeb(uint8_t val, unsigned long) -@endcode - -To write a word (16 bit) into a specific I/O address: -@code -void writew(uint16_t val, unsigned long) -@endcode - -To write a long word (32 bit) into a specific I/O address: -@code -void writel(uint32_t val, unsigned long) -@endcode - -@subsection string_native_access String native access of various width - -The following functions are intended to be used for string based I/O access. - -To read a string of bytes (8 bit) from one specific I/O address: -@code -void readsb(const void __iomem *addr, void *mem_buffer, int byte_count); -@endcode - -To read a string of words (16 bit) from one specific I/O address: -@code -void readsw(const void __iomem *addr, void *mem_buffer, int word_count); -@endcode - -To read a string of long words (32 bit) from one specific I/O address: -@code -void readsl(const void __iomem *addr, void *mem_buffer, int long_count); -@endcode - -To write a string of bytes (8 bit) to one specific I/O address: -@code -void writesb(void __iomem *addr, const void *mem_buffer, int byte_count); -@endcode - -To write a string of words (16 bit) to one specific I/O address: -@code -void writesw(void __iomem *addr, const void *mem_buffer, int word_count); -@endcode - -To write a string of long words (32 bit) to one specific I/O address: -@code -void writesl(void __iomem *addr, const void *mem_buffer, int long_count); -@endcode - -@section special_access Special IN/OUT access - -TBD - -*/ |