diff options
Diffstat (limited to 'arch/cris/boot/compressed/head_v32.S')
-rw-r--r-- | arch/cris/boot/compressed/head_v32.S | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/cris/boot/compressed/head_v32.S b/arch/cris/boot/compressed/head_v32.S new file mode 100644 index 0000000..f483005 --- /dev/null +++ b/arch/cris/boot/compressed/head_v32.S @@ -0,0 +1,145 @@ +/* + * Code that sets up the DRAM registers, calls the + * decompressor to unpack the piggybacked kernel, and jumps. + * + * Copyright (C) 1999 - 2006, Axis Communications AB + */ + +#define ASSEMBLER_MACROS_ONLY +#include <hwregs/asm/reg_map_asm.h> +#include <mach/startup.inc> + +#define RAM_INIT_MAGIC 0x56902387 +#define COMMAND_LINE_MAGIC 0x87109563 + + ;; Exported symbols + + .globl input_data + + .text +start: + di + + ;; Start clocks for used blocks. + START_CLOCKS + + ;; Initialize the DRAM registers. + cmp.d RAM_INIT_MAGIC, $r8 ; Already initialized? + beq dram_init_finished + nop + +#if defined CONFIG_ETRAXFS +#include "../../arch-v32/mach-fs/dram_init.S" +#elif defined CONFIG_CRIS_MACH_ARTPEC3 +#include "../../arch-v32/mach-a3/dram_init.S" +#else +#error Only ETRAXFS and ARTPEC-3 supported! +#endif + +dram_init_finished: + + GIO_INIT + ;; Setup the stack to a suitably high address. + ;; We assume 8 MB is the minimum DRAM and put + ;; the SP at the top for now. + + move.d 0x40800000, $sp + + ;; Figure out where the compressed piggyback image is. + ;; It is either in [NOR] flash (we don't want to copy it + ;; to DRAM before unpacking), or copied to DRAM + ;; by the [NAND] flash boot loader. + ;; The piggyback image is at _edata, but relative to where the + ;; image is actually located in memory, not where it is linked + ;; (the decompressor is linked at 0x40700000+ and runs there). + ;; Use (_edata - herami) as offset to the current PC. + +hereami: + lapcq ., $r5 ; get PC + and.d 0x7fffffff, $r5 ; strip any non-cache bit + move.d $r5, $r0 ; source address of 'herami' + add.d _edata, $r5 + sub.d hereami, $r5 ; r5 = flash address of '_edata' + move.d hereami, $r1 ; destination + + ;; Copy text+data to DRAM + + move.d _edata, $r2 ; end destination +1: move.w [$r0+], $r3 ; from herami+ source + move.w $r3, [$r1+] ; to hereami+ destination (linked address) + cmp.d $r2, $r1 ; finish when destination == _edata + bcs 1b + nop + move.d input_data, $r0 ; for the decompressor + move.d $r5, [$r0] ; for the decompressor + + ;; Clear the decompressors BSS (between _edata and _end) + + moveq 0, $r0 + move.d _edata, $r1 + move.d _end, $r2 +1: move.w $r0, [$r1+] + cmp.d $r2, $r1 + bcs 1b + nop + + ;; Save command line magic and address. + move.d _cmd_line_magic, $r0 + move.d $r10, [$r0] + move.d _cmd_line_addr, $r0 + move.d $r11, [$r0] + + ;; Save boot source indicator + move.d _boot_source, $r0 + move.d $r12, [$r0] + + ;; Do the decompression and save compressed size in _inptr + + jsr decompress_kernel + nop + + ;; Restore boot source indicator + move.d _boot_source, $r12 + move.d [$r12], $r12 + + ;; Restore command line magic and address. + move.d _cmd_line_magic, $r10 + move.d [$r10], $r10 + move.d _cmd_line_addr, $r11 + move.d [$r11], $r11 + + ;; Put start address of root partition in r9 so the kernel can use it + ;; when mounting from flash + move.d input_data, $r0 + move.d [$r0], $r9 ; flash address of compressed kernel + move.d inptr, $r0 + add.d [$r0], $r9 ; size of compressed kernel + cmp.d 0x40000000, $r9 ; image in DRAM ? + blo enter_kernel ; no, must be [NOR] flash, jump + nop ; delay slot + and.d 0x001fffff, $r9 ; assume compressed kernel was < 2M + +enter_kernel: + ;; Enter the decompressed kernel + move.d RAM_INIT_MAGIC, $r8 ; Tell kernel that DRAM is initialized + jump 0x40004000 ; kernel is linked to this address + nop + + .data + +input_data: + .dword 0 ; used by the decompressor +_cmd_line_magic: + .dword 0 +_cmd_line_addr: + .dword 0 +_boot_source: + .dword 0 + +#if defined CONFIG_ETRAXFS +#include "../../arch-v32/mach-fs/hw_settings.S" +#elif defined CONFIG_CRIS_MACH_ARTPEC3 +#include "../../arch-v32/mach-a3/hw_settings.S" +#else +#error Only ETRAXFS and ARTPEC-3 supported! +#endif |