diff options
Diffstat (limited to 'arch/cris/boot/compressed/head_v10.S')
| -rw-r--r-- | arch/cris/boot/compressed/head_v10.S | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/arch/cris/boot/compressed/head_v10.S b/arch/cris/boot/compressed/head_v10.S new file mode 100644 index 00000000000..9edb8ade7e1 --- /dev/null +++ b/arch/cris/boot/compressed/head_v10.S @@ -0,0 +1,126 @@ +/* + * arch/cris/boot/compressed/head.S + * + * Copyright (C) 1999, 2001 Axis Communications AB + * + * Code that sets up the DRAM registers, calls the + * decompressor to unpack the piggybacked kernel, and jumps. + * + */ + +#define ASSEMBLER_MACROS_ONLY +#include <arch/sv_addr_ag.h> + +#define RAM_INIT_MAGIC 0x56902387 +#define COMMAND_LINE_MAGIC 0x87109563 + + ;; Exported symbols + + .globl input_data + + + .text + + nop + di + +;; We need to initialze DRAM registers before we start using the DRAM + + cmp.d RAM_INIT_MAGIC, $r8 ; Already initialized? + beq dram_init_finished + nop + +#include "../../arch-v10/lib/dram_init.S" + +dram_init_finished: + + ;; Initiate the PA and PB ports + + move.b CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r0 + move.b $r0, [R_PORT_PA_DATA] + + move.b CONFIG_ETRAX_DEF_R_PORT_PA_DIR, $r0 + move.b $r0, [R_PORT_PA_DIR] + + move.b CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r0 + move.b $r0, [R_PORT_PB_DATA] + + move.b CONFIG_ETRAX_DEF_R_PORT_PB_DIR, $r0 + move.b $r0, [R_PORT_PB_DIR] + + ;; Setup the stack to a suitably high address. + ;; We assume 8 MB is the minimum DRAM in an eLinux + ;; product and put the sp at the top for now. + + move.d 0x40800000, $sp + + ;; Figure out where the compressed piggyback image is + ;; in the flash (since we wont try to copy it to DRAM + ;; before unpacking). It is at _edata, but in flash. + ;; Use (_edata - basse) as offset to the current PC. + +basse: move.d $pc, $r5 + and.d 0x7fffffff, $r5 ; strip any non-cache bit + subq 2, $r5 ; compensate for the move.d $pc instr + move.d $r5, $r0 ; save for later - flash address of 'basse' + add.d _edata, $r5 + sub.d basse, $r5 ; $r5 = flash address of '_edata' + + ;; Copy text+data to DRAM + + move.d basse, $r1 ; destination + move.d _edata, $r2 ; end destination +1: move.w [$r0+], $r3 + move.w $r3, [$r1+] + cmp.d $r2, $r1 + bcs 1b + nop + + move.d $r5, [input_data] ; 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, $r12 + move.d $r10, [$r12] + move.d _cmd_line_addr, $r12 + move.d $r11, [$r12] + + ;; Do the decompression and save compressed size in inptr + + jsr decompress_kernel + + ;; Put start address of root partition in $r9 so the kernel can use it + ;; when mounting from flash + + move.d [input_data], $r9 ; flash address of compressed kernel + add.d [inptr], $r9 ; size of compressed kernel + + ;; 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 + + ;; Enter the decompressed kernel + move.d RAM_INIT_MAGIC, $r8 ; Tell kernel that DRAM is initialized + jump 0x40004000 ; kernel is linked to this address + + .data + +input_data: + .dword 0 ; used by the decompressor +_cmd_line_magic: + .dword 0 +_cmd_line_addr: + .dword 0 +#include "../../arch-v10/lib/hw_settings.S" |