| /* |
| * 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. |
| * |
| */ |
| |
| #include <linux/config.h> |
| #define ASSEMBLER_MACROS_ONLY |
| #include <asm/arch/sv_addr_ag.h> |
| |
| #define RAM_INIT_MAGIC 0x56902387 |
| |
| ;; 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 "../../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 |
| |
| ;; 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 |
| |
| ;; 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 |
| |
| #include "../../lib/hw_settings.S" |
