diff options
Diffstat (limited to 'arch/cris/arch-v32/boot/compressed/head.S')
| -rw-r--r-- | arch/cris/arch-v32/boot/compressed/head.S | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/boot/compressed/head.S b/arch/cris/arch-v32/boot/compressed/head.S new file mode 100644 index 00000000000..0c55b83b828 --- /dev/null +++ b/arch/cris/arch-v32/boot/compressed/head.S @@ -0,0 +1,193 @@ +/* + * Code that sets up the DRAM registers, calls the + * decompressor to unpack the piggybacked kernel, and jumps. + * + * Copyright (C) 1999 - 2003, Axis Communications AB + */ + +#include <linux/config.h> +#define ASSEMBLER_MACROS_ONLY +#include <asm/arch/hwregs/asm/reg_map_asm.h> +#include <asm/arch/hwregs/asm/gio_defs_asm.h> +#include <asm/arch/hwregs/asm/config_defs_asm.h> + +#define RAM_INIT_MAGIC 0x56902387 +#define COMMAND_LINE_MAGIC 0x87109563 + + ;; Exported symbols + + .globl input_data + + .text +start: + di + + ;; Start clocks for used blocks. + move.d REG_ADDR(config, regi_config, rw_clk_ctrl), $r1 + move.d [$r1], $r0 + or.d REG_STATE(config, rw_clk_ctrl, cpu, yes) | \ + REG_STATE(config, rw_clk_ctrl, bif, yes) | \ + REG_STATE(config, rw_clk_ctrl, fix_io, yes), $r0 + move.d $r0, [$r1] + + ;; If booting from NAND flash we first have to copy some + ;; data from NAND flash to internal RAM to get the code + ;; that initializes the SDRAM. Lets copy 20 KB. This + ;; code executes at 0x38010000 if booting from NAND and + ;; we are guaranted that at least 0x200 bytes are good so + ;; lets start from there. The first 8192 bytes in the nand + ;; flash is spliced with zeroes and is thus 16384 bytes. + move.d 0x38010200, $r10 + move.d 0x14200, $r11 ; Start offset in NAND flash 0x10200 + 16384 + move.d 0x5000, $r12 ; Length of copy + + ;; Before this code the tools add a partitiontable so the PC + ;; has an offset from the linked address. +offset1: + lapcq ., $r13 ; get PC + add.d first_copy_complete-offset1, $r13 + +#include "../../lib/nand_init.S" + +first_copy_complete: + ;; Initialze the DRAM registers. + cmp.d RAM_INIT_MAGIC, $r8 ; Already initialized? + beq dram_init_finished + nop + +#include "../../lib/dram_init.S" + +dram_init_finished: + lapcq ., $r13 ; get PC + add.d second_copy_complete-dram_init_finished, $r13 + + move.d REG_ADDR(config, regi_config, r_bootsel), $r0 + move.d [$r0], $r0 + and.d REG_MASK(config, r_bootsel, boot_mode), $r0 + cmp.d REG_STATE(config, r_bootsel, boot_mode, nand), $r0 + bne second_copy_complete ; No NAND boot + nop + + ;; Copy 2MB from NAND flash to SDRAM (at 2-4MB into the SDRAM) + move.d 0x40204000, $r10 + move.d 0x8000, $r11 + move.d 0x200000, $r12 + ba copy_nand_to_ram + nop +second_copy_complete: + + ;; Initiate the PA port. + move.d CONFIG_ETRAX_DEF_GIO_PA_OUT, $r0 + move.d REG_ADDR(gio, regi_gio, rw_pa_dout), $r1 + move.d $r0, [$r1] + + move.d CONFIG_ETRAX_DEF_GIO_PA_OE, $r0 + move.d REG_ADDR(gio, regi_gio, rw_pa_oe), $r1 + move.d $r0, [$r1] + + ;; 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 + ;; in the flash (since we wont try to copy it to DRAM + ;; before unpacking). It is at _edata, but in flash. + ;; Use (_edata - herami) as offset to the current PC. + + move.d REG_ADDR(config, regi_config, r_bootsel), $r0 + move.d [$r0], $r0 + and.d REG_MASK(config, r_bootsel, boot_mode), $r0 + cmp.d REG_STATE(config, r_bootsel, boot_mode, nand), $r0 + beq hereami2 + nop +hereami: + lapcq ., $r5 ; get PC + and.d 0x7fffffff, $r5 ; strip any non-cache bit + move.d $r5, $r0 ; save for later - flash address of 'herami' + add.d _edata, $r5 + sub.d hereami, $r5 ; r5 = flash address of '_edata' + move.d hereami, $r1 ; destination + ba 2f + nop +hereami2: + lapcq ., $r5 ; get PC + and.d 0x00ffffff, $r5 ; strip any non-cache bit + move.d $r5, $r6 + or.d 0x40200000, $r6 + move.d $r6, $r0 ; save for later - flash address of 'herami' + add.d _edata, $r5 + sub.d hereami2, $r5 ; r5 = flash address of '_edata' + add.d 0x40200000, $r5 + move.d hereami2, $r1 ; destination +2: + ;; Copy text+data to DRAM + + move.d _edata, $r2 ; end destination +1: move.w [$r0+], $r3 + move.w $r3, [$r1+] + cmp.d $r2, $r1 + 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, $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 + nop + + ;; 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 0x40200000, $r9 + blo enter_kernel + nop + sub.d 0x40200000, $r9 + add.d 0x4000, $r9 + +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 +is_nand_boot: + .dword 0 + +#include "../../lib/hw_settings.S" |