| /* |
| * Code that sets up the DRAM registers, calls the |
| * decompressor to unpack the piggybacked kernel, and jumps. |
| * |
| * Copyright (C) 1999 - 2003, Axis Communications AB |
| */ |
| |
| #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" |
