diff options
Diffstat (limited to 'target/linux/ath79/image/lzma-loader/src/head.S')
| -rw-r--r-- | target/linux/ath79/image/lzma-loader/src/head.S | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/target/linux/ath79/image/lzma-loader/src/head.S b/target/linux/ath79/image/lzma-loader/src/head.S new file mode 100644 index 0000000..47a7c9b --- /dev/null +++ b/target/linux/ath79/image/lzma-loader/src/head.S @@ -0,0 +1,121 @@ +/* + * LZMA compressed kernel loader for Atheros AR7XXX/AR9XXX based boards + * + * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> + * + * Some parts of this code was based on the OpenWrt specific lzma-loader + * for the BCM47xx and ADM5120 based boards: + * Copyright (C) 2004 Manuel Novoa III (mjn3@codepoet.org) + * Copyright (C) 2005 by Oleg I. Vdovikin <oleg@cs.msu.su> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <asm/asm.h> +#include <asm/regdef.h> +#include "cp0regdef.h" +#include "cacheops.h" +#include "config.h" + +#define KSEG0 0x80000000 + + .macro ehb + sll zero, 3 + .endm + + .text + +LEAF(startup) + .set noreorder + .set mips32 + + mtc0 zero, CP0_WATCHLO # clear watch registers + mtc0 zero, CP0_WATCHHI + mtc0 zero, CP0_CAUSE # clear before writing status register + + mfc0 t0, CP0_STATUS + li t1, 0x1000001f + or t0, t1 + xori t0, 0x1f + mtc0 t0, CP0_STATUS + ehb + + mtc0 zero, CP0_COUNT + mtc0 zero, CP0_COMPARE + ehb + + la t0, __reloc_label # get linked address of label + bal __reloc_label # branch and link to label to + nop # get actual address +__reloc_label: + subu t0, ra, t0 # get reloc_delta + + beqz t0, __reloc_done # if delta is 0 we are in the right place + nop + + /* Copy our code to the right place */ + la t1, _code_start # get linked address of _code_start + la t2, _code_end # get linked address of _code_end + addu t0, t0, t1 # calculate actual address of _code_start + +__reloc_copy: + lw t3, 0(t0) + sw t3, 0(t1) + add t1, 4 + blt t1, t2, __reloc_copy + add t0, 4 + + /* flush cache */ + la t0, _code_start + la t1, _code_end + + li t2, ~(CONFIG_CACHELINE_SIZE - 1) + and t0, t2 + and t1, t2 + li t2, CONFIG_CACHELINE_SIZE + + b __flush_check + nop + +__flush_line: + cache Hit_Writeback_Inv_D, 0(t0) + cache Hit_Invalidate_I, 0(t0) + add t0, t2 + +__flush_check: + bne t0, t1, __flush_line + nop + + sync + +__reloc_done: + + /* clear bss */ + la t0, _bss_start + la t1, _bss_end + b __bss_check + nop + +__bss_fill: + sw zero, 0(t0) + addi t0, 4 + +__bss_check: + bne t0, t1, __bss_fill + nop + + /* Setup new "C" stack */ + la sp, _stack + + /* reserve stack space for a0-a3 registers */ + subu sp, 16 + + /* jump to the decompressor routine */ + la t0, loader_main + jr t0 + nop + + .set reorder +END(startup) |