/* * Kernel relocation stub for MIPS devices * * Copyright (C) 2015 Felix Fietkau * * Based on: * * LZMA compressed kernel loader for Atheros AR7XXX/AR9XXX based boards * * Copyright (C) 2011 Gabor Juhos * * 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 * * 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 #include #include "cp0regdef.h" #include "cacheops.h" #define KSEG0 0x80000000 .macro ehb sll zero, 3 .endm .macro reset li t0, 0xbe000034 lw t1, 0(t0) ori t1, 1 sw t1, 0(t0) .endm .text LEAF(startup) .set noreorder .set mips32 .fill 0x10000 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 /* 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 t4, t2, t0 # calculate actual address of _code_end lw t5, 0(t4) # get extra data size add t2, t5 add t2, 4 add 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 la t0, __reloc_back j t0 nop __reloc_back: la t0, _code_end add t0, 4 addu t1, t0, t5 li t2, KERNEL_ADDR __kernel_copy: lw t3, 0(t0) sw t3, 0(t2) add t0, 4 blt t0, t1, __kernel_copy add t2, 4 /* flush cache */ li t0, KERNEL_ADDR addu t1, t0, t5 add t1, CONFIG_CACHELINE_SIZE - 1 li t2, ~(CONFIG_CACHELINE_SIZE - 1) and t0, t2 and t1, t2 li t2, CONFIG_CACHELINE_SIZE b __kernel_flush_check nop __kernel_flush_line: cache Hit_Writeback_Inv_D, 0(t0) cache Hit_Invalidate_I, 0(t0) add t0, t2 __kernel_flush_check: bne t0, t1, __kernel_flush_line nop sync li t0, KERNEL_ADDR jr t0 nop .set reorder END(startup)