diff options
Diffstat (limited to 'arch/mips/cpu/mips64/start.S')
| -rw-r--r-- | arch/mips/cpu/mips64/start.S | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/arch/mips/cpu/mips64/start.S b/arch/mips/cpu/mips64/start.S new file mode 100644 index 0000000..4112de7 --- /dev/null +++ b/arch/mips/cpu/mips64/start.S @@ -0,0 +1,256 @@ +/* + * Startup Code for MIPS64 CPU-core + * + * Copyright (c) 2003 Wolfgang Denk <wd@denx.de> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any dlater version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICUdlaR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Pdlace, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <asm-offsets.h> +#include <config.h> +#include <asm/regdef.h> +#include <asm/mipsregs.h> + +#ifndef CONFIG_SYS_MIPS_CACHE_MODE +#define CONFIG_SYS_MIPS_CACHE_MODE CONF_CM_CACHABLE_NONCOHERENT +#endif + + /* + * For the moment disable interrupts, mark the kernel mode and + * set ST0_KX so that the CPU does not spit fire when using + * 64-bit addresses. + */ + .macro setup_c0_status set clr + .set push + mfc0 t0, CP0_STATUS + or t0, ST0_CU0 | \set | 0x1f | \clr + xor t0, 0x1f | \clr + mtc0 t0, CP0_STATUS + .set noreorder + sll zero, 3 # ehb + .set pop + .endm + + .set noreorder + + .globl _start + .text +_start: + .org 0x000 + b reset + nop + .org 0x080 + b romReserved + nop + .org 0x100 + b romReserved + nop + .org 0x180 + b romReserved + nop + .org 0x200 + b romReserved + nop + .org 0x280 + b romReserved + nop + .org 0x300 + b romReserved + nop + .org 0x380 + b romReserved + nop + .org 0x480 + b romReserved + nop + + /* + * We hope there are no more reserved vectors! + * 128 * 8 == 1024 == 0x400 + * so this is address R_VEC+0x400 == 0xbfc00400 + */ + .org 0x500 + .align 4 +reset: + + /* Clear watch registers */ + dmtc0 zero, CP0_WATCHLO + dmtc0 zero, CP0_WATCHHI + + /* WP(Watch Pending), SW0/1 should be cleared */ + mtc0 zero, CP0_CAUSE + + setup_c0_status ST0_KX 0 + + /* Init Timer */ + mtc0 zero, CP0_COUNT + mtc0 zero, CP0_COMPARE + +#ifndef CONFIG_SKIP_LOWLEVEL_INIT + /* CONFIG0 register */ + dli t0, CONF_CM_UNCACHED + mtc0 t0, CP0_CONFIG +#endif + + /* Initialize $gp */ + bal 1f + nop + .dword _gp +1: + ld gp, 0(ra) + +#ifndef CONFIG_SKIP_LOWLEVEL_INIT + /* Initialize any external memory */ + dla t9, lowlevel_init + jalr t9 + nop + + /* Initialize caches... */ + dla t9, mips_cache_reset + jalr t9 + nop + + /* ... and enable them */ + dli t0, CONFIG_SYS_MIPS_CACHE_MODE + mtc0 t0, CP0_CONFIG +#endif + + /* Set up temporary stack */ + dli t0, CONFIG_SYS_SDRAM_BASE + CONFIG_SYS_INIT_SP_OFFSET + dla sp, 0(t0) + + dla t9, board_init_f + jr t9 + nop + +/* + * void relocate_code (addr_sp, gd, addr_moni) + * + * This "function" does not return, instead it continues in RAM + * after relocating the monitor code. + * + * a0 = addr_sp + * a1 = gd + * a2 = destination address + */ + .globl relocate_code + .ent relocate_code +relocate_code: + move sp, a0 # set new stack pointer + + dli t0, CONFIG_SYS_MONITOR_BASE + dla t3, in_ram + ld t2, -24(t3) # t2 <-- uboot_end_data + move t1, a2 + move s2, a2 # s2 <-- destination address + + /* + * Fix $gp: + * + * New $gp = (Old $gp - CONFIG_SYS_MONITOR_BASE) + Destination Address + */ + move t8, gp + dsub gp, CONFIG_SYS_MONITOR_BASE + dadd gp, a2 # gp now adjusted + dsub s1, gp, t8 # s1 <-- relocation offset + + /* + * t0 = source address + * t1 = target address + * t2 = source end address + */ + + /* + * Save destination address and size for dlater usage in flush_cache() + */ + move s0, a1 # save gd in s0 + move a0, t1 # a0 <-- destination addr + dsub a1, t2, t0 # a1 <-- size + +1: + lw t3, 0(t0) + sw t3, 0(t1) + daddu t0, 4 + ble t0, t2, 1b + daddu t1, 4 + + /* If caches were enabled, we would have to flush them here. */ + + /* a0 & a1 are already set up for flush_cache(start, size) */ + dla t9, flush_cache + jalr t9 + nop + + /* Jump to where we've relocated ourselves */ + daddi t0, s2, in_ram - _start + jr t0 + nop + + .dword _gp + .dword _GLOBAL_OFFSET_TABLE_ + .dword uboot_end_data + .dword uboot_end + .dword num_got_entries + +in_ram: + /* + * Now we want to update GOT. + * + * GOT[0] is reserved. GOT[1] is also reserved for the dynamic object + * generated by GNU ld. Skip these reserved entries from relocation. + */ + ld t3, -8(t0) # t3 <-- num_got_entries + ld t8, -32(t0) # t8 <-- _GLOBAL_OFFSET_TABLE_ + ld t9, -40(t0) # t9 <-- _gp + dsub t8, t9 # compute offset + dadd t8, t8, gp # t8 now holds relocated _G_O_T_ + daddi t8, t8, 16 # skipping first two entries + dli t2, 2 +1: + ld t1, 0(t8) + beqz t1, 2f + dadd t1, s1 + sd t1, 0(t8) +2: + daddi t2, 1 + blt t2, t3, 1b + daddi t8, 8 + + /* Clear BSS */ + ld t1, -24(t0) # t1 <-- uboot_end_data + ld t2, -16(t0) # t2 <-- uboot_end + dadd t1, s1 # adjust pointers + dadd t2, s1 + + dsub t1, 8 +1: + daddi t1, 8 + bltl t1, t2, 1b + sd zero, 0(t1) + + move a0, s0 # a0 <-- gd + dla t9, board_init_r + jr t9 + move a1, s2 + + .end relocate_code + + /* Exception handlers */ +romReserved: + b romReserved |