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Diffstat (limited to 'cpu/mips/start.S')
| -rw-r--r-- | cpu/mips/start.S | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/cpu/mips/start.S b/cpu/mips/start.S new file mode 100644 index 000000000..bf1165561 --- /dev/null +++ b/cpu/mips/start.S @@ -0,0 +1,350 @@ +/* + * Startup Code for MIPS32 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 later 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 PARTICULAR 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 Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + + +#include <config.h> +#include <version.h> +#include <asm/regdef.h> +#include <asm/mipsregs.h> + + +#define RVECENT(f,n) \ + b f; nop +#define XVECENT(f,bev) \ + b f ; \ + li k0,bev + + .set noreorder + + .globl _start + .text +_start: + RVECENT(reset,0) /* U-boot entry point */ + RVECENT(reset,1) /* software reboot */ +#ifdef CONFIG_INCA_IP + .word 0x000020C4 /* EBU init code, fetched during booting */ + .word 0x00000000 /* phase of the flash */ +#else + RVECENT(romReserved,2) +#endif + RVECENT(romReserved,3) + RVECENT(romReserved,4) + RVECENT(romReserved,5) + RVECENT(romReserved,6) + RVECENT(romReserved,7) + RVECENT(romReserved,8) + RVECENT(romReserved,9) + RVECENT(romReserved,10) + RVECENT(romReserved,11) + RVECENT(romReserved,12) + RVECENT(romReserved,13) + RVECENT(romReserved,14) + RVECENT(romReserved,15) + RVECENT(romReserved,16) + RVECENT(romReserved,17) + RVECENT(romReserved,18) + RVECENT(romReserved,19) + RVECENT(romReserved,20) + RVECENT(romReserved,21) + RVECENT(romReserved,22) + RVECENT(romReserved,23) + RVECENT(romReserved,24) + RVECENT(romReserved,25) + RVECENT(romReserved,26) + RVECENT(romReserved,27) + RVECENT(romReserved,28) + RVECENT(romReserved,29) + RVECENT(romReserved,30) + RVECENT(romReserved,31) + RVECENT(romReserved,32) + RVECENT(romReserved,33) + RVECENT(romReserved,34) + RVECENT(romReserved,35) + RVECENT(romReserved,36) + RVECENT(romReserved,37) + RVECENT(romReserved,38) + RVECENT(romReserved,39) + RVECENT(romReserved,40) + RVECENT(romReserved,41) + RVECENT(romReserved,42) + RVECENT(romReserved,43) + RVECENT(romReserved,44) + RVECENT(romReserved,45) + RVECENT(romReserved,46) + RVECENT(romReserved,47) + RVECENT(romReserved,48) + RVECENT(romReserved,49) + RVECENT(romReserved,50) + RVECENT(romReserved,51) + RVECENT(romReserved,52) + RVECENT(romReserved,53) + RVECENT(romReserved,54) + RVECENT(romReserved,55) + RVECENT(romReserved,56) + RVECENT(romReserved,57) + RVECENT(romReserved,58) + RVECENT(romReserved,59) + RVECENT(romReserved,60) + RVECENT(romReserved,61) + RVECENT(romReserved,62) + RVECENT(romReserved,63) + XVECENT(romExcHandle,0x200) /* bfc00200: R4000 tlbmiss vector */ + RVECENT(romReserved,65) + RVECENT(romReserved,66) + RVECENT(romReserved,67) + RVECENT(romReserved,68) + RVECENT(romReserved,69) + RVECENT(romReserved,70) + RVECENT(romReserved,71) + RVECENT(romReserved,72) + RVECENT(romReserved,73) + RVECENT(romReserved,74) + RVECENT(romReserved,75) + RVECENT(romReserved,76) + RVECENT(romReserved,77) + RVECENT(romReserved,78) + RVECENT(romReserved,79) + XVECENT(romExcHandle,0x280) /* bfc00280: R4000 xtlbmiss vector */ + RVECENT(romReserved,81) + RVECENT(romReserved,82) + RVECENT(romReserved,83) + RVECENT(romReserved,84) + RVECENT(romReserved,85) + RVECENT(romReserved,86) + RVECENT(romReserved,87) + RVECENT(romReserved,88) + RVECENT(romReserved,89) + RVECENT(romReserved,90) + RVECENT(romReserved,91) + RVECENT(romReserved,92) + RVECENT(romReserved,93) + RVECENT(romReserved,94) + RVECENT(romReserved,95) + XVECENT(romExcHandle,0x300) /* bfc00300: R4000 cache vector */ + RVECENT(romReserved,97) + RVECENT(romReserved,98) + RVECENT(romReserved,99) + RVECENT(romReserved,100) + RVECENT(romReserved,101) + RVECENT(romReserved,102) + RVECENT(romReserved,103) + RVECENT(romReserved,104) + RVECENT(romReserved,105) + RVECENT(romReserved,106) + RVECENT(romReserved,107) + RVECENT(romReserved,108) + RVECENT(romReserved,109) + RVECENT(romReserved,110) + RVECENT(romReserved,111) + XVECENT(romExcHandle,0x380) /* bfc00380: R4000 general vector */ + RVECENT(romReserved,113) + RVECENT(romReserved,114) + RVECENT(romReserved,115) + RVECENT(romReserved,116) + RVECENT(romReserved,116) + RVECENT(romReserved,118) + RVECENT(romReserved,119) + RVECENT(romReserved,120) + RVECENT(romReserved,121) + RVECENT(romReserved,122) + RVECENT(romReserved,123) + RVECENT(romReserved,124) + RVECENT(romReserved,125) + RVECENT(romReserved,126) + RVECENT(romReserved,127) + + /* We hope there are no more reserved vectors! + * 128 * 8 == 1024 == 0x400 + * so this is address R_VEC+0x400 == 0xbfc00400 + */ + .align 4 +reset: + + /* Clear watch registers. + */ + mtc0 zero, CP0_WATCHLO + mtc0 zero, CP0_WATCHHI + + /* STATUS register */ + mfc0 k0, CP0_STATUS + li k1, ~ST0_IE + and k0, k1 + mtc0 k0, CP0_STATUS + + /* CAUSE register */ + mtc0 zero, CP0_CAUSE + + /* Init Timer */ + mtc0 zero, CP0_COUNT + mtc0 zero, CP0_COMPARE + + /* CONFIG0 register */ + li t0, CONF_CM_UNCACHED + mtc0 t0, CP0_CONFIG + +#ifdef CONFIG_INCA_IP + /* Disable INCA-IP Watchdog. + */ + bal disable_incaip_wdt + nop +#endif + + /* Initialize any external memory. + */ + bal memsetup + nop + + /* Initialize caches... + */ + bal mips_cache_reset + nop + + /* ... and enable them. + */ + li t0, CONF_CM_CACHABLE_NONCOHERENT + mtc0 t0, CP0_CONFIG + + + /* Set up temporary stack. + */ + li a0, CFG_INIT_SP_OFFSET + bal mips_cache_lock + nop + + li t0, CFG_SDRAM_BASE + CFG_INIT_SP_OFFSET + la sp, 0(t0) + + /* Initialize GOT pointer. + */ + bal 1f + nop + .word _GLOBAL_OFFSET_TABLE_ - 1f + 4 +1: + move gp, ra + lw t1, 0(ra) + add gp, t1 + la t9, board_init_f + j 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 */ + + /* + * Fix GOT pointer: + * + * New GOT-PTR = (old GOT-PTR - CFG_MONITOR_BASE) + Destination Address + */ + move t6, gp + sub gp, CFG_MONITOR_BASE + add gp, a2 /* gp now adjusted */ + sub t6, gp, t6 /* t6 <-- relocation offset */ + + li t0, CFG_MONITOR_BASE + add t2, t0, CFG_MONITOR_LEN + move t1, a2 + + /* + * t0 = source address + * t1 = target address + * t2 = source end address + */ +1: + lw t3, 0(t0) + sw t3, 0(t1) + addu t0, 4 + ble t0, t2, 1b + addu t1, 4 /* delay slot */ + + /* If caches were enabled, we would have to flush them here. + */ + + /* Jump to where we've relocated ourselves. + */ + addi t0, a2, in_ram - _start + j t0 + nop + + .word uboot_end_data + .word uboot_end + .word num_got_entries + +in_ram: + /* Now we want to update GOT. + */ + lw t3, -4(t0) /* t3 <-- num_got_entries */ + addi t4, gp, 8 /* Skipping first two entries. */ + li t2, 2 +1: + lw t1, 0(t4) + beqz t1, 2f + add t1, t6 + sw t1, 0(t4) +2: + addi t2, 1 + blt t2, t3, 1b + addi t4, 4 /* delay slot */ + + /* Clear BSS. + */ + lw t1, -12(t0) /* t1 <-- uboot_end_data */ + lw t2, -8(t0) /* t2 <-- uboot_end */ + add t1, t6 /* adjust pointers */ + add t2, t6 + + sub t1, 4 +1: addi t1, 4 + bltl t1, t2, 1b + sw zero, 0(t1) /* delay slot */ + + move a0, a1 + la t9, board_init_r + j t9 + move a1, a2 /* delay slot */ + + .end relocate_code + + + + /* Exception handlers. + */ +romReserved: + b romReserved + +romExcHandle: + b romExcHandle + |