diff options
Diffstat (limited to 'arch/openrisc/cpu/start.S')
| -rw-r--r-- | arch/openrisc/cpu/start.S | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/arch/openrisc/cpu/start.S b/arch/openrisc/cpu/start.S new file mode 100644 index 0000000..3a42717 --- /dev/null +++ b/arch/openrisc/cpu/start.S @@ -0,0 +1,335 @@ +/* + * (C) Copyright 2011, Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> + * (C) Copyright 2011, Julius Baxter <julius@opencores.org> + * + * 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 <asm-offsets.h> +#include <asm/spr-defs.h> + +#define EXCEPTION_STACK_SIZE (128+128) + +#define HANDLE_EXCEPTION \ + l.addi r1, r1, -EXCEPTION_STACK_SIZE ;\ + l.sw 0x1c(r1), r9 ;\ + l.jal _exception_handler ;\ + l.nop ;\ + l.lwz r9, 0x1c(r1) ;\ + l.addi r1, r1, EXCEPTION_STACK_SIZE ;\ + l.rfe ;\ + l.nop + + .section .vectors, "ax" + .global __reset + + /* reset */ + .org 0x100 +__reset: + /* there is no guarantee r0 is hardwired to zero, clear it here */ + l.andi r0, r0, 0 + /* reset stack and frame pointers */ + l.andi r1, r0, 0 + l.andi r2, r0, 0 + + /* set supervisor mode */ + l.ori r3,r0,SPR_SR_SM + l.mtspr r0,r3,SPR_SR + + /* Relocate u-boot */ + l.movhi r3,hi(__start) /* source start address */ + l.ori r3,r3,lo(__start) + l.movhi r4,hi(_stext) /* dest start address */ + l.ori r4,r4,lo(_stext) + l.movhi r5,hi(__end) /* dest end address */ + l.ori r5,r5,lo(__end) + +.L_reloc: + l.lwz r6,0(r3) + l.sw 0(r4),r6 + l.addi r3,r3,4 + l.sfltu r4,r5 + l.bf .L_reloc + l.addi r4,r4,4 /* delay slot */ + +#ifdef CONFIG_SYS_RELOCATE_VECTORS + /* Relocate vectors from 0xf0000000 to 0x00000000 */ + l.movhi r4, 0xf000 /* source */ + l.movhi r5, 0 /* destination */ + l.addi r6, r5, CONFIG_SYS_VECTORS_LEN /* length */ +.L_relocvectors: + l.lwz r7, 0(r4) + l.sw 0(r5), r7 + l.addi r5, r5, 4 + l.sfeq r5,r6 + l.bnf .L_relocvectors + l.addi r4,r4, 4 +#endif + + l.j _start + l.nop + + /* bus error */ + .org 0x200 + HANDLE_EXCEPTION + + /* data page fault */ + .org 0x300 + HANDLE_EXCEPTION + + /* instruction page fault */ + .org 0x400 + HANDLE_EXCEPTION + + /* tick timer */ + .org 0x500 + HANDLE_EXCEPTION + + /* alignment */ + .org 0x600 + HANDLE_EXCEPTION + + /* illegal instruction */ + .org 0x700 + HANDLE_EXCEPTION + + /* external interrupt */ + .org 0x800 + HANDLE_EXCEPTION + + /* D-TLB miss */ + .org 0x900 + HANDLE_EXCEPTION + + /* I-TLB miss */ + .org 0xa00 + HANDLE_EXCEPTION + + /* range */ + .org 0xb00 + HANDLE_EXCEPTION + + /* system call */ + .org 0xc00 + HANDLE_EXCEPTION + + /* floating point */ + .org 0xd00 + HANDLE_EXCEPTION + + /* trap */ + .org 0xe00 + HANDLE_EXCEPTION + + /* reserved */ + .org 0xf00 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1100 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1200 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1300 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1400 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1500 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1600 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1700 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1800 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1900 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1a00 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1b00 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1c00 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1d00 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1e00 + HANDLE_EXCEPTION + + /* reserved */ + .org 0x1f00 + HANDLE_EXCEPTION + + /* Startup routine */ + .text + .global _start +_start: + /* Init stack and frame pointers */ + l.movhi r1, hi(CONFIG_SYS_INIT_SP_ADDR) + l.ori r1, r1, lo(CONFIG_SYS_INIT_SP_ADDR) + l.or r2, r0, r1 + + /* clear BSS segments */ + l.movhi r4, hi(_bss_start) + l.ori r4, r4, lo(_bss_start) + l.movhi r5, hi(_bss_end) + l.ori r5, r5, lo(_bss_end) +.L_clear_bss: + l.sw 0(r4), r0 + l.sfltu r4,r5 + l.bf .L_clear_bss + l.addi r4,r4,4 + + /* Reset registers before jumping to board_init */ + l.andi r3, r0, 0 + l.andi r4, r0, 0 + l.andi r5, r0, 0 + l.andi r6, r0, 0 + l.andi r7, r0, 0 + l.andi r8, r0, 0 + l.andi r9, r0, 0 + l.andi r10, r0, 0 + l.andi r11, r0, 0 + l.andi r12, r0, 0 + l.andi r13, r0, 0 + l.andi r14, r0, 0 + l.andi r15, r0, 0 + l.andi r17, r0, 0 + l.andi r18, r0, 0 + l.andi r19, r0, 0 + l.andi r20, r0, 0 + l.andi r21, r0, 0 + l.andi r22, r0, 0 + l.andi r23, r0, 0 + l.andi r24, r0, 0 + l.andi r25, r0, 0 + l.andi r26, r0, 0 + l.andi r27, r0, 0 + l.andi r28, r0, 0 + l.andi r29, r0, 0 + l.andi r30, r0, 0 + l.andi r31, r0, 0 + + l.j board_init + l.nop + + .size _start, .-_start + +/* + * Store state onto stack and call the real exception handler + */ + .section .text + .extern exception_handler + .type _exception_handler,@function + +_exception_handler: + /* Store state (r9 already saved)*/ + l.sw 0x00(r1), r2 + l.sw 0x04(r1), r3 + l.sw 0x08(r1), r4 + l.sw 0x0c(r1), r5 + l.sw 0x10(r1), r6 + l.sw 0x14(r1), r7 + l.sw 0x18(r1), r8 + l.sw 0x20(r1), r10 + l.sw 0x24(r1), r11 + l.sw 0x28(r1), r12 + l.sw 0x2c(r1), r13 + l.sw 0x30(r1), r14 + l.sw 0x34(r1), r15 + l.sw 0x38(r1), r16 + l.sw 0x3c(r1), r17 + l.sw 0x40(r1), r18 + l.sw 0x44(r1), r19 + l.sw 0x48(r1), r20 + l.sw 0x4c(r1), r21 + l.sw 0x50(r1), r22 + l.sw 0x54(r1), r23 + l.sw 0x58(r1), r24 + l.sw 0x5c(r1), r25 + l.sw 0x60(r1), r26 + l.sw 0x64(r1), r27 + l.sw 0x68(r1), r28 + l.sw 0x6c(r1), r29 + l.sw 0x70(r1), r30 + l.sw 0x74(r1), r31 + + /* Save return address */ + l.or r14, r0, r9 + /* Call exception handler with the link address as argument */ + l.jal exception_handler + l.or r3, r0, r14 + /* Load return address */ + l.or r9, r0, r14 + + /* Restore state */ + l.lwz r2, 0x00(r1) + l.lwz r3, 0x04(r1) + l.lwz r4, 0x08(r1) + l.lwz r5, 0x0c(r1) + l.lwz r6, 0x10(r1) + l.lwz r7, 0x14(r1) + l.lwz r8, 0x18(r1) + l.lwz r10, 0x20(r1) + l.lwz r11, 0x24(r1) + l.lwz r12, 0x28(r1) + l.lwz r13, 0x2c(r1) + l.lwz r14, 0x30(r1) + l.lwz r15, 0x34(r1) + l.lwz r16, 0x38(r1) + l.lwz r17, 0x3c(r1) + l.lwz r18, 0x40(r1) + l.lwz r19, 0x44(r1) + l.lwz r20, 0x48(r1) + l.lwz r21, 0x4c(r1) + l.lwz r22, 0x50(r1) + l.lwz r23, 0x54(r1) + l.lwz r24, 0x58(r1) + l.lwz r25, 0x5c(r1) + l.lwz r26, 0x60(r1) + l.lwz r27, 0x64(r1) + l.lwz r28, 0x68(r1) + l.lwz r29, 0x6c(r1) + l.lwz r30, 0x70(r1) + l.lwz r31, 0x74(r1) + l.jr r9 + l.nop |