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Diffstat (limited to 'cpu/arm1176/start.S')
| -rw-r--r-- | cpu/arm1176/start.S | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/cpu/arm1176/start.S b/cpu/arm1176/start.S new file mode 100644 index 0000000..991277f --- /dev/null +++ b/cpu/arm1176/start.S @@ -0,0 +1,469 @@ +/* + * armboot - Startup Code for S3C6400/ARM1176 CPU-core + * + * Copyright (c) 2007 Samsung Electronics + * + * Copyright (C) 2008 + * Guennadi Liakhovetki, DENX Software Engineering, <lg@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 + * + * 2007-09-21 - Restructured codes by jsgood (jsgood.yang@samsung.com) + * 2007-09-21 - Added MoviNAND and OneNAND boot codes by + * jsgood (jsgood.yang@samsung.com) + * Base codes by scsuh (sc.suh) + */ + +#include <config.h> +#include <version.h> +#ifdef CONFIG_ENABLE_MMU +#include <asm/proc/domain.h> +#endif +#include <s3c6400.h> + +#if !defined(CONFIG_ENABLE_MMU) && !defined(CFG_PHY_UBOOT_BASE) +#define CFG_PHY_UBOOT_BASE CFG_UBOOT_BASE +#endif + +/* + ************************************************************************* + * + * Jump vector table as in table 3.1 in [1] + * + ************************************************************************* + */ + +.globl _start +_start: b reset +#ifndef CONFIG_NAND_SPL + ldr pc, _undefined_instruction + ldr pc, _software_interrupt + ldr pc, _prefetch_abort + ldr pc, _data_abort + ldr pc, _not_used + ldr pc, _irq + ldr pc, _fiq + +_undefined_instruction: + .word undefined_instruction +_software_interrupt: + .word software_interrupt +_prefetch_abort: + .word prefetch_abort +_data_abort: + .word data_abort +_not_used: + .word not_used +_irq: + .word irq +_fiq: + .word fiq +_pad: + .word 0x12345678 /* now 16*4=64 */ +#else + . = _start + 64 +#endif + +.global _end_vect +_end_vect: + .balignl 16,0xdeadbeef +/* + ************************************************************************* + * + * Startup Code (reset vector) + * + * do important init only if we don't start from memory! + * setup Memory and board specific bits prior to relocation. + * relocate armboot to ram + * setup stack + * + ************************************************************************* + */ + +_TEXT_BASE: + .word TEXT_BASE + +/* + * Below variable is very important because we use MMU in U-Boot. + * Without it, we cannot run code correctly before MMU is ON. + * by scsuh. + */ +_TEXT_PHY_BASE: + .word CFG_PHY_UBOOT_BASE + +.globl _armboot_start +_armboot_start: + .word _start + +/* + * These are defined in the board-specific linker script. + */ +.globl _bss_start +_bss_start: + .word __bss_start + +.globl _bss_end +_bss_end: + .word _end + +/* + * the actual reset code + */ + +reset: + /* + * set the cpu to SVC32 mode + */ + mrs r0, cpsr + bic r0, r0, #0x3f + orr r0, r0, #0xd3 + msr cpsr, r0 + +/* + ************************************************************************* + * + * CPU_init_critical registers + * + * setup important registers + * setup memory timing + * + ************************************************************************* + */ + /* + * we do sys-critical inits only at reboot, + * not when booting from ram! + */ +cpu_init_crit: + /* + * When booting from NAND - it has definitely been a reset, so, no need + * to flush caches and disable the MMU + */ +#ifndef CONFIG_NAND_SPL + /* + * flush v4 I/D caches + */ + mov r0, #0 + mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */ + mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */ + + /* + * disable MMU stuff and caches + */ + mrc p15, 0, r0, c1, c0, 0 + bic r0, r0, #0x00002300 @ clear bits 13, 9:8 (--V- --RS) + bic r0, r0, #0x00000087 @ clear bits 7, 2:0 (B--- -CAM) + orr r0, r0, #0x00000002 @ set bit 2 (A) Align + orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache + /* Prepare to disable the MMU */ + adr r1, mmu_disable_phys + /* We presume we're within the first 1024 bytes */ + and r1, r1, #0x3fc + ldr r2, _TEXT_PHY_BASE + ldr r3, =0xfff00000 + and r2, r2, r3 + orr r2, r2, r1 + b mmu_disable + + .align 5 + /* Run in a single cache-line */ +mmu_disable: + mcr p15, 0, r0, c1, c0, 0 + nop + nop + mov pc, r2 +#endif + +mmu_disable_phys: + /* Peri port setup */ + ldr r0, =0x70000000 + orr r0, r0, #0x13 + mcr p15,0,r0,c15,c2,4 @ 256M (0x70000000 - 0x7fffffff) + + /* + * Go setup Memory and board specific bits prior to relocation. + */ + bl lowlevel_init /* go setup pll,mux,memory */ + +after_copy: +#ifdef CONFIG_ENABLE_MMU +enable_mmu: + /* enable domain access */ + ldr r5, =0x0000ffff + mcr p15, 0, r5, c3, c0, 0 /* load domain access register */ + + /* Set the TTB register */ + ldr r0, _mmu_table_base + ldr r1, =CFG_PHY_UBOOT_BASE + ldr r2, =0xfff00000 + bic r0, r0, r2 + orr r1, r0, r1 + mcr p15, 0, r1, c2, c0, 0 + + /* Enable the MMU */ + mrc p15, 0, r0, c1, c0, 0 + orr r0, r0, #1 /* Set CR_M to enable MMU */ + + /* Prepare to enable the MMU */ + adr r1, skip_hw_init + and r1, r1, #0x3fc + ldr r2, _TEXT_BASE + ldr r3, =0xfff00000 + and r2, r2, r3 + orr r2, r2, r1 + b mmu_enable + + .align 5 + /* Run in a single cache-line */ +mmu_enable: + + mcr p15, 0, r0, c1, c0, 0 + nop + nop + mov pc, r2 +#endif + +skip_hw_init: + /* Set up the stack */ +stack_setup: +#ifdef CONFIG_MEMORY_UPPER_CODE + ldr sp, =(CFG_UBOOT_BASE + CFG_UBOOT_SIZE - 0xc) +#else + ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */ + sub r0, r0, #CFG_MALLOC_LEN /* malloc area */ + sub r0, r0, #CFG_GBL_DATA_SIZE /* bdinfo */ + sub sp, r0, #12 /* leave 3 words for abort-stack */ + +#endif + +clear_bss: + ldr r0, _bss_start /* find start of bss segment */ + ldr r1, _bss_end /* stop here */ + mov r2, #0 /* clear */ + +clbss_l: + str r2, [r0] /* clear loop... */ + add r0, r0, #4 + cmp r0, r1 + ble clbss_l + +#ifndef CONFIG_NAND_SPL + ldr pc, _start_armboot + +_start_armboot: + .word start_armboot +#else + b nand_boot +/* .word nand_boot*/ +#endif + +#ifdef CONFIG_ENABLE_MMU +_mmu_table_base: + .word mmu_table +#endif + +#ifndef CONFIG_NAND_SPL +/* + * we assume that cache operation is done before. (eg. cleanup_before_linux()) + * actually, we don't need to do anything about cache if not use d-cache in + * U-Boot. So, in this function we clean only MMU. by scsuh + * + * void theLastJump(void *kernel, int arch_num, uint boot_params); + */ +#ifdef CONFIG_ENABLE_MMU + .globl theLastJump +theLastJump: + mov r9, r0 + ldr r3, =0xfff00000 + ldr r4, _TEXT_PHY_BASE + adr r5, phy_last_jump + bic r5, r5, r3 + orr r5, r5, r4 + mov pc, r5 +phy_last_jump: + /* + * disable MMU stuff + */ + mrc p15, 0, r0, c1, c0, 0 + bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */ + bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */ + orr r0, r0, #0x00000002 /* set bit 2 (A) Align */ + orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */ + mcr p15, 0, r0, c1, c0, 0 + + mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */ + + mov r0, #0 + mov pc, r9 +#endif +/* + ************************************************************************* + * + * Interrupt handling + * + ************************************************************************* + */ +@ +@ IRQ stack frame. +@ +#define S_FRAME_SIZE 72 + +#define S_OLD_R0 68 +#define S_PSR 64 +#define S_PC 60 +#define S_LR 56 +#define S_SP 52 + +#define S_IP 48 +#define S_FP 44 +#define S_R10 40 +#define S_R9 36 +#define S_R8 32 +#define S_R7 28 +#define S_R6 24 +#define S_R5 20 +#define S_R4 16 +#define S_R3 12 +#define S_R2 8 +#define S_R1 4 +#define S_R0 0 + +#define MODE_SVC 0x13 +#define I_BIT 0x80 + +/* + * use bad_save_user_regs for abort/prefetch/undef/swi ... + */ + + .macro bad_save_user_regs + /* carve out a frame on current user stack */ + sub sp, sp, #S_FRAME_SIZE + /* Save user registers (now in svc mode) r0-r12 */ + stmia sp, {r0 - r12} + + ldr r2, _armboot_start + sub r2, r2, #(CFG_MALLOC_LEN) + /* set base 2 words into abort stack */ + sub r2, r2, #(CFG_GBL_DATA_SIZE+8) + /* get values for "aborted" pc and cpsr (into parm regs) */ + ldmia r2, {r2 - r3} + /* grab pointer to old stack */ + add r0, sp, #S_FRAME_SIZE + + add r5, sp, #S_SP + mov r1, lr + /* save sp_SVC, lr_SVC, pc, cpsr */ + stmia r5, {r0 - r3} + /* save current stack into r0 (param register) */ + mov r0, sp + .endm + + .macro get_bad_stack + /* setup our mode stack (enter in banked mode) */ + ldr r13, _armboot_start + /* move past malloc pool */ + sub r13, r13, #(CFG_MALLOC_LEN) + /* move to reserved a couple spots for abort stack */ + sub r13, r13, #(CFG_GBL_DATA_SIZE + 8) + + /* save caller lr in position 0 of saved stack */ + str lr, [r13] + /* get the spsr */ + mrs lr, spsr + /* save spsr in position 1 of saved stack */ + str lr, [r13, #4] + + /* prepare SVC-Mode */ + mov r13, #MODE_SVC + @ msr spsr_c, r13 + /* switch modes, make sure moves will execute */ + msr spsr, r13 + /* capture return pc */ + mov lr, pc + /* jump to next instruction & switch modes. */ + movs pc, lr + .endm + + .macro get_bad_stack_swi + /* space on current stack for scratch reg. */ + sub r13, r13, #4 + /* save R0's value. */ + str r0, [r13] + /* get data regions start */ + ldr r0, _armboot_start + /* move past malloc pool */ + sub r0, r0, #(CFG_MALLOC_LEN) + /* move past gbl and a couple spots for abort stack */ + sub r0, r0, #(CFG_GBL_DATA_SIZE + 8) + /* save caller lr in position 0 of saved stack */ + str lr, [r0] + /* get the spsr */ + mrs r0, spsr + /* save spsr in position 1 of saved stack */ + str lr, [r0, #4] + /* restore r0 */ + ldr r0, [r13] + /* pop stack entry */ + add r13, r13, #4 + .endm + +/* + * exception handlers + */ + .align 5 +undefined_instruction: + get_bad_stack + bad_save_user_regs + bl do_undefined_instruction + + .align 5 +software_interrupt: + get_bad_stack_swi + bad_save_user_regs + bl do_software_interrupt + + .align 5 +prefetch_abort: + get_bad_stack + bad_save_user_regs + bl do_prefetch_abort + + .align 5 +data_abort: + get_bad_stack + bad_save_user_regs + bl do_data_abort + + .align 5 +not_used: + get_bad_stack + bad_save_user_regs + bl do_not_used + + .align 5 +irq: + get_bad_stack + bad_save_user_regs + bl do_irq + + .align 5 +fiq: + get_bad_stack + bad_save_user_regs + bl do_fiq +#endif /* CONFIG_NAND_SPL */ |