diff options
Diffstat (limited to 'cpu/ixp/start.S')
| -rw-r--r-- | cpu/ixp/start.S | 525 |
1 files changed, 0 insertions, 525 deletions
diff --git a/cpu/ixp/start.S b/cpu/ixp/start.S deleted file mode 100644 index 5ebce53..0000000 --- a/cpu/ixp/start.S +++ /dev/null @@ -1,525 +0,0 @@ -/* vi: set ts=8 sw=8 noet: */ -/* - * u-boot - Startup Code for XScale IXP - * - * Copyright (C) 2003 Kyle Harris <kharris@nexus-tech.net> - * - * Based on startup code example contained in the - * Intel IXP4xx Programmer's Guide and past u-boot Start.S - * samples. - * - * 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/arch/ixp425.h> - -#define MMU_Control_M 0x001 /* Enable MMU */ -#define MMU_Control_A 0x002 /* Enable address alignment faults */ -#define MMU_Control_C 0x004 /* Enable cache */ -#define MMU_Control_W 0x008 /* Enable write-buffer */ -#define MMU_Control_P 0x010 /* Compatability: 32 bit code */ -#define MMU_Control_D 0x020 /* Compatability: 32 bit data */ -#define MMU_Control_L 0x040 /* Compatability: */ -#define MMU_Control_B 0x080 /* Enable Big-Endian */ -#define MMU_Control_S 0x100 /* Enable system protection */ -#define MMU_Control_R 0x200 /* Enable ROM protection */ -#define MMU_Control_I 0x1000 /* Enable Instruction cache */ -#define MMU_Control_X 0x2000 /* Set interrupt vectors at 0xFFFF0000 */ -#define MMU_Control_Init (MMU_Control_P|MMU_Control_D|MMU_Control_L) - - -/* - * Macro definitions - */ - /* Delay a bit */ - .macro DELAY_FOR cycles, reg0 - ldr \reg0, =\cycles - subs \reg0, \reg0, #1 - subne pc, pc, #0xc - .endm - - /* wait for coprocessor write complete */ - .macro CPWAIT reg - mrc p15,0,\reg,c2,c0,0 - mov \reg,\reg - sub pc,pc,#4 - .endm - -.globl _start -_start: b reset - 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 - - .balignl 16,0xdeadbeef - - -/* - * Startup Code (reset vector) - * - * do important init only if we don't start from memory! - * - relocate armboot to ram - * - setup stack - * - jump to second stage - */ - -_TEXT_BASE: - .word TEXT_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 - -#ifdef CONFIG_USE_IRQ -/* IRQ stack memory (calculated at run-time) */ -.globl IRQ_STACK_START -IRQ_STACK_START: - .word 0x0badc0de - -/* IRQ stack memory (calculated at run-time) */ -.globl FIQ_STACK_START -FIQ_STACK_START: - .word 0x0badc0de -#endif - -/****************************************************************************/ -/* */ -/* the actual reset code */ -/* */ -/****************************************************************************/ - -reset: - /* disable mmu, set big-endian */ - mov r0, #0xf8 - mcr p15, 0, r0, c1, c0, 0 - CPWAIT r0 - - /* invalidate I & D caches & BTB */ - mcr p15, 0, r0, c7, c7, 0 - CPWAIT r0 - - /* invalidate I & Data TLB */ - mcr p15, 0, r0, c8, c7, 0 - CPWAIT r0 - - /* drain write and fill buffers */ - mcr p15, 0, r0, c7, c10, 4 - CPWAIT r0 - - /* disable write buffer coalescing */ - mrc p15, 0, r0, c1, c0, 1 - orr r0, r0, #1 - mcr p15, 0, r0, c1, c0, 1 - CPWAIT r0 - - /* set EXP CS0 to the optimum timing */ - ldr r1, =CONFIG_SYS_EXP_CS0 - ldr r2, =IXP425_EXP_CS0 - str r1, [r2] - - /* make sure flash is visible at 0 */ -#if 0 - ldr r2, =IXP425_EXP_CFG0 - ldr r1, [r2] - orr r1, r1, #0x80000000 - str r1, [r2] -#endif - mov r1, #CONFIG_SYS_SDR_CONFIG - ldr r2, =IXP425_SDR_CONFIG - str r1, [r2] - - /* disable refresh cycles */ - mov r1, #0 - ldr r3, =IXP425_SDR_REFRESH - str r1, [r3] - - /* send nop command */ - mov r1, #3 - ldr r4, =IXP425_SDR_IR - str r1, [r4] - DELAY_FOR 0x4000, r0 - - /* set SDRAM internal refresh val */ - ldr r1, =CONFIG_SYS_SDRAM_REFRESH_CNT - str r1, [r3] - DELAY_FOR 0x4000, r0 - - /* send precharge-all command to close all open banks */ - mov r1, #2 - str r1, [r4] - DELAY_FOR 0x4000, r0 - - /* provide 8 auto-refresh cycles */ - mov r1, #4 - mov r5, #8 -111: str r1, [r4] - DELAY_FOR 0x100, r0 - subs r5, r5, #1 - bne 111b - - /* set mode register in sdram */ - mov r1, #CONFIG_SYS_SDR_MODE_CONFIG - str r1, [r4] - DELAY_FOR 0x4000, r0 - - /* send normal operation command */ - mov r1, #6 - str r1, [r4] - DELAY_FOR 0x4000, r0 - - /* copy */ - mov r0, #0 - mov r4, r0 - add r2, r0, #CONFIG_SYS_MONITOR_LEN - mov r1, #0x10000000 - mov r5, r1 - - 30: - ldr r3, [r0], #4 - str r3, [r1], #4 - cmp r0, r2 - bne 30b - - /* invalidate I & D caches & BTB */ - mcr p15, 0, r0, c7, c7, 0 - CPWAIT r0 - - /* invalidate I & Data TLB */ - mcr p15, 0, r0, c8, c7, 0 - CPWAIT r0 - - /* drain write and fill buffers */ - mcr p15, 0, r0, c7, c10, 4 - CPWAIT r0 - - /* move flash to 0x50000000 */ - ldr r2, =IXP425_EXP_CFG0 - ldr r1, [r2] - bic r1, r1, #0x80000000 - str r1, [r2] - - nop - nop - nop - nop - nop - nop - - /* invalidate I & Data TLB */ - mcr p15, 0, r0, c8, c7, 0 - CPWAIT r0 - - /* enable I cache */ - mrc p15, 0, r0, c1, c0, 0 - orr r0, r0, #MMU_Control_I - mcr p15, 0, r0, c1, c0, 0 - CPWAIT r0 - - mrs r0,cpsr /* set the cpu to SVC32 mode */ - bic r0,r0,#0x1f /* (superviser mode, M=10011) */ - orr r0,r0,#0x13 - msr cpsr,r0 - -#ifndef CONFIG_SKIP_RELOCATE_UBOOT -relocate: /* relocate U-Boot to RAM */ - adr r0, _start /* r0 <- current position of code */ - ldr r1, _TEXT_BASE /* test if we run from flash or RAM */ - cmp r0, r1 /* don't reloc during debug */ - beq stack_setup - - ldr r2, _armboot_start - ldr r3, _bss_start - sub r2, r3, r2 /* r2 <- size of armboot */ - add r2, r0, r2 /* r2 <- source end address */ - -copy_loop: - ldmia r0!, {r3-r10} /* copy from source address [r0] */ - stmia r1!, {r3-r10} /* copy to target address [r1] */ - cmp r0, r2 /* until source end addreee [r2] */ - ble copy_loop -#endif /* CONFIG_SKIP_RELOCATE_UBOOT */ - - /* Set up the stack */ -stack_setup: - ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */ - sub r0, r0, #CONFIG_SYS_MALLOC_LEN /* malloc area */ - sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo */ -#ifdef CONFIG_USE_IRQ - sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ) -#endif - sub sp, r0, #12 /* leave 3 words for abort-stack */ - -clear_bss: - ldr r0, _bss_start /* find start of bss segment */ - ldr r1, _bss_end /* stop here */ - mov r2, #0x00000000 /* clear */ - -clbss_l:str r2, [r0] /* clear loop... */ - add r0, r0, #4 - cmp r0, r1 - ble clbss_l - - ldr pc, _start_armboot - -_start_armboot: .word start_armboot - - -/****************************************************************************/ -/* */ -/* 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 - - /* use bad_save_user_regs for abort/prefetch/undef/swi ... */ - - .macro bad_save_user_regs - sub sp, sp, #S_FRAME_SIZE - stmia sp, {r0 - r12} /* Calling r0-r12 */ - add r8, sp, #S_PC - - ldr r2, _armboot_start - sub r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN) - sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ set base 2 words into abort stack - ldmia r2, {r2 - r4} /* get pc, cpsr, old_r0 */ - add r0, sp, #S_FRAME_SIZE /* restore sp_SVC */ - - add r5, sp, #S_SP - mov r1, lr - stmia r5, {r0 - r4} /* save sp_SVC, lr_SVC, pc, cpsr, old_r */ - mov r0, sp - .endm - - - /* use irq_save_user_regs / irq_restore_user_regs for */ - /* IRQ/FIQ handling */ - - .macro irq_save_user_regs - sub sp, sp, #S_FRAME_SIZE - stmia sp, {r0 - r12} /* Calling r0-r12 */ - add r8, sp, #S_PC - stmdb r8, {sp, lr}^ /* Calling SP, LR */ - str lr, [r8, #0] /* Save calling PC */ - mrs r6, spsr - str r6, [r8, #4] /* Save CPSR */ - str r0, [r8, #8] /* Save OLD_R0 */ - mov r0, sp - .endm - - .macro irq_restore_user_regs - ldmia sp, {r0 - lr}^ @ Calling r0 - lr - mov r0, r0 - ldr lr, [sp, #S_PC] @ Get PC - add sp, sp, #S_FRAME_SIZE - subs pc, lr, #4 @ return & move spsr_svc into cpsr - .endm - - .macro get_bad_stack - ldr r13, _armboot_start @ setup our mode stack - sub r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN) - sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack - - str lr, [r13] @ save caller lr / spsr - mrs lr, spsr - str lr, [r13, #4] - - mov r13, #MODE_SVC @ prepare SVC-Mode - msr spsr_c, r13 - mov lr, pc - movs pc, lr - .endm - - .macro get_irq_stack @ setup IRQ stack - ldr sp, IRQ_STACK_START - .endm - - .macro get_fiq_stack @ setup FIQ stack - ldr sp, FIQ_STACK_START - .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 - 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 - -#ifdef CONFIG_USE_IRQ - - .align 5 -irq: - get_irq_stack - irq_save_user_regs - bl do_irq - irq_restore_user_regs - - .align 5 -fiq: - get_fiq_stack - irq_save_user_regs /* someone ought to write a more */ - bl do_fiq /* effiction fiq_save_user_regs */ - irq_restore_user_regs - -#else - - .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 - -/****************************************************************************/ -/* */ -/* Reset function: Use Watchdog to reset */ -/* */ -/****************************************************************************/ - - .align 5 -.globl reset_cpu - -reset_cpu: - ldr r1, =0x482e - ldr r2, =IXP425_OSWK - str r1, [r2] - ldr r1, =0x0fff - ldr r2, =IXP425_OSWT - str r1, [r2] - ldr r1, =0x5 - ldr r2, =IXP425_OSWE - str r1, [r2] - b reset_endless - - -reset_endless: - - b reset_endless - -#ifdef CONFIG_USE_IRQ - -.LC0: .word loops_per_jiffy - -/* - * 0 <= r0 <= 2000 - */ -.globl __udelay -__udelay: - mov r2, #0x6800 - orr r2, r2, #0x00db - mul r0, r2, r0 - ldr r2, .LC0 - ldr r2, [r2] @ max = 0x0fffffff - mov r0, r0, lsr #11 @ max = 0x00003fff - mov r2, r2, lsr #11 @ max = 0x0003ffff - mul r0, r2, r0 @ max = 2^32-1 - movs r0, r0, lsr #6 - -delay_loop: - subs r0, r0, #1 - bne delay_loop - mov pc, lr - -#endif /* CONFIG_USE_IRQ */ |