| /* 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 */ |