| /* |
| * armboot - Startup Code for ARM720 CPU-core |
| * |
| * Copyright (c) 2001 Marius Gröger <mag@sysgo.de> |
| * Copyright (c) 2002 Alex Züpke <azu@sysgo.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" |
| |
| |
| /* |
| ************************************************************************* |
| * |
| * Jump vector table as in table 3.1 in [1] |
| * |
| ************************************************************************* |
| */ |
| |
| |
| .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: |
| /* |
| * set the cpu to SVC32 mode |
| */ |
| mrs r0,cpsr |
| bic r0,r0,#0x1f |
| orr r0,r0,#0xd3 /* was 13 */ |
| msr cpsr,r0 |
| |
| #ifdef CONFIG_INIT_CRITICAL |
| /* scratch stack */ |
| /**** ldr r1, =0x00204000 ****/ |
| /* Insure word alignment */ |
| /**** bic r1, r1, #3 ****/ |
| /* Init stack SYS */ |
| /**** mov sp, r1 ****/ |
| /* |
| * This does a lot more than just set up the memory, which |
| * is why it's called lowlevelinit |
| */ |
| bl lowlevelinit /* in lowlevel.S */ |
| |
| /* |
| * Read/modify/write CP15 control register |
| * disable MMU, enable I-Cache, select Asychronous Clocking Mode |
| */ |
| |
| mrc p15, 0, r0, c1, c0, 0 @ read cp15 control register (cp15 r1) in r0 |
| bic r0, r0, #0x00002300 @ clear bits 13, 9:8 (--V- --RS) |
| bic r0, r0, #0x0000008f @ clear bits 7, 3:0 (B--- WCAM) |
| orr r0, r0, #0x00000002 @ set bit 2 (A) Align |
| orr r0, r0, #0x00000004 @ set bit 3 (C) D-Cache |
| orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache |
| orr r0, r0, #0xC0000000 @ set bits 31:30 (iA, nF) |
| mcr p15, 0, r0, c1, c0, 0 @ write r0 in cp15 control register (cp15 r1) |
| #endif /* CONFIG_INIT_CRITICAL */ |
| /* |
| * relocate exeception table |
| */ |
| ldr r0, =_start |
| ldr r1, =0x0 |
| mov r2, #16 |
| copyex: |
| subs r2, r2, #1 |
| ldr r3, [r0], #4 |
| str r3, [r1], #4 |
| bne copyex |
| |
| /* |
| * we do sys-critical inits only at reboot, |
| * not when booting from ram! |
| */ |
| #ifdef CONFIG_INIT_CRITICAL |
| bl cpu_init_crit |
| |
| 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_INIT_CRITICAL */ |
| |
| /* Set up the stack */ |
| stack_setup: |
| 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 */ |
| #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 |
| |
| /* |
| ************************************************************************* |
| * |
| * CPU_init_critical registers |
| * |
| ************************************************************************* |
| */ |
| |
| cpu_init_crit: |
| /* do nothing for now */ |
| mov pc, lr |
| |
| |
| /* |
| ************************************************************************* |
| * |
| * 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 ... |
| * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling |
| */ |
| |
| .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+CFG_MALLOC_LEN) |
| sub r2, r2, #(CFG_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 |
| |
| .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+CFG_MALLOC_LEN) |
| sub r13, r13, #(CFG_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 |
| /* someone ought to write a more effiction fiq_save_user_regs */ |
| irq_save_user_regs |
| bl do_fiq |
| 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 |
| |
| .align 5 |
| .globl reset_cpu |
| reset_cpu: |
| mov pc, r0 |