| /* |
| * armboot - Startup Code for ARM920 CPU-core |
| * |
| * Copyright (c) 2001 Marius Gröger <mag@sysgo.de> |
| * Copyright (c) 2002 Alex Züpke <azu@sysgo.de> |
| * Copyright (c) 2002 Gary Jennejohn <garyj@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 |
| */ |
| |
| #include <asm-offsets.h> |
| #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 |
| * |
| ************************************************************************* |
| */ |
| |
| .globl _TEXT_BASE |
| _TEXT_BASE: |
| .word CONFIG_SYS_TEXT_BASE |
| |
| /* |
| * These are defined in the board-specific linker script. |
| * Subtracting _start from them lets the linker put their |
| * relative position in the executable instead of leaving |
| * them null. |
| */ |
| .globl _bss_start_ofs |
| _bss_start_ofs: |
| .word __bss_start - _start |
| |
| .globl _bss_end_ofs |
| _bss_end_ofs: |
| .word __bss_end__ - _start |
| |
| .globl _end_ofs |
| _end_ofs: |
| .word _end - _start |
| |
| #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 |
| |
| /* IRQ stack memory (calculated at run-time) + 8 bytes */ |
| .globl IRQ_STACK_START_IN |
| IRQ_STACK_START_IN: |
| .word 0x0badc0de |
| |
| /* |
| * the actual reset code |
| */ |
| |
| reset: |
| /* |
| * set the cpu to SVC32 mode |
| */ |
| mrs r0,cpsr |
| bic r0,r0,#0x1f |
| orr r0,r0,#0xd3 |
| msr cpsr,r0 |
| |
| #define pWDTCTL 0x80001400 /* Watchdog Timer control register */ |
| #define pINTENC 0x8000050C /* Interrupt-Controller enable clear register */ |
| #define pCLKSET 0x80000420 /* clock divisor register */ |
| |
| /* disable watchdog, set watchdog control register to |
| * all zeros (default reset) |
| */ |
| ldr r0, =pWDTCTL |
| mov r1, #0x0 |
| str r1, [r0] |
| |
| /* |
| * mask all IRQs by setting all bits in the INTENC register (default) |
| */ |
| mov r1, #0xffffffff |
| ldr r0, =pINTENC |
| str r1, [r0] |
| |
| /* FCLK:HCLK:PCLK = 1:2:2 */ |
| /* default FCLK is 200 MHz, using 14.7456 MHz fin */ |
| ldr r0, =pCLKSET |
| ldr r1, =0x0004ee39 |
| @ ldr r1, =0x0005ee39 @ 1: 2: 4 |
| str r1, [r0] |
| |
| /* |
| * we do sys-critical inits only at reboot, |
| * not when booting from ram! |
| */ |
| #ifndef CONFIG_SKIP_LOWLEVEL_INIT |
| bl cpu_init_crit |
| #endif |
| |
| /* Set stackpointer in internal RAM to call board_init_f */ |
| call_board_init_f: |
| ldr sp, =(CONFIG_SYS_INIT_SP_ADDR) |
| bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ |
| ldr r0,=0x00000000 |
| bl board_init_f |
| |
| /*------------------------------------------------------------------------------*/ |
| |
| /* |
| * void relocate_code (addr_sp, gd, addr_moni) |
| * |
| * This "function" does not return, instead it continues in RAM |
| * after relocating the monitor code. |
| * |
| */ |
| .globl relocate_code |
| relocate_code: |
| mov r4, r0 /* save addr_sp */ |
| mov r5, r1 /* save addr of gd */ |
| mov r6, r2 /* save addr of destination */ |
| |
| /* Set up the stack */ |
| stack_setup: |
| mov sp, r4 |
| |
| adr r0, _start |
| cmp r0, r6 |
| beq clear_bss /* skip relocation */ |
| mov r1, r6 /* r1 <- scratch for copy_loop */ |
| ldr r3, _bss_start_ofs |
| add r2, r0, r3 /* r2 <- source end address */ |
| |
| copy_loop: |
| ldmia r0!, {r9-r10} /* copy from source address [r0] */ |
| stmia r1!, {r9-r10} /* copy to target address [r1] */ |
| cmp r0, r2 /* until source end address [r2] */ |
| blo copy_loop |
| |
| #ifndef CONFIG_SPL_BUILD |
| /* |
| * fix .rel.dyn relocations |
| */ |
| ldr r0, _TEXT_BASE /* r0 <- Text base */ |
| sub r9, r6, r0 /* r9 <- relocation offset */ |
| ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */ |
| add r10, r10, r0 /* r10 <- sym table in FLASH */ |
| ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */ |
| add r2, r2, r0 /* r2 <- rel dyn start in FLASH */ |
| ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */ |
| add r3, r3, r0 /* r3 <- rel dyn end in FLASH */ |
| fixloop: |
| ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */ |
| add r0, r0, r9 /* r0 <- location to fix up in RAM */ |
| ldr r1, [r2, #4] |
| and r7, r1, #0xff |
| cmp r7, #23 /* relative fixup? */ |
| beq fixrel |
| cmp r7, #2 /* absolute fixup? */ |
| beq fixabs |
| /* ignore unknown type of fixup */ |
| b fixnext |
| fixabs: |
| /* absolute fix: set location to (offset) symbol value */ |
| mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */ |
| add r1, r10, r1 /* r1 <- address of symbol in table */ |
| ldr r1, [r1, #4] /* r1 <- symbol value */ |
| add r1, r1, r9 /* r1 <- relocated sym addr */ |
| b fixnext |
| fixrel: |
| /* relative fix: increase location by offset */ |
| ldr r1, [r0] |
| add r1, r1, r9 |
| fixnext: |
| str r1, [r0] |
| add r2, r2, #8 /* each rel.dyn entry is 8 bytes */ |
| cmp r2, r3 |
| blo fixloop |
| #endif |
| |
| clear_bss: |
| #ifndef CONFIG_SPL_BUILD |
| ldr r0, _bss_start_ofs |
| ldr r1, _bss_end_ofs |
| mov r4, r6 /* reloc addr */ |
| add r0, r0, r4 |
| add r1, r1, r4 |
| mov r2, #0x00000000 /* clear */ |
| |
| clbss_l:cmp r0, r1 /* clear loop... */ |
| bhs clbss_e /* if reached end of bss, exit */ |
| str r2, [r0] |
| add r0, r0, #4 |
| b clbss_l |
| clbss_e: |
| #endif |
| |
| /* |
| * We are done. Do not return, instead branch to second part of board |
| * initialization, now running from RAM. |
| */ |
| ldr r0, _board_init_r_ofs |
| adr r1, _start |
| add lr, r0, r1 |
| add lr, lr, r9 |
| /* setup parameters for board_init_r */ |
| mov r0, r5 /* gd_t */ |
| mov r1, r6 /* dest_addr */ |
| /* jump to it ... */ |
| mov pc, lr |
| |
| _board_init_r_ofs: |
| .word board_init_r - _start |
| |
| _rel_dyn_start_ofs: |
| .word __rel_dyn_start - _start |
| _rel_dyn_end_ofs: |
| .word __rel_dyn_end - _start |
| _dynsym_start_ofs: |
| .word __dynsym_start - _start |
| |
| /* |
| ************************************************************************* |
| * |
| * CPU_init_critical registers |
| * |
| * setup important registers |
| * setup memory timing |
| * |
| ************************************************************************* |
| */ |
| |
| |
| cpu_init_crit: |
| /* |
| * 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 |
| orr r0, r0, #0x40000000 @ set bit 30 (nF) notFastBus |
| mcr p15, 0, r0, c1, c0, 0 |
| |
| |
| /* |
| * before relocating, we have to setup RAM timing |
| * because memory timing is board-dependend, you will |
| * find a lowlevel_init.S in your board directory. |
| */ |
| mov ip, lr |
| bl lowlevel_init |
| mov lr, ip |
| |
| 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 |
| ldr r2, IRQ_STACK_START_IN |
| ldmia r2, {r2 - r3} @ get pc, cpsr |
| add r0, sp, #S_FRAME_SIZE @ restore sp_SVC |
| |
| add r5, sp, #S_SP |
| mov r1, lr |
| stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr |
| 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, IRQ_STACK_START_IN @ setup our mode 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 |
| msr spsr, 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: |
| bl disable_interrupts |
| |
| /* Disable watchdog */ |
| ldr r1, =pWDTCTL |
| mov r3, #0 |
| str r3, [r1] |
| |
| /* reset counter */ |
| ldr r3, =0x00001984 |
| str r3, [r1, #4] |
| |
| /* Enable the watchdog */ |
| mov r3, #1 |
| str r3, [r1] |
| |
| _loop_forever: |
| b _loop_forever |