/* * armboot - Startup Code for SA1100 CPU * * Copyright (C) 1998 Dan Malek * Copyright (C) 1999 Magnus Damm * Copyright (C) 2000 Wolfgang Denk * Copyright (c) 2001 Alex Züpke * * 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 #include /* ************************************************************************* * * 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 TEXT_BASE #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC) .globl _armboot_start _armboot_start: .word _start #endif /* * 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 #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) /* IRQ stack memory (calculated at run-time) + 8 bytes */ .globl IRQ_STACK_START_IN IRQ_STACK_START_IN: .word 0x0badc0de .globl _datarel_start _datarel_start: .word __datarel_start .globl _datarelrolocal_start _datarelrolocal_start: .word __datarelrolocal_start .globl _datarellocal_start _datarellocal_start: .word __datarellocal_start .globl _datarelro_start _datarelro_start: .word __datarelro_start .globl _got_start _got_start: .word __got_start .globl _got_end _got_end: .word __got_end /* * 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 /* * 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) 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 */ mov r7, r2 /* save addr of destination */ /* Set up the stack */ stack_setup: mov sp, r4 adr r0, _start ldr r2, _TEXT_BASE ldr r3, _bss_start sub r2, r3, r2 /* r2 <- size of armboot */ add r2, r0, r2 /* r2 <- source end address */ cmp r0, r6 beq clear_bss #ifndef CONFIG_SKIP_RELOCATE_UBOOT copy_loop: ldmia r0!, {r9-r10} /* copy from source address [r0] */ stmia r6!, {r9-r10} /* copy to target address [r1] */ cmp r0, r2 /* until source end address [r2] */ blo copy_loop #ifndef CONFIG_PRELOADER /* fix got entries */ ldr r1, _TEXT_BASE /* Text base */ mov r0, r7 /* reloc addr */ ldr r2, _got_start /* addr in Flash */ ldr r3, _got_end /* addr in Flash */ sub r3, r3, r1 add r3, r3, r0 sub r2, r2, r1 add r2, r2, r0 fixloop: ldr r4, [r2] sub r4, r4, r1 add r4, r4, r0 str r4, [r2] add r2, r2, #4 cmp r2, r3 bne fixloop #endif #endif /* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */ clear_bss: #ifndef CONFIG_PRELOADER ldr r0, _bss_start ldr r1, _bss_end ldr r3, _TEXT_BASE /* Text base */ mov r4, r7 /* reloc addr */ sub r0, r0, r3 add r0, r0, r4 sub r1, r1, r3 add r1, r1, r4 mov r2, #0x00000000 /* clear */ clbss_l:str r2, [r0] /* clear loop... */ add r0, r0, #4 cmp r0, r1 bne clbss_l #endif /* * We are done. Do not return, instead branch to second part of board * initialization, now running from RAM. */ ldr r0, _TEXT_BASE ldr r2, _board_init_r sub r2, r2, r0 add r2, r2, r7 /* position from board_init_r in RAM */ /* setup parameters for board_init_r */ mov r0, r5 /* gd_t */ mov r1, r7 /* dest_addr */ /* jump to it ... */ mov lr, r2 mov pc, lr _board_init_r: .word board_init_r #else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */ /* * the actual reset code */ reset: /* * set the cpu to SVC32 mode */ mrs r0,cpsr bic r0,r0,#0x1f orr r0,r0,#0x13 msr cpsr,r0 /* * we do sys-critical inits only at reboot, * not when booting from ram! */ #ifndef CONFIG_SKIP_LOWLEVEL_INIT bl cpu_init_crit #endif #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 address [r2] */ blo 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 */ bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ 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 blo clbss_l ldr pc, _start_armboot _start_armboot: .word start_armboot #endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */ /* ************************************************************************* * * CPU_init_critical registers * * setup important registers * setup memory timing * ************************************************************************* */ /* Interupt-Controller base address */ IC_BASE: .word 0x90050000 #define ICMR 0x04 /* Reset-Controller */ RST_BASE: .word 0x90030000 #define RSRR 0x00 #define RCSR 0x04 /* PWR */ PWR_BASE: .word 0x90020000 #define PSPR 0x08 #define PPCR 0x14 cpuspeed: .word CONFIG_SYS_CPUSPEED cpu_init_crit: /* * mask all IRQs */ ldr r0, IC_BASE mov r1, #0x00 str r1, [r0, #ICMR] /* set clock speed */ ldr r0, PWR_BASE ldr r1, cpuspeed str r1, [r0, #PPCR] /* * 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 /* * disable MMU stuff and enable I-cache */ mrc p15,0,r0,c1,c0 bic r0, r0, #0x00002000 @ clear bit 13 (X) bic r0, r0, #0x0000000f @ clear bits 3-0 (WCAM) orr r0, r0, #0x00001000 @ set bit 12 (I) Icache orr r0, r0, #0x00000002 @ set bit 2 (A) Align mcr p15,0,r0,c1,c0 /* * 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 */ 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 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC) 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 #else ldr r2, IRQ_STACK_START_IN #endif 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 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC) 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 #else ldr r13, IRQ_STACK_START_IN @ setup our mode stack #endif 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: ldr r0, RST_BASE mov r1, #0x0 @ set bit 3-0 ... str r1, [r0, #RCSR] @ ... to clear in RCSR mov r1, #0x1 str r1, [r0, #RSRR] @ and perform reset b reset_cpu @ silly, but repeat endlessly