diff options
Diffstat (limited to 'roms/u-boot/arch/arm/cpu/arm926ejs/start.S')
| -rw-r--r-- | roms/u-boot/arch/arm/cpu/arm926ejs/start.S | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/roms/u-boot/arch/arm/cpu/arm926ejs/start.S b/roms/u-boot/arch/arm/cpu/arm926ejs/start.S new file mode 100644 index 00000000..07173270 --- /dev/null +++ b/roms/u-boot/arch/arm/cpu/arm926ejs/start.S @@ -0,0 +1,372 @@ +/* + * armboot - Startup Code for ARM926EJS CPU-core + * + * Copyright (c) 2003 Texas Instruments + * + * ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------ + * + * Copyright (c) 2001 Marius Gröger <mag@sysgo.de> + * Copyright (c) 2002 Alex Züpke <azu@sysgo.de> + * Copyright (c) 2002 Gary Jennejohn <garyj@denx.de> + * Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com> + * Copyright (c) 2003 Kshitij <kshitij@ti.com> + * Copyright (c) 2010 Albert Aribaud <albert.u.boot@aribaud.net> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <asm-offsets.h> +#include <config.h> +#include <common.h> +#include <version.h> + +/* + ************************************************************************* + * + * Jump vector table as in table 3.1 in [1] + * + ************************************************************************* + */ + + +#ifdef CONFIG_SYS_DV_NOR_BOOT_CFG +.globl _start +_start: +.globl _NOR_BOOT_CFG +_NOR_BOOT_CFG: + .word CONFIG_SYS_DV_NOR_BOOT_CFG + b reset +#else +.globl _start +_start: + b reset +#endif +#ifdef CONFIG_SPL_BUILD +/* No exception handlers in preloader */ + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + +_hang: + .word do_hang +/* pad to 64 byte boundary */ + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 +#else + 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 + +#endif /* CONFIG_SPL_BUILD */ + .balignl 16,0xdeadbeef + + +/* + ************************************************************************* + * + * Startup Code (reset vector) + * + * do important init only if we don't start from memory! + * setup Memory and board specific bits prior to relocation. + * relocate armboot to ram + * setup stack + * + ************************************************************************* + */ + +#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 + + /* + * we do sys-critical inits only at reboot, + * not when booting from ram! + */ +#ifndef CONFIG_SKIP_LOWLEVEL_INIT + bl cpu_init_crit +#endif + + bl _main + +/*------------------------------------------------------------------------------*/ + + .globl c_runtime_cpu_setup +c_runtime_cpu_setup: + + bx lr + +/* + ************************************************************************* + * + * CPU_init_critical registers + * + * setup important registers + * setup memory timing + * + ************************************************************************* + */ +#ifndef CONFIG_SKIP_LOWLEVEL_INIT +cpu_init_crit: + /* + * flush D cache before disabling it + */ + mov r0, #0 +flush_dcache: + mrc p15, 0, r15, c7, c10, 3 + bne flush_dcache + + mcr p15, 0, r0, c8, c7, 0 /* invalidate TLB */ + mcr p15, 0, r0, c7, c5, 0 /* invalidate I Cache */ + + /* + * disable MMU and D cache + * enable I cache if CONFIG_SYS_ICACHE_OFF is not defined + */ + mrc p15, 0, r0, c1, c0, 0 + bic r0, r0, #0x00000300 /* clear bits 9:8 (---- --RS) */ + bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */ +#ifdef CONFIG_SYS_EXCEPTION_VECTORS_HIGH + orr r0, r0, #0x00002000 /* set bit 13 (--V- ----) */ +#else + bic r0, r0, #0x00002000 /* clear bit 13 (--V- ----) */ +#endif + orr r0, r0, #0x00000002 /* set bit 2 (A) Align */ +#ifndef CONFIG_SYS_ICACHE_OFF + orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */ +#endif + mcr p15, 0, r0, c1, c0, 0 + + /* + * Go setup Memory and board specific bits prior to relocation. + */ + mov ip, lr /* perserve link reg across call */ + bl lowlevel_init /* go setup pll,mux,memory */ + mov lr, ip /* restore link */ + mov pc, lr /* back to my caller */ +#endif /* CONFIG_SKIP_LOWLEVEL_INIT */ + +#ifndef CONFIG_SPL_BUILD +/* + ************************************************************************* + * + * 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 + @ carve out a frame on current user stack + sub sp, sp, #S_FRAME_SIZE + stmia sp, {r0 - r12} @ Save user registers (now in svc mode) r0-r12 + ldr r2, IRQ_STACK_START_IN + @ get values for "aborted" pc and cpsr (into parm regs) + ldmia r2, {r2 - r3} + add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack + add r5, sp, #S_SP + mov r1, lr + stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr + mov r0, sp @ save current stack into r0 (param register) + .endm + + .macro irq_save_user_regs + sub sp, sp, #S_FRAME_SIZE + stmia sp, {r0 - r12} @ Calling r0-r12 + @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good. + 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 in position 0 of saved stack + mrs lr, spsr @ get the spsr + str lr, [r13, #4] @ save spsr in position 1 of saved stack + mov r13, #MODE_SVC @ prepare SVC-Mode + @ msr spsr_c, r13 + msr spsr, r13 @ switch modes, make sure moves will execute + mov lr, pc @ capture return pc + movs pc, lr @ jump to next instruction & switch modes. + .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 +#endif /* CONFIG_SPL_BUILD */ + +/* + * exception handlers + */ +#ifdef CONFIG_SPL_BUILD + .align 5 +do_hang: +1: + bl 1b /* hang and never return */ +#else /* !CONFIG_SPL_BUILD */ + .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 +#endif /* CONFIG_SPL_BUILD */ |