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Diffstat (limited to 'board/denx/m28evk/start.S')
| -rw-r--r-- | board/denx/m28evk/start.S | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/board/denx/m28evk/start.S b/board/denx/m28evk/start.S new file mode 100644 index 0000000000..94696d6cdc --- /dev/null +++ b/board/denx/m28evk/start.S @@ -0,0 +1,234 @@ +/* + * armboot - Startup Code for ARM926EJS CPU-core + * + * Copyright (c) 2003 Texas Instruments + * + * ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------ + * + * Copyright (c) 2001 Marius Groger <mag@sysgo.de> + * Copyright (c) 2002 Alex Zupke <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> + * + * Change to support call back into iMX28 bootrom + * Copyright (c) 2011 Marek Vasut <marek.vasut@gmail.com> + * on behalf of DENX Software Engineering GmbH + * + * 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 <common.h> +#include <version.h> + +#if defined(CONFIG_OMAP1610) +#include <./configs/omap1510.h> +#elif defined(CONFIG_OMAP730) +#include <./configs/omap730.h> +#endif + +/* + ************************************************************************* + * + * Jump vector table as in table 3.1 in [1] + * + ************************************************************************* + */ + + +.globl _start +_start: + b reset + b undefined_instruction + b software_interrupt + b prefetch_abort + b data_abort + b not_used + b irq + b fiq + +/* + * Vector table, located at address 0x20. + * This table allows the code running AFTER SPL, the U-Boot, to install it's + * interrupt handlers here. The problem is that the U-Boot is loaded into RAM, + * including it's interrupt vectoring table and the table at 0x0 is still the + * SPLs. So if interrupt happens in U-Boot, the SPLs interrupt vectoring table + * is still used. + */ +_vt_reset: + .word _reset +_vt_undefined_instruction: + .word _hang +_vt_software_interrupt: + .word _hang +_vt_prefetch_abort: + .word _hang +_vt_data_abort: + .word _hang +_vt_not_used: + .word _reset +_vt_irq: + .word _hang +_vt_fiq: + .word _hang + +reset: + ldr pc, _vt_reset +undefined_instruction: + ldr pc, _vt_undefined_instruction +software_interrupt: + ldr pc, _vt_software_interrupt +prefetch_abort: + ldr pc, _vt_prefetch_abort +data_abort: + ldr pc, _vt_data_abort +not_used: + ldr pc, _vt_not_used +irq: + ldr pc, _vt_irq +fiq: + ldr pc, _vt_fiq + + .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 + * + ************************************************************************* + */ + +.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: + /* + * Store all registers on old stack pointer, this will allow us later to + * return to the BootROM and let the BootROM load U-Boot into RAM. + */ + push {r0-r12,r14} + + /* + * 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 board_init_ll + + pop {r0-r12,r14} + bx lr + +/* + ************************************************************************* + * + * CPU_init_critical registers + * + * setup important registers + * setup memory timing + * + ************************************************************************* + */ +#ifndef CONFIG_SKIP_LOWLEVEL_INIT +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 */ + mcr p15, 0, r0, c1, c0, 0 + + mov pc, lr /* back to my caller */ + + .align 5 +#endif /* CONFIG_SKIP_LOWLEVEL_INIT */ + +_hang: + ldr sp, _TEXT_BASE /* switch to abort stack */ +1: + bl 1b /* hang and never return */ |