| /* |
| * Early initialization code for ARMv7 architecture. |
| * |
| * This file is based off of the OMAP3530/ARM Cortex start.S file from Das |
| * U-Boot, which itself got the file from armboot. |
| * |
| * Copyright (c) 2004 Texas Instruments <r-woodruff2@ti.com> |
| * 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) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com> |
| * Copyright (c) 2013 The Chromium OS Authors |
| * |
| * 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; version 2 of |
| * the License. |
| * |
| * 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. |
| */ |
| |
| #include <arch/asm.h> |
| |
| .arm |
| /* |
| * Just in case the maskrom or the vendor basic firmware passes on a |
| * parameter when calling the bootblock, store it here for handling by C |
| * code. |
| */ |
| .section .bss, "aw" @nobits |
| .global maskrom_param |
| maskrom_param: |
| .word 0 |
| |
| ENTRY(_start) |
| /* |
| * Set the CPU to System mode with IRQ and FIQ disabled. Prefetch/Data |
| * aborts may happen early and crash before the abort handlers are |
| * installed, but at least the problem will show up near the code that |
| * causes it. |
| */ |
| msr cpsr_cxf, #0xdf |
| bl _thumb_start |
| ENDPROC(_start) |
| |
| .thumb |
| ENTRY(_thumb_start) |
| |
| /* Preserve the maskrom passed value, if any */ |
| mov r10, r0 |
| |
| bl arm_init_caches |
| |
| /* |
| * From Cortex-A Series Programmer's Guide: |
| * Only CPU 0 performs initialization. Other CPUs go into WFI |
| * to do this, first work out which CPU this is |
| * this code typically is run before any other initialization step |
| */ |
| mrc p15, 0, r1, c0, c0, 5 @ Read Multiprocessor Affinity Register |
| and r1, r1, #0x3 @ Extract CPU ID bits |
| cmp r1, #0 |
| bne wait_for_interrupt @ If this is not core0, wait |
| |
| /* |
| * Initialize the stack to a known value. This is used to check for |
| * stack overflow later in the boot process. |
| */ |
| ldr r0, =_stack |
| ldr r1, =_estack |
| ldr r2, =0xdeadbeef |
| init_stack_loop: |
| str r2, [r0] |
| add r0, #4 |
| cmp r0, r1 |
| bne init_stack_loop |
| |
| call_bootblock: |
| |
| /* Restore parameter passed in by maskrom/vendor firmware. */ |
| ldr r0, =maskrom_param |
| str r10, [r0] |
| |
| /* Set stackpointer in internal RAM to call bootblock main() */ |
| ldr sp, =_estack |
| ldr r0,=0x00000000 |
| /* |
| * The current design of cpu_info places the struct at the top of the |
| * stack. Free enough space to accommodate for that, but make sure it's |
| * 8-byte aligned for ABI compliance. |
| */ |
| sub sp, sp, #16 |
| bl main |
| |
| wait_for_interrupt: |
| wfi |
| mov pc, lr @ back to my caller |
| ENDPROC(_thumb_start) |