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Diffstat (limited to 'src/arch/armv7/init.S')
| -rw-r--r-- | src/arch/armv7/init.S | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/src/arch/armv7/init.S b/src/arch/armv7/init.S new file mode 100644 index 0000000000..033637e89a --- /dev/null +++ b/src/arch/armv7/init.S @@ -0,0 +1,94 @@ +/* + * 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; 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 + */ + +#define __ASSEMBLY__ +#include <system.h> + +.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 +_pad: .word 0x12345678 /* now 16*4=64 */ + + .balignl 16,0xdeadbeef + +reset: + /* + * set the cpu to SVC32 mode + */ + mrs r0, cpsr + bic r0, r0, #0x1f + orr r0, r0, #0xd3 + msr cpsr,r0 + + /* + * 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 + + /* Set V=0 in CP15 SCTRL register - for VBAR to point to vector */ + mrc p15, 0, r0, c1, c0, 0 @ Read CP15 SCTRL Register + bic r0, #CR_V @ V = 0 + mcr p15, 0, r0, c1, c0, 0 @ Write CP15 SCTRL Register + + /* Set vector address in CP15 VBAR register */ + ldr r0, =_start + mcr p15, 0, r0, c12, c0, 0 @Set VBAR + +/* Set stackpointer in internal RAM to call board_init_f */ +call_board_init_f: + ldr sp, =(CONFIG_SYS_INIT_SP_ADDR) + mov sp, r0 + bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ + ldr r0,=0x00000000 + bl board_init_f + +wait_for_interrupt: + wfi + mov pc, lr @ back to my caller |