mirror of
https://github.com/AsahiLinux/u-boot
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3a0398d7b9
Most code can be shared between i.MX23 and i.MX28 as both are from i.MXS family; this source directory structure makes easy to share code among them. Signed-off-by: Otavio Salvador <otavio@ossystems.com.br> Acked-by: Stefano Babic <sbabic@denx.de>
247 lines
5.7 KiB
ArmAsm
247 lines
5.7 KiB
ArmAsm
/*
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* armboot - Startup Code for ARM926EJS CPU-core
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*
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* Copyright (c) 2003 Texas Instruments
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*
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* ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
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*
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* Copyright (c) 2001 Marius Groger <mag@sysgo.de>
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* Copyright (c) 2002 Alex Zupke <azu@sysgo.de>
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* Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
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* Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com>
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* Copyright (c) 2003 Kshitij <kshitij@ti.com>
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* Copyright (c) 2010 Albert Aribaud <albert.u.boot@aribaud.net>
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*
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* Change to support call back into iMX28 bootrom
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* Copyright (c) 2011 Marek Vasut <marek.vasut@gmail.com>
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* on behalf of DENX Software Engineering GmbH
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <asm-offsets.h>
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#include <config.h>
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#include <common.h>
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#include <version.h>
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/*
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*************************************************************************
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*
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* Jump vector table as in table 3.1 in [1]
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*
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*************************************************************************
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*/
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.globl _start
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_start:
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b reset
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b undefined_instruction
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b software_interrupt
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b prefetch_abort
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b data_abort
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b not_used
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b irq
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b fiq
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/*
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* Vector table, located at address 0x20.
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* This table allows the code running AFTER SPL, the U-Boot, to install it's
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* interrupt handlers here. The problem is that the U-Boot is loaded into RAM,
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* including it's interrupt vectoring table and the table at 0x0 is still the
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* SPLs. So if interrupt happens in U-Boot, the SPLs interrupt vectoring table
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* is still used.
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*/
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_vt_reset:
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.word _reset
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_vt_undefined_instruction:
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.word _hang
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_vt_software_interrupt:
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.word _hang
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_vt_prefetch_abort:
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.word _hang
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_vt_data_abort:
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.word _hang
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_vt_not_used:
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.word _reset
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_vt_irq:
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.word _hang
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_vt_fiq:
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.word _hang
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reset:
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ldr pc, _vt_reset
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undefined_instruction:
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ldr pc, _vt_undefined_instruction
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software_interrupt:
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ldr pc, _vt_software_interrupt
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prefetch_abort:
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ldr pc, _vt_prefetch_abort
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data_abort:
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ldr pc, _vt_data_abort
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not_used:
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ldr pc, _vt_not_used
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irq:
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ldr pc, _vt_irq
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fiq:
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ldr pc, _vt_fiq
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.balignl 16,0xdeadbeef
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/*
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*************************************************************************
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*
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* Startup Code (reset vector)
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*
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* do important init only if we don't start from memory!
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* setup Memory and board specific bits prior to relocation.
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* relocate armboot to ram
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* setup stack
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*
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*************************************************************************
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*/
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.globl _TEXT_BASE
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_TEXT_BASE:
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.word CONFIG_SYS_TEXT_BASE
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/*
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* These are defined in the board-specific linker script.
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* Subtracting _start from them lets the linker put their
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* relative position in the executable instead of leaving
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* them null.
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*/
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.globl _bss_start_ofs
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_bss_start_ofs:
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.word __bss_start - _start
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.globl _bss_end_ofs
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_bss_end_ofs:
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.word __bss_end__ - _start
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.globl _end_ofs
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_end_ofs:
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.word _end - _start
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#ifdef CONFIG_USE_IRQ
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/* IRQ stack memory (calculated at run-time) */
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.globl IRQ_STACK_START
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IRQ_STACK_START:
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.word 0x0badc0de
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/* IRQ stack memory (calculated at run-time) */
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.globl FIQ_STACK_START
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FIQ_STACK_START:
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.word 0x0badc0de
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#endif
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/* IRQ stack memory (calculated at run-time) + 8 bytes */
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.globl IRQ_STACK_START_IN
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IRQ_STACK_START_IN:
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.word 0x0badc0de
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/*
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* the actual reset code
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*/
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_reset:
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/*
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* Store all registers on old stack pointer, this will allow us later to
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* return to the BootROM and let the BootROM load U-Boot into RAM.
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*/
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push {r0-r12,r14}
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/* save control register c1 */
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mrc p15, 0, r0, c1, c0, 0
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push {r0}
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/*
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* set the cpu to SVC32 mode and store old CPSR register content
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*/
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mrs r0,cpsr
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push {r0}
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bic r0,r0,#0x1f
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orr r0,r0,#0xd3
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msr cpsr,r0
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/*
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* we do sys-critical inits only at reboot,
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* not when booting from ram!
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*/
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#ifndef CONFIG_SKIP_LOWLEVEL_INIT
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bl cpu_init_crit
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#endif
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bl board_init_ll
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/*
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* restore bootrom's cpu mode (especially FIQ)
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*/
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pop {r0}
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msr cpsr,r0
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/*
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* restore c1 register
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* (especially set exception vector location back to
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* bootrom space which is required by bootrom for USB boot)
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*/
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pop {r0}
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mcr p15, 0, r0, c1, c0, 0
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pop {r0-r12,r14}
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bx lr
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/*
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*************************************************************************
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*
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* CPU_init_critical registers
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*
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* setup important registers
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* setup memory timing
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*
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*************************************************************************
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*/
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#ifndef CONFIG_SKIP_LOWLEVEL_INIT
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cpu_init_crit:
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/*
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* flush v4 I/D caches
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*/
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mov r0, #0
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mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
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mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
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/*
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* disable MMU stuff and caches
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*/
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mrc p15, 0, r0, c1, c0, 0
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bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */
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bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */
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orr r0, r0, #0x00000002 /* set bit 2 (A) Align */
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orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */
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mcr p15, 0, r0, c1, c0, 0
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mov pc, lr /* back to my caller */
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.align 5
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#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
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_hang:
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ldr sp, _TEXT_BASE /* switch to abort stack */
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1:
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bl 1b /* hang and never return */
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