u-boot/arch/arm/cpu/arm926ejs/spear/start.S

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/*
* 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>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
/*
*************************************************************************
*
* Startup Code (reset vector)
*
* Below are the critical initializations already taken place in BootROM.
* So, these are not taken care in Xloader
* 1. Relocation to RAM
* 2. Initializing stacks
*
*************************************************************************
*/
.globl reset
reset:
/*
* Xloader has to return back to BootROM in a few cases.
* eg. Ethernet boot, UART boot, USB boot
* Saving registers for returning back
*/
stmdb sp!, {r0-r12,r14}
bl cpu_init_crit
/*
* Clearing bss area is not done in Xloader.
* BSS area lies in the DDR location which is not yet initialized
* bss is assumed to be uninitialized.
*/
bl spl_boot
ldmia sp!, {r0-r12,pc}
/*
*************************************************************************
*
* CPU_init_critical registers
*
* setup important registers
* setup memory timing
*
*************************************************************************
*/
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 */
/*
* enable instruction cache
*/
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */
mcr p15, 0, r0, c1, c0, 0
/*
* Go setup Memory and board specific bits prior to relocation.
*/
stmdb sp!, {lr}
bl lowlevel_init /* go setup pll,mux,memory */
ldmia sp!, {pc}