u-boot/arch/arm/cpu/pxa/start.S

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/* SPDX-License-Identifier: GPL-2.0+ */
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/*
* armboot - Startup Code for XScale CPU-core
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*
* Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
* Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
* Copyright (C) 2000 Wolfgang Denk <wd@denx.de>
* Copyright (C) 2001 Alex Zuepke <azu@sysgo.de>
* 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) 2002 Kyle Harris <kharris@nexus-tech.net>
* Copyright (C) 2003 Kai-Uwe Bloem <kai-uwe.bloem@auerswald.de>
* Copyright (C) 2003 Kshitij <kshitij@ti.com>
* Copyright (C) 2003 Richard Woodruff <r-woodruff2@ti.com>
* Copyright (C) 2003 Robert Schwebel <r.schwebel@pengutronix.de>
* Copyright (C) 2004 Texas Instruments <r-woodruff2@ti.com>
* Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
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*/
#include <asm-offsets.h>
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#include <config.h>
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/*
*************************************************************************
*
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* 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
*
*************************************************************************
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*/
.globl reset
reset:
/*
* set the cpu to SVC32 mode
*/
mrs r0,cpsr
bic r0,r0,#0x1f
orr r0,r0,#0xd3
msr cpsr,r0
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
bl cpu_init_crit
#endif
#ifdef CONFIG_CPU_PXA25X
bl lock_cache_for_stack
#endif
#ifdef CONFIG_CPU_PXA27X
/*
* enable clock for SRAM
*/
ldr r0,=CKEN
ldr r1,[r0]
orr r1,r1,#(1 << 20)
str r1,[r0]
#endif
bl _main
/*------------------------------------------------------------------------------*/
.globl c_runtime_cpu_setup
c_runtime_cpu_setup:
#ifdef CONFIG_CPU_PXA25X
/*
* Unlock (actually, disable) the cache now that board_init_f
* is done. We could do this earlier but we would need to add
* a new C runtime hook, whereas c_runtime_cpu_setup already
* exists.
* As this routine is just a call to cpu_init_crit, let us
* tail-optimize and do a simple branch here.
*/
b cpu_init_crit
#else
bx lr
#endif
/*
*************************************************************************
*
* CPU_init_critical registers
*
* setup important registers
* setup memory timing
*
*************************************************************************
*/
#if !defined(CONFIG_SKIP_LOWLEVEL_INIT) || defined(CONFIG_CPU_PXA25X)
cpu_init_crit:
/*
* flush v4 I/D caches
*/
mov r0, #0
mcr p15, 0, r0, c7, c7, 0 /* Invalidate I+D+BTB caches */
mcr p15, 0, r0, c8, c7, 0 /* Invalidate Unified TLB */
/*
* disable MMU stuff and caches
*/
mrc p15, 0, r0, c1, c0, 0
bic r0, r0, #0x00003300 @ clear bits 13:12, 9:8 (--VI --RS)
bic r0, r0, #0x00000087 @ clear bits 7, 2:0 (B--- -CAM)
orr r0, r0, #0x00000002 @ set bit 1 (A) Align
mcr p15, 0, r0, c1, c0, 0
mov pc, lr /* back to my caller */
#endif /* !CONFIG_SKIP_LOWLEVEL_INIT || CONFIG_CPU_PXA25X */
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/*
* Enable MMU to use DCache as DRAM.
*
* This is useful on PXA25x and PXA26x in early bootstages, where there is no
* other possible memory available to hold stack.
*/
#ifdef CONFIG_CPU_PXA25X
.macro CPWAIT reg
mrc p15, 0, \reg, c2, c0, 0
mov \reg, \reg
sub pc, pc, #4
.endm
lock_cache_for_stack:
/* Domain access -- enable for all CPs */
ldr r0, =0x0000ffff
mcr p15, 0, r0, c3, c0, 0
/* Point TTBR to MMU table */
ldr r0, =mmutable
mcr p15, 0, r0, c2, c0, 0
/* Kick in MMU, ICache, DCache, BTB */
mrc p15, 0, r0, c1, c0, 0
bic r0, #0x1b00
bic r0, #0x0087
orr r0, #0x1800
orr r0, #0x0005
mcr p15, 0, r0, c1, c0, 0
CPWAIT r0
/* Unlock Icache, Dcache */
mcr p15, 0, r0, c9, c1, 1
mcr p15, 0, r0, c9, c2, 1
/* Flush Icache, Dcache, BTB */
mcr p15, 0, r0, c7, c7, 0
/* Unlock I-TLB, D-TLB */
mcr p15, 0, r0, c10, c4, 1
mcr p15, 0, r0, c10, c8, 1
/* Flush TLB */
mcr p15, 0, r0, c8, c7, 0
/* Allocate 4096 bytes of Dcache as RAM */
/* Drain pending loads and stores */
mcr p15, 0, r0, c7, c10, 4
mov r4, #0x00
mov r5, #0x00
mov r2, #0x01
mcr p15, 0, r0, c9, c2, 0
CPWAIT r0
/* 128 lines reserved (128 x 32bytes = 4096 bytes total) */
mov r0, #128
ldr r1, =0xfffff000
alloc:
mcr p15, 0, r1, c7, c2, 5
/* Drain pending loads and stores */
mcr p15, 0, r0, c7, c10, 4
strd r4, [r1], #8
strd r4, [r1], #8
strd r4, [r1], #8
strd r4, [r1], #8
subs r0, #0x01
bne alloc
/* Drain pending loads and stores */
mcr p15, 0, r0, c7, c10, 4
mov r2, #0x00
mcr p15, 0, r2, c9, c2, 0
CPWAIT r0
mov pc, lr
.section .mmutable, "a"
mmutable:
.align 14
/* 0x00000000 - 0xffe00000 : 1:1, uncached mapping */
.set __base, 0
.rept 0xfff
.word (__base << 20) | 0xc12
.set __base, __base + 1
.endr
/* 0xfff00000 : 1:1, cached mapping */
.word (0xfff << 20) | 0x1c1e
#endif /* CONFIG_CPU_PXA25X */