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      1 /* SPDX-License-Identifier: GPL-2.0+ */
      2 /*
      3  *  armboot - Startup Code for XScale CPU-core
      4  *
      5  *  Copyright (C) 1998	Dan Malek <dmalek (at) jlc.net>
      6  *  Copyright (C) 1999	Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
      7  *  Copyright (C) 2000	Wolfgang Denk <wd (at) denx.de>
      8  *  Copyright (C) 2001	Alex Zuepke <azu (at) sysgo.de>
      9  *  Copyright (C) 2001	Marius Groger <mag (at) sysgo.de>
     10  *  Copyright (C) 2002	Alex Zupke <azu (at) sysgo.de>
     11  *  Copyright (C) 2002	Gary Jennejohn <garyj (at) denx.de>
     12  *  Copyright (C) 2002	Kyle Harris <kharris (at) nexus-tech.net>
     13  *  Copyright (C) 2003	Kai-Uwe Bloem <kai-uwe.bloem (at) auerswald.de>
     14  *  Copyright (C) 2003	Kshitij <kshitij (at) ti.com>
     15  *  Copyright (C) 2003	Richard Woodruff <r-woodruff2 (at) ti.com>
     16  *  Copyright (C) 2003	Robert Schwebel <r.schwebel (at) pengutronix.de>
     17  *  Copyright (C) 2004	Texas Instruments <r-woodruff2 (at) ti.com>
     18  *  Copyright (C) 2010	Marek Vasut <marek.vasut (at) gmail.com>
     19  */
     20 
     21 #include <asm-offsets.h>
     22 #include <config.h>
     23 
     24 /*
     25  *************************************************************************
     26  *
     27  * Startup Code (reset vector)
     28  *
     29  * do important init only if we don't start from memory!
     30  * setup Memory and board specific bits prior to relocation.
     31  * relocate armboot to ram
     32  * setup stack
     33  *
     34  *************************************************************************
     35  */
     36 
     37 	.globl	reset
     38 
     39 reset:
     40 	/*
     41 	 * set the cpu to SVC32 mode
     42 	 */
     43 	mrs	r0,cpsr
     44 	bic	r0,r0,#0x1f
     45 	orr	r0,r0,#0xd3
     46 	msr	cpsr,r0
     47 
     48 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
     49 	bl  cpu_init_crit
     50 #endif
     51 
     52 #ifdef	CONFIG_CPU_PXA25X
     53 	bl	lock_cache_for_stack
     54 #endif
     55 #ifdef	CONFIG_CPU_PXA27X
     56 	/*
     57 	 * enable clock for SRAM
     58 	 */
     59 	ldr	r0,=CKEN
     60 	ldr	r1,[r0]
     61 	orr	r1,r1,#(1 << 20)
     62 	str	r1,[r0]
     63 #endif
     64 	bl	_main
     65 
     66 /*------------------------------------------------------------------------------*/
     67 
     68 	.globl	c_runtime_cpu_setup
     69 c_runtime_cpu_setup:
     70 
     71 #ifdef CONFIG_CPU_PXA25X
     72 	/*
     73 	 * Unlock (actually, disable) the cache now that board_init_f
     74 	 * is done. We could do this earlier but we would need to add
     75 	 * a new C runtime hook, whereas c_runtime_cpu_setup already
     76 	 * exists.
     77 	 * As this routine is just a call to cpu_init_crit, let us
     78 	 * tail-optimize and do a simple branch here.
     79 	 */
     80 	b	cpu_init_crit
     81 #else
     82 	bx	lr
     83 #endif
     84 
     85 /*
     86  *************************************************************************
     87  *
     88  * CPU_init_critical registers
     89  *
     90  * setup important registers
     91  * setup memory timing
     92  *
     93  *************************************************************************
     94  */
     95 #if !defined(CONFIG_SKIP_LOWLEVEL_INIT) || defined(CONFIG_CPU_PXA25X)
     96 cpu_init_crit:
     97 	/*
     98 	 * flush v4 I/D caches
     99 	 */
    100 	mov	r0, #0
    101 	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
    102 	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
    103 
    104 	/*
    105 	 * disable MMU stuff and caches
    106 	 */
    107 	mrc	p15, 0, r0, c1, c0, 0
    108 	bic	r0, r0, #0x00003300	@ clear bits 13:12, 9:8 (--VI --RS)
    109 	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
    110 	orr	r0, r0, #0x00000002	@ set bit 1 (A) Align
    111 	mcr	p15, 0, r0, c1, c0, 0
    112 
    113 	mov	pc, lr		/* back to my caller */
    114 #endif /* !CONFIG_SKIP_LOWLEVEL_INIT || CONFIG_CPU_PXA25X */
    115 
    116 /*
    117  * Enable MMU to use DCache as DRAM.
    118  *
    119  * This is useful on PXA25x and PXA26x in early bootstages, where there is no
    120  * other possible memory available to hold stack.
    121  */
    122 #ifdef CONFIG_CPU_PXA25X
    123 .macro CPWAIT reg
    124 	mrc	p15, 0, \reg, c2, c0, 0
    125 	mov	\reg, \reg
    126 	sub	pc, pc, #4
    127 .endm
    128 lock_cache_for_stack:
    129 	/* Domain access -- enable for all CPs */
    130 	ldr	r0, =0x0000ffff
    131 	mcr	p15, 0, r0, c3, c0, 0
    132 
    133 	/* Point TTBR to MMU table */
    134 	ldr	r0, =mmutable
    135 	mcr	p15, 0, r0, c2, c0, 0
    136 
    137 	/* Kick in MMU, ICache, DCache, BTB */
    138 	mrc	p15, 0, r0, c1, c0, 0
    139 	bic	r0, #0x1b00
    140 	bic	r0, #0x0087
    141 	orr	r0, #0x1800
    142 	orr	r0, #0x0005
    143 	mcr	p15, 0, r0, c1, c0, 0
    144 	CPWAIT	r0
    145 
    146 	/* Unlock Icache, Dcache */
    147 	mcr	p15, 0, r0, c9, c1, 1
    148 	mcr	p15, 0, r0, c9, c2, 1
    149 
    150 	/* Flush Icache, Dcache, BTB */
    151 	mcr	p15, 0, r0, c7, c7, 0
    152 
    153 	/* Unlock I-TLB, D-TLB */
    154 	mcr	p15, 0, r0, c10, c4, 1
    155 	mcr	p15, 0, r0, c10, c8, 1
    156 
    157 	/* Flush TLB */
    158 	mcr	p15, 0, r0, c8, c7, 0
    159 
    160 	/* Allocate 4096 bytes of Dcache as RAM */
    161 
    162 	/* Drain pending loads and stores */
    163 	mcr	p15, 0, r0, c7, c10, 4
    164 
    165 	mov	r4, #0x00
    166 	mov	r5, #0x00
    167 	mov	r2, #0x01
    168 	mcr	p15, 0, r0, c9, c2, 0
    169 	CPWAIT	r0
    170 
    171 	/* 128 lines reserved (128 x 32bytes = 4096 bytes total) */
    172 	mov	r0, #128
    173 	ldr	r1, =0xfffff000
    174 
    175 alloc:
    176 	mcr	p15, 0, r1, c7, c2, 5
    177 	/* Drain pending loads and stores */
    178 	mcr	p15, 0, r0, c7, c10, 4
    179 	strd	r4, [r1], #8
    180 	strd	r4, [r1], #8
    181 	strd	r4, [r1], #8
    182 	strd	r4, [r1], #8
    183 	subs	r0, #0x01
    184 	bne	alloc
    185 	/* Drain pending loads and stores */
    186 	mcr	p15, 0, r0, c7, c10, 4
    187 	mov	r2, #0x00
    188 	mcr	p15, 0, r2, c9, c2, 0
    189 	CPWAIT	r0
    190 
    191 	mov	pc, lr
    192 
    193 .section .mmutable, "a"
    194 mmutable:
    195 	.align	14
    196 	/* 0x00000000 - 0xffe00000 : 1:1, uncached mapping */
    197 	.set	__base, 0
    198 	.rept	0xfff
    199 	.word	(__base << 20) | 0xc12
    200 	.set	__base, __base + 1
    201 	.endr
    202 
    203 	/* 0xfff00000 : 1:1, cached mapping */
    204 	.word	(0xfff << 20) | 0x1c1e
    205 #endif	/* CONFIG_CPU_PXA25X */
    206