xref: /openbmc/u-boot/arch/arm/cpu/sa1100/start.S (revision dd1033e4)
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 *  armboot - Startup Code for SA1100 CPU
4 *
5 *  Copyright (C) 1998	Dan Malek <dmalek@jlc.net>
6 *  Copyright (C) 1999	Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
7 *  Copyright (C) 2000	Wolfgang Denk <wd@denx.de>
8 *  Copyright (c) 2001	Alex Züpke <azu@sysgo.de>
9 */
10
11#include <asm-offsets.h>
12#include <config.h>
13
14/*
15 *************************************************************************
16 *
17 * Startup Code (reset vector)
18 *
19 * do important init only if we don't start from memory!
20 * relocate armboot to ram
21 * setup stack
22 * jump to second stage
23 *
24 *************************************************************************
25 */
26
27	.globl	reset
28
29reset:
30	/*
31	 * set the cpu to SVC32 mode
32	 */
33	mrs	r0,cpsr
34	bic	r0,r0,#0x1f
35	orr	r0,r0,#0xd3
36	msr	cpsr,r0
37
38	/*
39	 * we do sys-critical inits only at reboot,
40	 * not when booting from ram!
41	 */
42#ifndef CONFIG_SKIP_LOWLEVEL_INIT
43	bl	cpu_init_crit
44#endif
45
46	bl	_main
47
48/*------------------------------------------------------------------------------*/
49
50	.globl	c_runtime_cpu_setup
51c_runtime_cpu_setup:
52
53	mov	pc, lr
54
55/*
56 *************************************************************************
57 *
58 * CPU_init_critical registers
59 *
60 * setup important registers
61 * setup memory timing
62 *
63 *************************************************************************
64 */
65
66
67/* Interrupt-Controller base address */
68IC_BASE:	.word	0x90050000
69#define ICMR	0x04
70
71
72/* Reset-Controller */
73RST_BASE:		.word   0x90030000
74#define RSRR	0x00
75#define RCSR	0x04
76
77
78/* PWR */
79PWR_BASE:		.word   0x90020000
80#define PSPR    0x08
81#define PPCR    0x14
82cpuspeed:		.word   CONFIG_SYS_CPUSPEED
83
84
85cpu_init_crit:
86	/*
87	 * mask all IRQs
88	 */
89	ldr	r0, IC_BASE
90	mov	r1, #0x00
91	str	r1, [r0, #ICMR]
92
93	/* set clock speed */
94	ldr	r0, PWR_BASE
95	ldr	r1, cpuspeed
96	str	r1, [r0, #PPCR]
97
98#ifndef CONFIG_SKIP_LOWLEVEL_INIT_ONLY
99	/*
100	 * before relocating, we have to setup RAM timing
101	 * because memory timing is board-dependend, you will
102	 * find a lowlevel_init.S in your board directory.
103	 */
104	mov	ip,	lr
105	bl	lowlevel_init
106	mov	lr,	ip
107#endif
108
109	/*
110	 * disable MMU stuff and enable I-cache
111	 */
112	mrc	p15,0,r0,c1,c0
113	bic	r0, r0, #0x00002000	@ clear bit 13 (X)
114	bic	r0, r0, #0x0000000f	@ clear bits 3-0 (WCAM)
115	orr	r0, r0, #0x00001000	@ set bit 12 (I) Icache
116	orr	r0, r0, #0x00000002	@ set bit 1 (A) Align
117	mcr	p15,0,r0,c1,c0
118
119	/*
120	 * flush v4 I/D caches
121	 */
122	mov	r0, #0
123	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
124	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
125
126	mov	pc, lr
127