xref: /openbmc/u-boot/arch/arm/cpu/arm720t/start.S (revision ed09a554)
1/*
2 *  armboot - Startup Code for ARM720 CPU-core
3 *
4 *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
5 *  Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
6 *
7 * SPDX-License-Identifier:	GPL-2.0+
8 */
9
10#include <asm-offsets.h>
11#include <config.h>
12#include <asm/hardware.h>
13
14/*
15 *************************************************************************
16 *
17 * Startup Code (reset vector)
18 *
19 * do important init only if we don't start from RAM!
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#ifndef CONFIG_SKIP_LOWLEVEL_INIT
67cpu_init_crit:
68
69	mov	ip, lr
70	/*
71	 * before relocating, we have to setup RAM timing
72	 * because memory timing is board-dependent, you will
73	 * find a lowlevel_init.S in your board directory.
74	 */
75	bl	lowlevel_init
76	mov	lr, ip
77
78	mov	pc, lr
79#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
80