xref: /openbmc/u-boot/arch/arm/cpu/arm926ejs/spear/start.S (revision 12308b12)
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 *  armboot - Startup Code for ARM926EJS CPU-core
4 *
5 *  Copyright (c) 2003  Texas Instruments
6 *
7 *  ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
8 *
9 *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
10 *  Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
11 *  Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
12 *  Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
13 *  Copyright (c) 2003	Kshitij <kshitij@ti.com>
14 */
15
16
17#include <config.h>
18
19/*
20 *************************************************************************
21 *
22 * Startup Code (reset vector)
23 *
24 * Below are the critical initializations already taken place in BootROM.
25 * So, these are not taken care in Xloader
26 * 1. Relocation to RAM
27 * 2. Initializing stacks
28 *
29 *************************************************************************
30 */
31
32	.globl	reset
33
34reset:
35/*
36 * Xloader has to return back to BootROM in a few cases.
37 * eg. Ethernet boot, UART boot, USB boot
38 * Saving registers for returning back
39 */
40	stmdb	sp!, {r0-r12,r14}
41	bl	cpu_init_crit
42/*
43 * Clearing bss area is not done in Xloader.
44 * BSS area lies in the DDR location which is not yet initialized
45 * bss is assumed to be uninitialized.
46 */
47	ldmia	sp!, {r0-r12,pc}
48
49/*
50 *************************************************************************
51 *
52 * CPU_init_critical registers
53 *
54 * setup important registers
55 * setup memory timing
56 *
57 *************************************************************************
58 */
59cpu_init_crit:
60	/*
61	 * flush v4 I/D caches
62	 */
63	mov	r0, #0
64	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
65	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
66
67	/*
68	 * enable instruction cache
69	 */
70	mrc	p15, 0, r0, c1, c0, 0
71	orr	r0, r0, #0x00001000	/* set bit 12 (I) I-Cache */
72	mcr	p15, 0, r0, c1, c0, 0
73
74	/*
75	 * Go setup Memory and board specific bits prior to relocation.
76	 */
77	stmdb	sp!, {lr}
78	bl	_main	/* _main will call board_init_f */
79	ldmia	sp!, {pc}
80