xref: /openbmc/u-boot/arch/arm/cpu/arm1176/start.S (revision bdde6595)
1/*
2 *  armboot - Startup Code for ARM1176 CPU-core
3 *
4 * Copyright (c) 2007	Samsung Electronics
5 *
6 * Copyright (C) 2008
7 * Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de>
8 *
9 * SPDX-License-Identifier:	GPL-2.0+
10 *
11 * 2007-09-21 - Restructured codes by jsgood (jsgood.yang@samsung.com)
12 * 2007-09-21 - Added MoviNAND and OneNAND boot codes by
13 * jsgood (jsgood.yang@samsung.com)
14 * Base codes by scsuh (sc.suh)
15 */
16
17#include <asm-offsets.h>
18#include <config.h>
19
20#ifndef CONFIG_SYS_PHY_UBOOT_BASE
21#define CONFIG_SYS_PHY_UBOOT_BASE	CONFIG_SYS_UBOOT_BASE
22#endif
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
39reset:
40	/*
41	 * set the cpu to SVC32 mode
42	 */
43	mrs	r0, cpsr
44	bic	r0, r0, #0x3f
45	orr	r0, r0, #0xd3
46	msr	cpsr, r0
47
48/*
49 *************************************************************************
50 *
51 * CPU_init_critical registers
52 *
53 * setup important registers
54 * setup memory timing
55 *
56 *************************************************************************
57 */
58	/*
59	 * we do sys-critical inits only at reboot,
60	 * not when booting from ram!
61	 */
62cpu_init_crit:
63	/*
64	 * When booting from NAND - it has definitely been a reset, so, no need
65	 * to flush caches and disable the MMU
66	 */
67#ifndef CONFIG_SPL_BUILD
68	/*
69	 * flush v4 I/D caches
70	 */
71	mov	r0, #0
72	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
73	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
74
75	/*
76	 * disable MMU stuff and caches
77	 */
78	mrc	p15, 0, r0, c1, c0, 0
79	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
80	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
81	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
82	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
83
84	/* Prepare to disable the MMU */
85	adr	r2, mmu_disable_phys
86	sub	r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - CONFIG_SYS_TEXT_BASE)
87	b	mmu_disable
88
89	.align 5
90	/* Run in a single cache-line */
91mmu_disable:
92	mcr	p15, 0, r0, c1, c0, 0
93	nop
94	nop
95	mov	pc, r2
96mmu_disable_phys:
97
98#endif
99
100	/*
101	 * Go setup Memory and board specific bits prior to relocation.
102	 */
103	bl	lowlevel_init		/* go setup pll,mux,memory */
104
105	bl	_main
106
107/*------------------------------------------------------------------------------*/
108
109	.globl	c_runtime_cpu_setup
110c_runtime_cpu_setup:
111
112	mov	pc, lr
113