xref: /openbmc/u-boot/arch/arm/cpu/arm1176/start.S (revision e91610da)
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 *  armboot - Startup Code for ARM1176 CPU-core
4 *
5 * Copyright (c) 2007	Samsung Electronics
6 *
7 * Copyright (C) 2008
8 * Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de>
9 *
10 * 2007-09-21 - Restructured codes by jsgood (jsgood.yang@samsung.com)
11 * 2007-09-21 - Added MoviNAND and OneNAND boot codes by
12 * jsgood (jsgood.yang@samsung.com)
13 * Base codes by scsuh (sc.suh)
14 */
15
16#include <asm-offsets.h>
17#include <config.h>
18#include <linux/linkage.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	/* Allow the board to save important registers */
41	b	save_boot_params
42.globl	save_boot_params_ret
43save_boot_params_ret:
44
45	/*
46	 * set the cpu to SVC32 mode
47	 */
48	mrs	r0, cpsr
49	bic	r0, r0, #0x3f
50	orr	r0, r0, #0xd3
51	msr	cpsr, r0
52
53/*
54 *************************************************************************
55 *
56 * CPU_init_critical registers
57 *
58 * setup important registers
59 * setup memory timing
60 *
61 *************************************************************************
62 */
63	/*
64	 * we do sys-critical inits only at reboot,
65	 * not when booting from ram!
66	 */
67cpu_init_crit:
68	/*
69	 * When booting from NAND - it has definitely been a reset, so, no need
70	 * to flush caches and disable the MMU
71	 */
72#ifndef CONFIG_SPL_BUILD
73	/*
74	 * flush v4 I/D caches
75	 */
76	mov	r0, #0
77	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
78	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
79
80	/*
81	 * disable MMU stuff and caches
82	 */
83	mrc	p15, 0, r0, c1, c0, 0
84	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
85	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
86	orr	r0, r0, #0x00000002	@ set bit 1 (A) Align
87	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
88
89	/* Prepare to disable the MMU */
90	adr	r2, mmu_disable_phys
91	sub	r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - CONFIG_SYS_TEXT_BASE)
92	b	mmu_disable
93
94	.align 5
95	/* Run in a single cache-line */
96mmu_disable:
97	mcr	p15, 0, r0, c1, c0, 0
98	nop
99	nop
100	mov	pc, r2
101mmu_disable_phys:
102
103#endif
104
105	/*
106	 * Go setup Memory and board specific bits prior to relocation.
107	 */
108	bl	lowlevel_init		/* go setup pll,mux,memory */
109
110	bl	_main
111
112/*------------------------------------------------------------------------------*/
113
114	.globl	c_runtime_cpu_setup
115c_runtime_cpu_setup:
116
117	mov	pc, lr
118
119WEAK(save_boot_params)
120	b	save_boot_params_ret	/* back to my caller */
121ENDPROC(save_boot_params)
122