xref: /openbmc/u-boot/arch/arm/cpu/arm1176/start.S (revision 85231c08)
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#include <linux/linkage.h>
20
21#ifndef CONFIG_SYS_PHY_UBOOT_BASE
22#define CONFIG_SYS_PHY_UBOOT_BASE	CONFIG_SYS_UBOOT_BASE
23#endif
24
25/*
26 *************************************************************************
27 *
28 * Startup Code (reset vector)
29 *
30 * do important init only if we don't start from memory!
31 * setup Memory and board specific bits prior to relocation.
32 * relocate armboot to ram
33 * setup stack
34 *
35 *************************************************************************
36 */
37
38	.globl reset
39
40reset:
41	/* Allow the board to save important registers */
42	b	save_boot_params
43.globl	save_boot_params_ret
44save_boot_params_ret:
45
46	/*
47	 * set the cpu to SVC32 mode
48	 */
49	mrs	r0, cpsr
50	bic	r0, r0, #0x3f
51	orr	r0, r0, #0xd3
52	msr	cpsr, r0
53
54/*
55 *************************************************************************
56 *
57 * CPU_init_critical registers
58 *
59 * setup important registers
60 * setup memory timing
61 *
62 *************************************************************************
63 */
64	/*
65	 * we do sys-critical inits only at reboot,
66	 * not when booting from ram!
67	 */
68cpu_init_crit:
69	/*
70	 * When booting from NAND - it has definitely been a reset, so, no need
71	 * to flush caches and disable the MMU
72	 */
73#ifndef CONFIG_SPL_BUILD
74	/*
75	 * flush v4 I/D caches
76	 */
77	mov	r0, #0
78	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
79	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
80
81	/*
82	 * disable MMU stuff and caches
83	 */
84	mrc	p15, 0, r0, c1, c0, 0
85	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
86	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
87	orr	r0, r0, #0x00000002	@ set bit 1 (A) Align
88	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
89
90	/* Prepare to disable the MMU */
91	adr	r2, mmu_disable_phys
92	sub	r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - CONFIG_SYS_TEXT_BASE)
93	b	mmu_disable
94
95	.align 5
96	/* Run in a single cache-line */
97mmu_disable:
98	mcr	p15, 0, r0, c1, c0, 0
99	nop
100	nop
101	mov	pc, r2
102mmu_disable_phys:
103
104#endif
105
106	/*
107	 * Go setup Memory and board specific bits prior to relocation.
108	 */
109	bl	lowlevel_init		/* go setup pll,mux,memory */
110
111	bl	_main
112
113/*------------------------------------------------------------------------------*/
114
115	.globl	c_runtime_cpu_setup
116c_runtime_cpu_setup:
117
118	mov	pc, lr
119
120WEAK(save_boot_params)
121	b	save_boot_params_ret	/* back to my caller */
122ENDPROC(save_boot_params)
123