xref: /openbmc/u-boot/arch/arm/cpu/armv7/start.S (revision 2f20aa82)
1/*
2 * armboot - Startup Code for OMAP3530/ARM Cortex CPU-core
3 *
4 * Copyright (c) 2004	Texas Instruments <r-woodruff2@ti.com>
5 *
6 * Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
7 * Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
8 * Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
9 * Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
10 * Copyright (c) 2003	Kshitij <kshitij@ti.com>
11 * Copyright (c) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com>
12 *
13 * SPDX-License-Identifier:	GPL-2.0+
14 */
15
16#include <asm-offsets.h>
17#include <config.h>
18#include <version.h>
19#include <asm/system.h>
20#include <linux/linkage.h>
21
22/*************************************************************************
23 *
24 * Startup Code (reset vector)
25 *
26 * do important init only if we don't start from memory!
27 * setup Memory and board specific bits prior to relocation.
28 * relocate armboot to ram
29 * setup stack
30 *
31 *************************************************************************/
32
33	.globl	reset
34
35reset:
36	bl	save_boot_params
37	/*
38	 * disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
39	 * except if in HYP mode already
40	 */
41	mrs	r0, cpsr
42	and	r1, r0, #0x1f		@ mask mode bits
43	teq	r1, #0x1a		@ test for HYP mode
44	bicne	r0, r0, #0x1f		@ clear all mode bits
45	orrne	r0, r0, #0x13		@ set SVC mode
46	orr	r0, r0, #0xc0		@ disable FIQ and IRQ
47	msr	cpsr,r0
48
49/*
50 * Setup vector:
51 * (OMAP4 spl TEXT_BASE is not 32 byte aligned.
52 * Continue to use ROM code vector only in OMAP4 spl)
53 */
54#if !(defined(CONFIG_OMAP44XX) && defined(CONFIG_SPL_BUILD))
55	/* Set V=0 in CP15 SCTLR register - for VBAR to point to vector */
56	mrc	p15, 0, r0, c1, c0, 0	@ Read CP15 SCTLR Register
57	bic	r0, #CR_V		@ V = 0
58	mcr	p15, 0, r0, c1, c0, 0	@ Write CP15 SCTLR Register
59
60	/* Set vector address in CP15 VBAR register */
61	ldr	r0, =_start
62	mcr	p15, 0, r0, c12, c0, 0	@Set VBAR
63#endif
64
65	/* the mask ROM code should have PLL and others stable */
66#ifndef CONFIG_SKIP_LOWLEVEL_INIT
67	bl	cpu_init_cp15
68	bl	cpu_init_crit
69#endif
70
71	bl	_main
72
73/*------------------------------------------------------------------------------*/
74
75ENTRY(c_runtime_cpu_setup)
76/*
77 * If I-cache is enabled invalidate it
78 */
79#ifndef CONFIG_SYS_ICACHE_OFF
80	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
81	mcr     p15, 0, r0, c7, c10, 4	@ DSB
82	mcr     p15, 0, r0, c7, c5, 4	@ ISB
83#endif
84
85	bx	lr
86
87ENDPROC(c_runtime_cpu_setup)
88
89/*************************************************************************
90 *
91 * void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
92 *	__attribute__((weak));
93 *
94 * Stack pointer is not yet initialized at this moment
95 * Don't save anything to stack even if compiled with -O0
96 *
97 *************************************************************************/
98ENTRY(save_boot_params)
99	bx	lr			@ back to my caller
100ENDPROC(save_boot_params)
101	.weak	save_boot_params
102
103/*************************************************************************
104 *
105 * cpu_init_cp15
106 *
107 * Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless
108 * CONFIG_SYS_ICACHE_OFF is defined.
109 *
110 *************************************************************************/
111ENTRY(cpu_init_cp15)
112	/*
113	 * Invalidate L1 I/D
114	 */
115	mov	r0, #0			@ set up for MCR
116	mcr	p15, 0, r0, c8, c7, 0	@ invalidate TLBs
117	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
118	mcr	p15, 0, r0, c7, c5, 6	@ invalidate BP array
119	mcr     p15, 0, r0, c7, c10, 4	@ DSB
120	mcr     p15, 0, r0, c7, c5, 4	@ ISB
121
122	/*
123	 * disable MMU stuff and caches
124	 */
125	mrc	p15, 0, r0, c1, c0, 0
126	bic	r0, r0, #0x00002000	@ clear bits 13 (--V-)
127	bic	r0, r0, #0x00000007	@ clear bits 2:0 (-CAM)
128	orr	r0, r0, #0x00000002	@ set bit 1 (--A-) Align
129	orr	r0, r0, #0x00000800	@ set bit 11 (Z---) BTB
130#ifdef CONFIG_SYS_ICACHE_OFF
131	bic	r0, r0, #0x00001000	@ clear bit 12 (I) I-cache
132#else
133	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-cache
134#endif
135	mcr	p15, 0, r0, c1, c0, 0
136
137#ifdef CONFIG_ARM_ERRATA_716044
138	mrc	p15, 0, r0, c1, c0, 0	@ read system control register
139	orr	r0, r0, #1 << 11	@ set bit #11
140	mcr	p15, 0, r0, c1, c0, 0	@ write system control register
141#endif
142
143#if (defined(CONFIG_ARM_ERRATA_742230) || defined(CONFIG_ARM_ERRATA_794072))
144	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
145	orr	r0, r0, #1 << 4		@ set bit #4
146	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
147#endif
148
149#ifdef CONFIG_ARM_ERRATA_743622
150	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
151	orr	r0, r0, #1 << 6		@ set bit #6
152	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
153#endif
154
155#ifdef CONFIG_ARM_ERRATA_751472
156	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
157	orr	r0, r0, #1 << 11	@ set bit #11
158	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
159#endif
160#ifdef CONFIG_ARM_ERRATA_761320
161	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
162	orr	r0, r0, #1 << 21	@ set bit #21
163	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
164#endif
165
166	mov	pc, lr			@ back to my caller
167ENDPROC(cpu_init_cp15)
168
169#ifndef CONFIG_SKIP_LOWLEVEL_INIT
170/*************************************************************************
171 *
172 * CPU_init_critical registers
173 *
174 * setup important registers
175 * setup memory timing
176 *
177 *************************************************************************/
178ENTRY(cpu_init_crit)
179	/*
180	 * Jump to board specific initialization...
181	 * The Mask ROM will have already initialized
182	 * basic memory. Go here to bump up clock rate and handle
183	 * wake up conditions.
184	 */
185	b	lowlevel_init		@ go setup pll,mux,memory
186ENDPROC(cpu_init_crit)
187#endif
188