xref: /openbmc/u-boot/arch/arm/cpu/armv7/start.S (revision d648964f)
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	.globl	save_boot_params_ret
35
36reset:
37	/* Allow the board to save important registers */
38	b	save_boot_params
39save_boot_params_ret:
40	/*
41	 * disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
42	 * except if in HYP mode already
43	 */
44	mrs	r0, cpsr
45	and	r1, r0, #0x1f		@ mask mode bits
46	teq	r1, #0x1a		@ test for HYP mode
47	bicne	r0, r0, #0x1f		@ clear all mode bits
48	orrne	r0, r0, #0x13		@ set SVC mode
49	orr	r0, r0, #0xc0		@ disable FIQ and IRQ
50	msr	cpsr,r0
51
52/*
53 * Setup vector:
54 * (OMAP4 spl TEXT_BASE is not 32 byte aligned.
55 * Continue to use ROM code vector only in OMAP4 spl)
56 */
57#if !(defined(CONFIG_OMAP44XX) && defined(CONFIG_SPL_BUILD))
58	/* Set V=0 in CP15 SCTLR register - for VBAR to point to vector */
59	mrc	p15, 0, r0, c1, c0, 0	@ Read CP15 SCTLR Register
60	bic	r0, #CR_V		@ V = 0
61	mcr	p15, 0, r0, c1, c0, 0	@ Write CP15 SCTLR Register
62
63	/* Set vector address in CP15 VBAR register */
64	ldr	r0, =_start
65	mcr	p15, 0, r0, c12, c0, 0	@Set VBAR
66#endif
67
68	/* the mask ROM code should have PLL and others stable */
69#ifndef CONFIG_SKIP_LOWLEVEL_INIT
70	bl	cpu_init_cp15
71	bl	cpu_init_crit
72#endif
73
74	bl	_main
75
76/*------------------------------------------------------------------------------*/
77
78ENTRY(c_runtime_cpu_setup)
79/*
80 * If I-cache is enabled invalidate it
81 */
82#ifndef CONFIG_SYS_ICACHE_OFF
83	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
84	mcr     p15, 0, r0, c7, c10, 4	@ DSB
85	mcr     p15, 0, r0, c7, c5, 4	@ ISB
86#endif
87
88	bx	lr
89
90ENDPROC(c_runtime_cpu_setup)
91
92/*************************************************************************
93 *
94 * void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
95 *	__attribute__((weak));
96 *
97 * Stack pointer is not yet initialized at this moment
98 * Don't save anything to stack even if compiled with -O0
99 *
100 *************************************************************************/
101ENTRY(save_boot_params)
102	b	save_boot_params_ret		@ back to my caller
103ENDPROC(save_boot_params)
104	.weak	save_boot_params
105
106/*************************************************************************
107 *
108 * cpu_init_cp15
109 *
110 * Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless
111 * CONFIG_SYS_ICACHE_OFF is defined.
112 *
113 *************************************************************************/
114ENTRY(cpu_init_cp15)
115	/*
116	 * Invalidate L1 I/D
117	 */
118	mov	r0, #0			@ set up for MCR
119	mcr	p15, 0, r0, c8, c7, 0	@ invalidate TLBs
120	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
121	mcr	p15, 0, r0, c7, c5, 6	@ invalidate BP array
122	mcr     p15, 0, r0, c7, c10, 4	@ DSB
123	mcr     p15, 0, r0, c7, c5, 4	@ ISB
124
125	/*
126	 * disable MMU stuff and caches
127	 */
128	mrc	p15, 0, r0, c1, c0, 0
129	bic	r0, r0, #0x00002000	@ clear bits 13 (--V-)
130	bic	r0, r0, #0x00000007	@ clear bits 2:0 (-CAM)
131	orr	r0, r0, #0x00000002	@ set bit 1 (--A-) Align
132	orr	r0, r0, #0x00000800	@ set bit 11 (Z---) BTB
133#ifdef CONFIG_SYS_ICACHE_OFF
134	bic	r0, r0, #0x00001000	@ clear bit 12 (I) I-cache
135#else
136	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-cache
137#endif
138	mcr	p15, 0, r0, c1, c0, 0
139
140#ifdef CONFIG_ARM_ERRATA_716044
141	mrc	p15, 0, r0, c1, c0, 0	@ read system control register
142	orr	r0, r0, #1 << 11	@ set bit #11
143	mcr	p15, 0, r0, c1, c0, 0	@ write system control register
144#endif
145
146#if (defined(CONFIG_ARM_ERRATA_742230) || defined(CONFIG_ARM_ERRATA_794072))
147	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
148	orr	r0, r0, #1 << 4		@ set bit #4
149	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
150#endif
151
152#ifdef CONFIG_ARM_ERRATA_743622
153	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
154	orr	r0, r0, #1 << 6		@ set bit #6
155	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
156#endif
157
158#ifdef CONFIG_ARM_ERRATA_751472
159	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
160	orr	r0, r0, #1 << 11	@ set bit #11
161	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
162#endif
163#ifdef CONFIG_ARM_ERRATA_761320
164	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
165	orr	r0, r0, #1 << 21	@ set bit #21
166	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
167#endif
168
169	mov	pc, lr			@ back to my caller
170ENDPROC(cpu_init_cp15)
171
172#ifndef CONFIG_SKIP_LOWLEVEL_INIT
173/*************************************************************************
174 *
175 * CPU_init_critical registers
176 *
177 * setup important registers
178 * setup memory timing
179 *
180 *************************************************************************/
181ENTRY(cpu_init_crit)
182	/*
183	 * Jump to board specific initialization...
184	 * The Mask ROM will have already initialized
185	 * basic memory. Go here to bump up clock rate and handle
186	 * wake up conditions.
187	 */
188	b	lowlevel_init		@ go setup pll,mux,memory
189ENDPROC(cpu_init_crit)
190#endif
191