xref: /openbmc/u-boot/arch/arm/cpu/armv7/start.S (revision bdde6595)
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 <asm/system.h>
19#include <linux/linkage.h>
20
21/*************************************************************************
22 *
23 * Startup Code (reset vector)
24 *
25 * do important init only if we don't start from memory!
26 * setup Memory and board specific bits prior to relocation.
27 * relocate armboot to ram
28 * setup stack
29 *
30 *************************************************************************/
31
32	.globl	reset
33	.globl	save_boot_params_ret
34
35reset:
36	/* Allow the board to save important registers */
37	b	save_boot_params
38save_boot_params_ret:
39	/*
40	 * disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
41	 * except if in HYP mode already
42	 */
43	mrs	r0, cpsr
44	and	r1, r0, #0x1f		@ mask mode bits
45	teq	r1, #0x1a		@ test for HYP mode
46	bicne	r0, r0, #0x1f		@ clear all mode bits
47	orrne	r0, r0, #0x13		@ set SVC mode
48	orr	r0, r0, #0xc0		@ disable FIQ and IRQ
49	msr	cpsr,r0
50
51/*
52 * Setup vector:
53 * (OMAP4 spl TEXT_BASE is not 32 byte aligned.
54 * Continue to use ROM code vector only in OMAP4 spl)
55 */
56#if !(defined(CONFIG_OMAP44XX) && defined(CONFIG_SPL_BUILD))
57	/* Set V=0 in CP15 SCTLR register - for VBAR to point to vector */
58	mrc	p15, 0, r0, c1, c0, 0	@ Read CP15 SCTLR Register
59	bic	r0, #CR_V		@ V = 0
60	mcr	p15, 0, r0, c1, c0, 0	@ Write CP15 SCTLR Register
61
62	/* Set vector address in CP15 VBAR register */
63	ldr	r0, =_start
64	mcr	p15, 0, r0, c12, c0, 0	@Set VBAR
65#endif
66
67	/* the mask ROM code should have PLL and others stable */
68#ifndef CONFIG_SKIP_LOWLEVEL_INIT
69	bl	cpu_init_cp15
70	bl	cpu_init_crit
71#endif
72
73	bl	_main
74
75/*------------------------------------------------------------------------------*/
76
77ENTRY(c_runtime_cpu_setup)
78/*
79 * If I-cache is enabled invalidate it
80 */
81#ifndef CONFIG_SYS_ICACHE_OFF
82	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
83	mcr     p15, 0, r0, c7, c10, 4	@ DSB
84	mcr     p15, 0, r0, c7, c5, 4	@ ISB
85#endif
86
87	bx	lr
88
89ENDPROC(c_runtime_cpu_setup)
90
91/*************************************************************************
92 *
93 * void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
94 *	__attribute__((weak));
95 *
96 * Stack pointer is not yet initialized at this moment
97 * Don't save anything to stack even if compiled with -O0
98 *
99 *************************************************************************/
100ENTRY(save_boot_params)
101	b	save_boot_params_ret		@ back to my caller
102ENDPROC(save_boot_params)
103	.weak	save_boot_params
104
105/*************************************************************************
106 *
107 * cpu_init_cp15
108 *
109 * Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless
110 * CONFIG_SYS_ICACHE_OFF is defined.
111 *
112 *************************************************************************/
113ENTRY(cpu_init_cp15)
114	/*
115	 * Invalidate L1 I/D
116	 */
117	mov	r0, #0			@ set up for MCR
118	mcr	p15, 0, r0, c8, c7, 0	@ invalidate TLBs
119	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
120	mcr	p15, 0, r0, c7, c5, 6	@ invalidate BP array
121	mcr     p15, 0, r0, c7, c10, 4	@ DSB
122	mcr     p15, 0, r0, c7, c5, 4	@ ISB
123
124	/*
125	 * disable MMU stuff and caches
126	 */
127	mrc	p15, 0, r0, c1, c0, 0
128	bic	r0, r0, #0x00002000	@ clear bits 13 (--V-)
129	bic	r0, r0, #0x00000007	@ clear bits 2:0 (-CAM)
130	orr	r0, r0, #0x00000002	@ set bit 1 (--A-) Align
131	orr	r0, r0, #0x00000800	@ set bit 11 (Z---) BTB
132#ifdef CONFIG_SYS_ICACHE_OFF
133	bic	r0, r0, #0x00001000	@ clear bit 12 (I) I-cache
134#else
135	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-cache
136#endif
137	mcr	p15, 0, r0, c1, c0, 0
138
139#ifdef CONFIG_ARM_ERRATA_716044
140	mrc	p15, 0, r0, c1, c0, 0	@ read system control register
141	orr	r0, r0, #1 << 11	@ set bit #11
142	mcr	p15, 0, r0, c1, c0, 0	@ write system control register
143#endif
144
145#if (defined(CONFIG_ARM_ERRATA_742230) || defined(CONFIG_ARM_ERRATA_794072))
146	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
147	orr	r0, r0, #1 << 4		@ set bit #4
148	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
149#endif
150
151#ifdef CONFIG_ARM_ERRATA_743622
152	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
153	orr	r0, r0, #1 << 6		@ set bit #6
154	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
155#endif
156
157#ifdef CONFIG_ARM_ERRATA_751472
158	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
159	orr	r0, r0, #1 << 11	@ set bit #11
160	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
161#endif
162#ifdef CONFIG_ARM_ERRATA_761320
163	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
164	orr	r0, r0, #1 << 21	@ set bit #21
165	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
166#endif
167
168	mov	r5, lr			@ Store my Caller
169	mrc	p15, 0, r1, c0, c0, 0	@ r1 has Read Main ID Register (MIDR)
170	mov	r3, r1, lsr #20		@ get variant field
171	and	r3, r3, #0xf		@ r3 has CPU variant
172	and	r4, r1, #0xf		@ r4 has CPU revision
173	mov	r2, r3, lsl #4		@ shift variant field for combined value
174	orr	r2, r4, r2		@ r2 has combined CPU variant + revision
175
176#ifdef CONFIG_ARM_ERRATA_798870
177	cmp	r2, #0x30		@ Applies to lower than R3p0
178	bge	skip_errata_798870      @ skip if not affected rev
179	cmp	r2, #0x20		@ Applies to including and above R2p0
180	blt	skip_errata_798870      @ skip if not affected rev
181
182	mrc	p15, 1, r0, c15, c0, 0  @ read l2 aux ctrl reg
183	orr	r0, r0, #1 << 7         @ Enable hazard-detect timeout
184	push	{r1-r5}			@ Save the cpu info registers
185	bl	v7_arch_cp15_set_l2aux_ctrl
186	isb				@ Recommended ISB after l2actlr update
187	pop	{r1-r5}			@ Restore the cpu info - fall through
188skip_errata_798870:
189#endif
190
191#ifdef CONFIG_ARM_ERRATA_454179
192	cmp	r2, #0x21		@ Only on < r2p1
193	bge	skip_errata_454179
194
195	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
196	orr	r0, r0, #(0x3 << 6)	@ Set DBSM(BIT7) and IBE(BIT6) bits
197	push	{r1-r5}			@ Save the cpu info registers
198	bl	v7_arch_cp15_set_acr
199	pop	{r1-r5}			@ Restore the cpu info - fall through
200
201skip_errata_454179:
202#endif
203
204#ifdef CONFIG_ARM_ERRATA_430973
205	cmp	r2, #0x21		@ Only on < r2p1
206	bge	skip_errata_430973
207
208	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
209	orr	r0, r0, #(0x1 << 6)	@ Set IBE bit
210	push	{r1-r5}			@ Save the cpu info registers
211	bl	v7_arch_cp15_set_acr
212	pop	{r1-r5}			@ Restore the cpu info - fall through
213
214skip_errata_430973:
215#endif
216
217#ifdef CONFIG_ARM_ERRATA_621766
218	cmp	r2, #0x21		@ Only on < r2p1
219	bge	skip_errata_621766
220
221	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
222	orr	r0, r0, #(0x1 << 5)	@ Set L1NEON bit
223	push	{r1-r5}			@ Save the cpu info registers
224	bl	v7_arch_cp15_set_acr
225	pop	{r1-r5}			@ Restore the cpu info - fall through
226
227skip_errata_621766:
228#endif
229
230	mov	pc, r5			@ back to my caller
231ENDPROC(cpu_init_cp15)
232
233#ifndef CONFIG_SKIP_LOWLEVEL_INIT
234/*************************************************************************
235 *
236 * CPU_init_critical registers
237 *
238 * setup important registers
239 * setup memory timing
240 *
241 *************************************************************************/
242ENTRY(cpu_init_crit)
243	/*
244	 * Jump to board specific initialization...
245	 * The Mask ROM will have already initialized
246	 * basic memory. Go here to bump up clock rate and handle
247	 * wake up conditions.
248	 */
249	b	lowlevel_init		@ go setup pll,mux,memory
250ENDPROC(cpu_init_crit)
251#endif
252