xref: /openbmc/u-boot/arch/arm/cpu/armv7/start.S (revision fea7f3aa)
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. Setup stack.
28 *
29 *************************************************************************/
30
31	.globl	reset
32	.globl	save_boot_params_ret
33
34reset:
35	/* Allow the board to save important registers */
36	b	save_boot_params
37save_boot_params_ret:
38	/*
39	 * disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
40	 * except if in HYP mode already
41	 */
42	mrs	r0, cpsr
43	and	r1, r0, #0x1f		@ mask mode bits
44	teq	r1, #0x1a		@ test for HYP mode
45	bicne	r0, r0, #0x1f		@ clear all mode bits
46	orrne	r0, r0, #0x13		@ set SVC mode
47	orr	r0, r0, #0xc0		@ disable FIQ and IRQ
48	msr	cpsr,r0
49
50/*
51 * Setup vector:
52 * (OMAP4 spl TEXT_BASE is not 32 byte aligned.
53 * Continue to use ROM code vector only in OMAP4 spl)
54 */
55#if !(defined(CONFIG_OMAP44XX) && defined(CONFIG_SPL_BUILD))
56	/* Set V=0 in CP15 SCTLR register - for VBAR to point to vector */
57	mrc	p15, 0, r0, c1, c0, 0	@ Read CP15 SCTLR Register
58	bic	r0, #CR_V		@ V = 0
59	mcr	p15, 0, r0, c1, c0, 0	@ Write CP15 SCTLR Register
60
61	/* Set vector address in CP15 VBAR register */
62	ldr	r0, =_start
63	mcr	p15, 0, r0, c12, c0, 0	@Set VBAR
64#endif
65
66	/* the mask ROM code should have PLL and others stable */
67#ifndef CONFIG_SKIP_LOWLEVEL_INIT
68	bl	cpu_init_cp15
69	bl	cpu_init_crit
70#endif
71
72	bl	_main
73
74/*------------------------------------------------------------------------------*/
75
76ENTRY(c_runtime_cpu_setup)
77/*
78 * If I-cache is enabled invalidate it
79 */
80#ifndef CONFIG_SYS_ICACHE_OFF
81	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
82	mcr     p15, 0, r0, c7, c10, 4	@ DSB
83	mcr     p15, 0, r0, c7, c5, 4	@ ISB
84#endif
85
86	bx	lr
87
88ENDPROC(c_runtime_cpu_setup)
89
90/*************************************************************************
91 *
92 * void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
93 *	__attribute__((weak));
94 *
95 * Stack pointer is not yet initialized at this moment
96 * Don't save anything to stack even if compiled with -O0
97 *
98 *************************************************************************/
99ENTRY(save_boot_params)
100	b	save_boot_params_ret		@ back to my caller
101ENDPROC(save_boot_params)
102	.weak	save_boot_params
103
104/*************************************************************************
105 *
106 * cpu_init_cp15
107 *
108 * Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless
109 * CONFIG_SYS_ICACHE_OFF is defined.
110 *
111 *************************************************************************/
112ENTRY(cpu_init_cp15)
113	/*
114	 * Invalidate L1 I/D
115	 */
116	mov	r0, #0			@ set up for MCR
117	mcr	p15, 0, r0, c8, c7, 0	@ invalidate TLBs
118	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
119	mcr	p15, 0, r0, c7, c5, 6	@ invalidate BP array
120	mcr     p15, 0, r0, c7, c10, 4	@ DSB
121	mcr     p15, 0, r0, c7, c5, 4	@ ISB
122
123	/*
124	 * disable MMU stuff and caches
125	 */
126	mrc	p15, 0, r0, c1, c0, 0
127	bic	r0, r0, #0x00002000	@ clear bits 13 (--V-)
128	bic	r0, r0, #0x00000007	@ clear bits 2:0 (-CAM)
129	orr	r0, r0, #0x00000002	@ set bit 1 (--A-) Align
130	orr	r0, r0, #0x00000800	@ set bit 11 (Z---) BTB
131#ifdef CONFIG_SYS_ICACHE_OFF
132	bic	r0, r0, #0x00001000	@ clear bit 12 (I) I-cache
133#else
134	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-cache
135#endif
136	mcr	p15, 0, r0, c1, c0, 0
137
138#ifdef CONFIG_ARM_ERRATA_716044
139	mrc	p15, 0, r0, c1, c0, 0	@ read system control register
140	orr	r0, r0, #1 << 11	@ set bit #11
141	mcr	p15, 0, r0, c1, c0, 0	@ write system control register
142#endif
143
144#if (defined(CONFIG_ARM_ERRATA_742230) || defined(CONFIG_ARM_ERRATA_794072))
145	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
146	orr	r0, r0, #1 << 4		@ set bit #4
147	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
148#endif
149
150#ifdef CONFIG_ARM_ERRATA_743622
151	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
152	orr	r0, r0, #1 << 6		@ set bit #6
153	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
154#endif
155
156#ifdef CONFIG_ARM_ERRATA_751472
157	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
158	orr	r0, r0, #1 << 11	@ set bit #11
159	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
160#endif
161#ifdef CONFIG_ARM_ERRATA_761320
162	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
163	orr	r0, r0, #1 << 21	@ set bit #21
164	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
165#endif
166
167	mov	r5, lr			@ Store my Caller
168	mrc	p15, 0, r1, c0, c0, 0	@ r1 has Read Main ID Register (MIDR)
169	mov	r3, r1, lsr #20		@ get variant field
170	and	r3, r3, #0xf		@ r3 has CPU variant
171	and	r4, r1, #0xf		@ r4 has CPU revision
172	mov	r2, r3, lsl #4		@ shift variant field for combined value
173	orr	r2, r4, r2		@ r2 has combined CPU variant + revision
174
175#ifdef CONFIG_ARM_ERRATA_798870
176	cmp	r2, #0x30		@ Applies to lower than R3p0
177	bge	skip_errata_798870      @ skip if not affected rev
178	cmp	r2, #0x20		@ Applies to including and above R2p0
179	blt	skip_errata_798870      @ skip if not affected rev
180
181	mrc	p15, 1, r0, c15, c0, 0  @ read l2 aux ctrl reg
182	orr	r0, r0, #1 << 7         @ Enable hazard-detect timeout
183	push	{r1-r5}			@ Save the cpu info registers
184	bl	v7_arch_cp15_set_l2aux_ctrl
185	isb				@ Recommended ISB after l2actlr update
186	pop	{r1-r5}			@ Restore the cpu info - fall through
187skip_errata_798870:
188#endif
189
190#ifdef CONFIG_ARM_ERRATA_801819
191	cmp	r2, #0x24		@ Applies to lt including R2p4
192	bgt	skip_errata_801819      @ skip if not affected rev
193	cmp	r2, #0x20		@ Applies to including and above R2p0
194	blt	skip_errata_801819      @ skip if not affected rev
195	mrc	p15, 0, r0, c0, c0, 6	@ pick up REVIDR reg
196	and	r0, r0, #1 << 3		@ check REVIDR[3]
197	cmp	r0, #1 << 3
198	beq	skip_errata_801819	@ skip erratum if REVIDR[3] is set
199
200	mrc	p15, 0, r0, c1, c0, 1	@ read auxilary control register
201	orr	r0, r0, #3 << 27	@ Disables streaming. All write-allocate
202					@ lines allocate in the L1 or L2 cache.
203	orr	r0, r0, #3 << 25	@ Disables streaming. All write-allocate
204					@ lines allocate in the L1 cache.
205	push	{r1-r5}			@ Save the cpu info registers
206	bl	v7_arch_cp15_set_acr
207	pop	{r1-r5}			@ Restore the cpu info - fall through
208skip_errata_801819:
209#endif
210
211#ifdef CONFIG_ARM_ERRATA_454179
212	cmp	r2, #0x21		@ Only on < r2p1
213	bge	skip_errata_454179
214
215	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
216	orr	r0, r0, #(0x3 << 6)	@ Set DBSM(BIT7) and IBE(BIT6) bits
217	push	{r1-r5}			@ Save the cpu info registers
218	bl	v7_arch_cp15_set_acr
219	pop	{r1-r5}			@ Restore the cpu info - fall through
220
221skip_errata_454179:
222#endif
223
224#ifdef CONFIG_ARM_ERRATA_430973
225	cmp	r2, #0x21		@ Only on < r2p1
226	bge	skip_errata_430973
227
228	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
229	orr	r0, r0, #(0x1 << 6)	@ Set IBE bit
230	push	{r1-r5}			@ Save the cpu info registers
231	bl	v7_arch_cp15_set_acr
232	pop	{r1-r5}			@ Restore the cpu info - fall through
233
234skip_errata_430973:
235#endif
236
237#ifdef CONFIG_ARM_ERRATA_621766
238	cmp	r2, #0x21		@ Only on < r2p1
239	bge	skip_errata_621766
240
241	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
242	orr	r0, r0, #(0x1 << 5)	@ Set L1NEON bit
243	push	{r1-r5}			@ Save the cpu info registers
244	bl	v7_arch_cp15_set_acr
245	pop	{r1-r5}			@ Restore the cpu info - fall through
246
247skip_errata_621766:
248#endif
249
250	mov	pc, r5			@ back to my caller
251ENDPROC(cpu_init_cp15)
252
253#ifndef CONFIG_SKIP_LOWLEVEL_INIT
254/*************************************************************************
255 *
256 * CPU_init_critical registers
257 *
258 * setup important registers
259 * setup memory timing
260 *
261 *************************************************************************/
262ENTRY(cpu_init_crit)
263	/*
264	 * Jump to board specific initialization...
265	 * The Mask ROM will have already initialized
266	 * basic memory. Go here to bump up clock rate and handle
267	 * wake up conditions.
268	 */
269	b	lowlevel_init		@ go setup pll,mux,memory
270ENDPROC(cpu_init_crit)
271#endif
272