xref: /openbmc/u-boot/arch/arm/cpu/armv7/start.S (revision 473af36a)
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#ifndef CONFIG_SKIP_LOWLEVEL_INIT_ONLY
70	bl	cpu_init_crit
71#endif
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	r5, lr			@ Store my Caller
170	mrc	p15, 0, r1, c0, c0, 0	@ r1 has Read Main ID Register (MIDR)
171	mov	r3, r1, lsr #20		@ get variant field
172	and	r3, r3, #0xf		@ r3 has CPU variant
173	and	r4, r1, #0xf		@ r4 has CPU revision
174	mov	r2, r3, lsl #4		@ shift variant field for combined value
175	orr	r2, r4, r2		@ r2 has combined CPU variant + revision
176
177#ifdef CONFIG_ARM_ERRATA_798870
178	cmp	r2, #0x30		@ Applies to lower than R3p0
179	bge	skip_errata_798870      @ skip if not affected rev
180	cmp	r2, #0x20		@ Applies to including and above R2p0
181	blt	skip_errata_798870      @ skip if not affected rev
182
183	mrc	p15, 1, r0, c15, c0, 0  @ read l2 aux ctrl reg
184	orr	r0, r0, #1 << 7         @ Enable hazard-detect timeout
185	push	{r1-r5}			@ Save the cpu info registers
186	bl	v7_arch_cp15_set_l2aux_ctrl
187	isb				@ Recommended ISB after l2actlr update
188	pop	{r1-r5}			@ Restore the cpu info - fall through
189skip_errata_798870:
190#endif
191
192#ifdef CONFIG_ARM_ERRATA_801819
193	cmp	r2, #0x24		@ Applies to lt including R2p4
194	bgt	skip_errata_801819      @ skip if not affected rev
195	cmp	r2, #0x20		@ Applies to including and above R2p0
196	blt	skip_errata_801819      @ skip if not affected rev
197	mrc	p15, 0, r0, c0, c0, 6	@ pick up REVIDR reg
198	and	r0, r0, #1 << 3		@ check REVIDR[3]
199	cmp	r0, #1 << 3
200	beq	skip_errata_801819	@ skip erratum if REVIDR[3] is set
201
202	mrc	p15, 0, r0, c1, c0, 1	@ read auxilary control register
203	orr	r0, r0, #3 << 27	@ Disables streaming. All write-allocate
204					@ lines allocate in the L1 or L2 cache.
205	orr	r0, r0, #3 << 25	@ Disables streaming. All write-allocate
206					@ lines allocate in the L1 cache.
207	push	{r1-r5}			@ Save the cpu info registers
208	bl	v7_arch_cp15_set_acr
209	pop	{r1-r5}			@ Restore the cpu info - fall through
210skip_errata_801819:
211#endif
212
213#ifdef CONFIG_ARM_ERRATA_454179
214	cmp	r2, #0x21		@ Only on < r2p1
215	bge	skip_errata_454179
216
217	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
218	orr	r0, r0, #(0x3 << 6)	@ Set DBSM(BIT7) and IBE(BIT6) bits
219	push	{r1-r5}			@ Save the cpu info registers
220	bl	v7_arch_cp15_set_acr
221	pop	{r1-r5}			@ Restore the cpu info - fall through
222
223skip_errata_454179:
224#endif
225
226#ifdef CONFIG_ARM_ERRATA_430973
227	cmp	r2, #0x21		@ Only on < r2p1
228	bge	skip_errata_430973
229
230	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
231	orr	r0, r0, #(0x1 << 6)	@ Set IBE bit
232	push	{r1-r5}			@ Save the cpu info registers
233	bl	v7_arch_cp15_set_acr
234	pop	{r1-r5}			@ Restore the cpu info - fall through
235
236skip_errata_430973:
237#endif
238
239#ifdef CONFIG_ARM_ERRATA_621766
240	cmp	r2, #0x21		@ Only on < r2p1
241	bge	skip_errata_621766
242
243	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
244	orr	r0, r0, #(0x1 << 5)	@ Set L1NEON bit
245	push	{r1-r5}			@ Save the cpu info registers
246	bl	v7_arch_cp15_set_acr
247	pop	{r1-r5}			@ Restore the cpu info - fall through
248
249skip_errata_621766:
250#endif
251
252	mov	pc, r5			@ back to my caller
253ENDPROC(cpu_init_cp15)
254
255#if !defined(CONFIG_SKIP_LOWLEVEL_INIT) && \
256	!defined(CONFIG_SKIP_LOWLEVEL_INIT_ONLY)
257/*************************************************************************
258 *
259 * CPU_init_critical registers
260 *
261 * setup important registers
262 * setup memory timing
263 *
264 *************************************************************************/
265ENTRY(cpu_init_crit)
266	/*
267	 * Jump to board specific initialization...
268	 * The Mask ROM will have already initialized
269	 * basic memory. Go here to bump up clock rate and handle
270	 * wake up conditions.
271	 */
272	b	lowlevel_init		@ go setup pll,mux,memory
273ENDPROC(cpu_init_crit)
274#endif
275