xref: /openbmc/u-boot/arch/arm/cpu/armv7/start.S (revision 274bced8)
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#include <asm/armv7.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. Setup stack.
29 *
30 *************************************************************************/
31
32	.globl	reset
33	.globl	save_boot_params_ret
34#ifdef CONFIG_ARMV7_LPAE
35	.global	switch_to_hypervisor_ret
36#endif
37
38reset:
39	/* Allow the board to save important registers */
40	b	save_boot_params
41save_boot_params_ret:
42#ifdef CONFIG_ARMV7_LPAE
43/*
44 * check for Hypervisor support
45 */
46	mrc	p15, 0, r0, c0, c1, 1		@ read ID_PFR1
47	and	r0, r0, #CPUID_ARM_VIRT_MASK	@ mask virtualization bits
48	cmp	r0, #(1 << CPUID_ARM_VIRT_SHIFT)
49	beq	switch_to_hypervisor
50switch_to_hypervisor_ret:
51#endif
52	/*
53	 * disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
54	 * except if in HYP mode already
55	 */
56	mrs	r0, cpsr
57	and	r1, r0, #0x1f		@ mask mode bits
58	teq	r1, #0x1a		@ test for HYP mode
59	bicne	r0, r0, #0x1f		@ clear all mode bits
60	orrne	r0, r0, #0x13		@ set SVC mode
61	orr	r0, r0, #0xc0		@ disable FIQ and IRQ
62	msr	cpsr,r0
63
64/*
65 * Setup vector:
66 * (OMAP4 spl TEXT_BASE is not 32 byte aligned.
67 * Continue to use ROM code vector only in OMAP4 spl)
68 */
69#if !(defined(CONFIG_OMAP44XX) && defined(CONFIG_SPL_BUILD))
70	/* Set V=0 in CP15 SCTLR register - for VBAR to point to vector */
71	mrc	p15, 0, r0, c1, c0, 0	@ Read CP15 SCTLR Register
72	bic	r0, #CR_V		@ V = 0
73	mcr	p15, 0, r0, c1, c0, 0	@ Write CP15 SCTLR Register
74
75	/* Set vector address in CP15 VBAR register */
76	ldr	r0, =_start
77	mcr	p15, 0, r0, c12, c0, 0	@Set VBAR
78#endif
79
80	/* the mask ROM code should have PLL and others stable */
81#ifndef CONFIG_SKIP_LOWLEVEL_INIT
82	bl	cpu_init_cp15
83#ifndef CONFIG_SKIP_LOWLEVEL_INIT_ONLY
84	bl	cpu_init_crit
85#endif
86#endif
87
88	bl	_main
89
90/*------------------------------------------------------------------------------*/
91
92ENTRY(c_runtime_cpu_setup)
93/*
94 * If I-cache is enabled invalidate it
95 */
96#ifndef CONFIG_SYS_ICACHE_OFF
97	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
98	mcr     p15, 0, r0, c7, c10, 4	@ DSB
99	mcr     p15, 0, r0, c7, c5, 4	@ ISB
100#endif
101
102	bx	lr
103
104ENDPROC(c_runtime_cpu_setup)
105
106/*************************************************************************
107 *
108 * void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
109 *	__attribute__((weak));
110 *
111 * Stack pointer is not yet initialized at this moment
112 * Don't save anything to stack even if compiled with -O0
113 *
114 *************************************************************************/
115ENTRY(save_boot_params)
116	b	save_boot_params_ret		@ back to my caller
117ENDPROC(save_boot_params)
118	.weak	save_boot_params
119
120#ifdef CONFIG_ARMV7_LPAE
121ENTRY(switch_to_hypervisor)
122	b	switch_to_hypervisor_ret
123ENDPROC(switch_to_hypervisor)
124	.weak	switch_to_hypervisor
125#endif
126
127/*************************************************************************
128 *
129 * cpu_init_cp15
130 *
131 * Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless
132 * CONFIG_SYS_ICACHE_OFF is defined.
133 *
134 *************************************************************************/
135ENTRY(cpu_init_cp15)
136	/*
137	 * Invalidate L1 I/D
138	 */
139	mov	r0, #0			@ set up for MCR
140	mcr	p15, 0, r0, c8, c7, 0	@ invalidate TLBs
141	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
142	mcr	p15, 0, r0, c7, c5, 6	@ invalidate BP array
143	mcr     p15, 0, r0, c7, c10, 4	@ DSB
144	mcr     p15, 0, r0, c7, c5, 4	@ ISB
145
146	/*
147	 * disable MMU stuff and caches
148	 */
149	mrc	p15, 0, r0, c1, c0, 0
150	bic	r0, r0, #0x00002000	@ clear bits 13 (--V-)
151	bic	r0, r0, #0x00000007	@ clear bits 2:0 (-CAM)
152	orr	r0, r0, #0x00000002	@ set bit 1 (--A-) Align
153	orr	r0, r0, #0x00000800	@ set bit 11 (Z---) BTB
154#ifdef CONFIG_SYS_ICACHE_OFF
155	bic	r0, r0, #0x00001000	@ clear bit 12 (I) I-cache
156#else
157	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-cache
158#endif
159	mcr	p15, 0, r0, c1, c0, 0
160
161#ifdef CONFIG_ARM_ERRATA_716044
162	mrc	p15, 0, r0, c1, c0, 0	@ read system control register
163	orr	r0, r0, #1 << 11	@ set bit #11
164	mcr	p15, 0, r0, c1, c0, 0	@ write system control register
165#endif
166
167#if (defined(CONFIG_ARM_ERRATA_742230) || defined(CONFIG_ARM_ERRATA_794072))
168	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
169	orr	r0, r0, #1 << 4		@ set bit #4
170	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
171#endif
172
173#ifdef CONFIG_ARM_ERRATA_743622
174	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
175	orr	r0, r0, #1 << 6		@ set bit #6
176	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
177#endif
178
179#ifdef CONFIG_ARM_ERRATA_751472
180	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
181	orr	r0, r0, #1 << 11	@ set bit #11
182	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
183#endif
184#ifdef CONFIG_ARM_ERRATA_761320
185	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
186	orr	r0, r0, #1 << 21	@ set bit #21
187	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
188#endif
189
190	mov	r5, lr			@ Store my Caller
191	mrc	p15, 0, r1, c0, c0, 0	@ r1 has Read Main ID Register (MIDR)
192	mov	r3, r1, lsr #20		@ get variant field
193	and	r3, r3, #0xf		@ r3 has CPU variant
194	and	r4, r1, #0xf		@ r4 has CPU revision
195	mov	r2, r3, lsl #4		@ shift variant field for combined value
196	orr	r2, r4, r2		@ r2 has combined CPU variant + revision
197
198#ifdef CONFIG_ARM_ERRATA_798870
199	cmp	r2, #0x30		@ Applies to lower than R3p0
200	bge	skip_errata_798870      @ skip if not affected rev
201	cmp	r2, #0x20		@ Applies to including and above R2p0
202	blt	skip_errata_798870      @ skip if not affected rev
203
204	mrc	p15, 1, r0, c15, c0, 0  @ read l2 aux ctrl reg
205	orr	r0, r0, #1 << 7         @ Enable hazard-detect timeout
206	push	{r1-r5}			@ Save the cpu info registers
207	bl	v7_arch_cp15_set_l2aux_ctrl
208	isb				@ Recommended ISB after l2actlr update
209	pop	{r1-r5}			@ Restore the cpu info - fall through
210skip_errata_798870:
211#endif
212
213#ifdef CONFIG_ARM_ERRATA_801819
214	cmp	r2, #0x24		@ Applies to lt including R2p4
215	bgt	skip_errata_801819      @ skip if not affected rev
216	cmp	r2, #0x20		@ Applies to including and above R2p0
217	blt	skip_errata_801819      @ skip if not affected rev
218	mrc	p15, 0, r0, c0, c0, 6	@ pick up REVIDR reg
219	and	r0, r0, #1 << 3		@ check REVIDR[3]
220	cmp	r0, #1 << 3
221	beq	skip_errata_801819	@ skip erratum if REVIDR[3] is set
222
223	mrc	p15, 0, r0, c1, c0, 1	@ read auxilary control register
224	orr	r0, r0, #3 << 27	@ Disables streaming. All write-allocate
225					@ lines allocate in the L1 or L2 cache.
226	orr	r0, r0, #3 << 25	@ Disables streaming. All write-allocate
227					@ lines allocate in the L1 cache.
228	push	{r1-r5}			@ Save the cpu info registers
229	bl	v7_arch_cp15_set_acr
230	pop	{r1-r5}			@ Restore the cpu info - fall through
231skip_errata_801819:
232#endif
233
234#ifdef CONFIG_ARM_ERRATA_454179
235	cmp	r2, #0x21		@ Only on < r2p1
236	bge	skip_errata_454179
237
238	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
239	orr	r0, r0, #(0x3 << 6)	@ Set DBSM(BIT7) and IBE(BIT6) bits
240	push	{r1-r5}			@ Save the cpu info registers
241	bl	v7_arch_cp15_set_acr
242	pop	{r1-r5}			@ Restore the cpu info - fall through
243
244skip_errata_454179:
245#endif
246
247#ifdef CONFIG_ARM_ERRATA_430973
248	cmp	r2, #0x21		@ Only on < r2p1
249	bge	skip_errata_430973
250
251	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
252	orr	r0, r0, #(0x1 << 6)	@ Set IBE bit
253	push	{r1-r5}			@ Save the cpu info registers
254	bl	v7_arch_cp15_set_acr
255	pop	{r1-r5}			@ Restore the cpu info - fall through
256
257skip_errata_430973:
258#endif
259
260#ifdef CONFIG_ARM_ERRATA_621766
261	cmp	r2, #0x21		@ Only on < r2p1
262	bge	skip_errata_621766
263
264	mrc	p15, 0, r0, c1, c0, 1	@ Read ACR
265	orr	r0, r0, #(0x1 << 5)	@ Set L1NEON bit
266	push	{r1-r5}			@ Save the cpu info registers
267	bl	v7_arch_cp15_set_acr
268	pop	{r1-r5}			@ Restore the cpu info - fall through
269
270skip_errata_621766:
271#endif
272
273#ifdef CONFIG_ARM_ERRATA_725233
274	cmp	r2, #0x21		@ Only on < r2p1 (Cortex A8)
275	bge	skip_errata_725233
276
277	mrc	p15, 1, r0, c9, c0, 2	@ Read L2ACR
278	orr	r0, r0, #(0x1 << 27)	@ L2 PLD data forwarding disable
279	push	{r1-r5}			@ Save the cpu info registers
280	bl	v7_arch_cp15_set_l2aux_ctrl
281	pop	{r1-r5}			@ Restore the cpu info - fall through
282
283skip_errata_725233:
284#endif
285
286	mov	pc, r5			@ back to my caller
287ENDPROC(cpu_init_cp15)
288
289#if !defined(CONFIG_SKIP_LOWLEVEL_INIT) && \
290	!defined(CONFIG_SKIP_LOWLEVEL_INIT_ONLY)
291/*************************************************************************
292 *
293 * CPU_init_critical registers
294 *
295 * setup important registers
296 * setup memory timing
297 *
298 *************************************************************************/
299ENTRY(cpu_init_crit)
300	/*
301	 * Jump to board specific initialization...
302	 * The Mask ROM will have already initialized
303	 * basic memory. Go here to bump up clock rate and handle
304	 * wake up conditions.
305	 */
306	b	lowlevel_init		@ go setup pll,mux,memory
307ENDPROC(cpu_init_crit)
308#endif
309