xref: /openbmc/u-boot/arch/arm/cpu/armv8/start.S (revision 85231c08)
1/*
2 * (C) Copyright 2013
3 * David Feng <fenghua@phytium.com.cn>
4 *
5 * SPDX-License-Identifier:	GPL-2.0+
6 */
7
8#include <asm-offsets.h>
9#include <config.h>
10#include <linux/linkage.h>
11#include <asm/macro.h>
12#include <asm/armv8/mmu.h>
13
14/*************************************************************************
15 *
16 * Startup Code (reset vector)
17 *
18 *************************************************************************/
19
20.globl	_start
21_start:
22#if defined(LINUX_KERNEL_IMAGE_HEADER)
23#include <asm/boot0-linux-kernel-header.h>
24#elif defined(CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK)
25/*
26 * Various SoCs need something special and SoC-specific up front in
27 * order to boot, allow them to set that in their boot0.h file and then
28 * use it here.
29 */
30#include <asm/arch/boot0.h>
31#else
32	b	reset
33#endif
34
35	.align 3
36
37.globl	_TEXT_BASE
38_TEXT_BASE:
39	.quad	CONFIG_SYS_TEXT_BASE
40
41/*
42 * These are defined in the linker script.
43 */
44.globl	_end_ofs
45_end_ofs:
46	.quad	_end - _start
47
48.globl	_bss_start_ofs
49_bss_start_ofs:
50	.quad	__bss_start - _start
51
52.globl	_bss_end_ofs
53_bss_end_ofs:
54	.quad	__bss_end - _start
55
56reset:
57	/* Allow the board to save important registers */
58	b	save_boot_params
59.globl	save_boot_params_ret
60save_boot_params_ret:
61
62#if CONFIG_POSITION_INDEPENDENT
63	/*
64	 * Fix .rela.dyn relocations. This allows U-Boot to be loaded to and
65	 * executed at a different address than it was linked at.
66	 */
67pie_fixup:
68	adr	x0, _start		/* x0 <- Runtime value of _start */
69	ldr	x1, _TEXT_BASE		/* x1 <- Linked value of _start */
70	sub	x9, x0, x1		/* x9 <- Run-vs-link offset */
71	adr	x2, __rel_dyn_start	/* x2 <- Runtime &__rel_dyn_start */
72	adr	x3, __rel_dyn_end	/* x3 <- Runtime &__rel_dyn_end */
73pie_fix_loop:
74	ldp	x0, x1, [x2], #16	/* (x0, x1) <- (Link location, fixup) */
75	ldr	x4, [x2], #8		/* x4 <- addend */
76	cmp	w1, #1027		/* relative fixup? */
77	bne	pie_skip_reloc
78	/* relative fix: store addend plus offset at dest location */
79	add	x0, x0, x9
80	add	x4, x4, x9
81	str	x4, [x0]
82pie_skip_reloc:
83	cmp	x2, x3
84	b.lo	pie_fix_loop
85pie_fixup_done:
86#endif
87
88#ifdef CONFIG_SYS_RESET_SCTRL
89	bl reset_sctrl
90#endif
91	/*
92	 * Could be EL3/EL2/EL1, Initial State:
93	 * Little Endian, MMU Disabled, i/dCache Disabled
94	 */
95	adr	x0, vectors
96	switch_el x1, 3f, 2f, 1f
973:	msr	vbar_el3, x0
98	mrs	x0, scr_el3
99	orr	x0, x0, #0xf			/* SCR_EL3.NS|IRQ|FIQ|EA */
100	msr	scr_el3, x0
101	msr	cptr_el3, xzr			/* Enable FP/SIMD */
102#ifdef COUNTER_FREQUENCY
103	ldr	x0, =COUNTER_FREQUENCY
104	msr	cntfrq_el0, x0			/* Initialize CNTFRQ */
105#endif
106	b	0f
1072:	msr	vbar_el2, x0
108	mov	x0, #0x33ff
109	msr	cptr_el2, x0			/* Enable FP/SIMD */
110	b	0f
1111:	msr	vbar_el1, x0
112	mov	x0, #3 << 20
113	msr	cpacr_el1, x0			/* Enable FP/SIMD */
1140:
115
116	/*
117	 * Enable SMPEN bit for coherency.
118	 * This register is not architectural but at the moment
119	 * this bit should be set for A53/A57/A72.
120	 */
121#ifdef CONFIG_ARMV8_SET_SMPEN
122	switch_el x1, 3f, 1f, 1f
1233:
124	mrs     x0, S3_1_c15_c2_1               /* cpuectlr_el1 */
125	orr     x0, x0, #0x40
126	msr     S3_1_c15_c2_1, x0
1271:
128#endif
129
130	/* Apply ARM core specific erratas */
131	bl	apply_core_errata
132
133	/*
134	 * Cache/BPB/TLB Invalidate
135	 * i-cache is invalidated before enabled in icache_enable()
136	 * tlb is invalidated before mmu is enabled in dcache_enable()
137	 * d-cache is invalidated before enabled in dcache_enable()
138	 */
139
140	/* Processor specific initialization */
141	bl	lowlevel_init
142
143#if defined(CONFIG_ARMV8_SPIN_TABLE) && !defined(CONFIG_SPL_BUILD)
144	branch_if_master x0, x1, master_cpu
145	b	spin_table_secondary_jump
146	/* never return */
147#elif defined(CONFIG_ARMV8_MULTIENTRY)
148	branch_if_master x0, x1, master_cpu
149
150	/*
151	 * Slave CPUs
152	 */
153slave_cpu:
154	wfe
155	ldr	x1, =CPU_RELEASE_ADDR
156	ldr	x0, [x1]
157	cbz	x0, slave_cpu
158	br	x0			/* branch to the given address */
159#endif /* CONFIG_ARMV8_MULTIENTRY */
160master_cpu:
161	bl	_main
162
163#ifdef CONFIG_SYS_RESET_SCTRL
164reset_sctrl:
165	switch_el x1, 3f, 2f, 1f
1663:
167	mrs	x0, sctlr_el3
168	b	0f
1692:
170	mrs	x0, sctlr_el2
171	b	0f
1721:
173	mrs	x0, sctlr_el1
174
1750:
176	ldr	x1, =0xfdfffffa
177	and	x0, x0, x1
178
179	switch_el x1, 6f, 5f, 4f
1806:
181	msr	sctlr_el3, x0
182	b	7f
1835:
184	msr	sctlr_el2, x0
185	b	7f
1864:
187	msr	sctlr_el1, x0
188
1897:
190	dsb	sy
191	isb
192	b	__asm_invalidate_tlb_all
193	ret
194#endif
195
196/*-----------------------------------------------------------------------*/
197
198WEAK(apply_core_errata)
199
200	mov	x29, lr			/* Save LR */
201	/* For now, we support Cortex-A53, Cortex-A57 specific errata */
202
203	/* Check if we are running on a Cortex-A53 core */
204	branch_if_a53_core x0, apply_a53_core_errata
205
206	/* Check if we are running on a Cortex-A57 core */
207	branch_if_a57_core x0, apply_a57_core_errata
2080:
209	mov	lr, x29			/* Restore LR */
210	ret
211
212apply_a53_core_errata:
213
214#ifdef CONFIG_ARM_ERRATA_855873
215	mrs	x0, midr_el1
216	tst	x0, #(0xf << 20)
217	b.ne	0b
218
219	mrs	x0, midr_el1
220	and	x0, x0, #0xf
221	cmp	x0, #3
222	b.lt	0b
223
224	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
225	/* Enable data cache clean as data cache clean/invalidate */
226	orr	x0, x0, #1 << 44
227	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
228#endif
229	b 0b
230
231apply_a57_core_errata:
232
233#ifdef CONFIG_ARM_ERRATA_828024
234	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
235	/* Disable non-allocate hint of w-b-n-a memory type */
236	orr	x0, x0, #1 << 49
237	/* Disable write streaming no L1-allocate threshold */
238	orr	x0, x0, #3 << 25
239	/* Disable write streaming no-allocate threshold */
240	orr	x0, x0, #3 << 27
241	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
242#endif
243
244#ifdef CONFIG_ARM_ERRATA_826974
245	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
246	/* Disable speculative load execution ahead of a DMB */
247	orr	x0, x0, #1 << 59
248	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
249#endif
250
251#ifdef CONFIG_ARM_ERRATA_833471
252	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
253	/* FPSCR write flush.
254	 * Note that in some cases where a flush is unnecessary this
255	    could impact performance. */
256	orr	x0, x0, #1 << 38
257	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
258#endif
259
260#ifdef CONFIG_ARM_ERRATA_829520
261	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
262	/* Disable Indirect Predictor bit will prevent this erratum
263	    from occurring
264	 * Note that in some cases where a flush is unnecessary this
265	    could impact performance. */
266	orr	x0, x0, #1 << 4
267	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
268#endif
269
270#ifdef CONFIG_ARM_ERRATA_833069
271	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
272	/* Disable Enable Invalidates of BTB bit */
273	and	x0, x0, #0xE
274	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
275#endif
276	b 0b
277ENDPROC(apply_core_errata)
278
279/*-----------------------------------------------------------------------*/
280
281WEAK(lowlevel_init)
282	mov	x29, lr			/* Save LR */
283
284#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3)
285	branch_if_slave x0, 1f
286	ldr	x0, =GICD_BASE
287	bl	gic_init_secure
2881:
289#if defined(CONFIG_GICV3)
290	ldr	x0, =GICR_BASE
291	bl	gic_init_secure_percpu
292#elif defined(CONFIG_GICV2)
293	ldr	x0, =GICD_BASE
294	ldr	x1, =GICC_BASE
295	bl	gic_init_secure_percpu
296#endif
297#endif
298
299#ifdef CONFIG_ARMV8_MULTIENTRY
300	branch_if_master x0, x1, 2f
301
302	/*
303	 * Slave should wait for master clearing spin table.
304	 * This sync prevent salves observing incorrect
305	 * value of spin table and jumping to wrong place.
306	 */
307#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3)
308#ifdef CONFIG_GICV2
309	ldr	x0, =GICC_BASE
310#endif
311	bl	gic_wait_for_interrupt
312#endif
313
314	/*
315	 * All slaves will enter EL2 and optionally EL1.
316	 */
317	adr	x4, lowlevel_in_el2
318	ldr	x5, =ES_TO_AARCH64
319	bl	armv8_switch_to_el2
320
321lowlevel_in_el2:
322#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
323	adr	x4, lowlevel_in_el1
324	ldr	x5, =ES_TO_AARCH64
325	bl	armv8_switch_to_el1
326
327lowlevel_in_el1:
328#endif
329
330#endif /* CONFIG_ARMV8_MULTIENTRY */
331
3322:
333	mov	lr, x29			/* Restore LR */
334	ret
335ENDPROC(lowlevel_init)
336
337WEAK(smp_kick_all_cpus)
338	/* Kick secondary cpus up by SGI 0 interrupt */
339#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3)
340	ldr	x0, =GICD_BASE
341	b	gic_kick_secondary_cpus
342#endif
343	ret
344ENDPROC(smp_kick_all_cpus)
345
346/*-----------------------------------------------------------------------*/
347
348ENTRY(c_runtime_cpu_setup)
349	/* Relocate vBAR */
350	adr	x0, vectors
351	switch_el x1, 3f, 2f, 1f
3523:	msr	vbar_el3, x0
353	b	0f
3542:	msr	vbar_el2, x0
355	b	0f
3561:	msr	vbar_el1, x0
3570:
358
359	ret
360ENDPROC(c_runtime_cpu_setup)
361
362WEAK(save_boot_params)
363	b	save_boot_params_ret	/* back to my caller */
364ENDPROC(save_boot_params)
365