xref: /openbmc/u-boot/arch/arm/cpu/armv8/start.S (revision 12308b12)
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * (C) Copyright 2013
4 * David Feng <fenghua@phytium.com.cn>
5 */
6
7#include <asm-offsets.h>
8#include <config.h>
9#include <linux/linkage.h>
10#include <asm/macro.h>
11#include <asm/armv8/mmu.h>
12
13/*************************************************************************
14 *
15 * Startup Code (reset vector)
16 *
17 *************************************************************************/
18
19.globl	_start
20_start:
21#if defined(LINUX_KERNEL_IMAGE_HEADER)
22#include <asm/boot0-linux-kernel-header.h>
23#elif defined(CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK)
24/*
25 * Various SoCs need something special and SoC-specific up front in
26 * order to boot, allow them to set that in their boot0.h file and then
27 * use it here.
28 */
29#include <asm/arch/boot0.h>
30#else
31	b	reset
32#endif
33
34	.align 3
35
36.globl	_TEXT_BASE
37_TEXT_BASE:
38	.quad	CONFIG_SYS_TEXT_BASE
39
40/*
41 * These are defined in the linker script.
42 */
43.globl	_end_ofs
44_end_ofs:
45	.quad	_end - _start
46
47.globl	_bss_start_ofs
48_bss_start_ofs:
49	.quad	__bss_start - _start
50
51.globl	_bss_end_ofs
52_bss_end_ofs:
53	.quad	__bss_end - _start
54
55reset:
56	/* Allow the board to save important registers */
57	b	save_boot_params
58.globl	save_boot_params_ret
59save_boot_params_ret:
60
61#if CONFIG_POSITION_INDEPENDENT
62	/*
63	 * Fix .rela.dyn relocations. This allows U-Boot to be loaded to and
64	 * executed at a different address than it was linked at.
65	 */
66pie_fixup:
67	adr	x0, _start		/* x0 <- Runtime value of _start */
68	ldr	x1, _TEXT_BASE		/* x1 <- Linked value of _start */
69	sub	x9, x0, x1		/* x9 <- Run-vs-link offset */
70	adr	x2, __rel_dyn_start	/* x2 <- Runtime &__rel_dyn_start */
71	adr	x3, __rel_dyn_end	/* x3 <- Runtime &__rel_dyn_end */
72pie_fix_loop:
73	ldp	x0, x1, [x2], #16	/* (x0, x1) <- (Link location, fixup) */
74	ldr	x4, [x2], #8		/* x4 <- addend */
75	cmp	w1, #1027		/* relative fixup? */
76	bne	pie_skip_reloc
77	/* relative fix: store addend plus offset at dest location */
78	add	x0, x0, x9
79	add	x4, x4, x9
80	str	x4, [x0]
81pie_skip_reloc:
82	cmp	x2, x3
83	b.lo	pie_fix_loop
84pie_fixup_done:
85#endif
86
87#ifdef CONFIG_SYS_RESET_SCTRL
88	bl reset_sctrl
89#endif
90	/*
91	 * Could be EL3/EL2/EL1, Initial State:
92	 * Little Endian, MMU Disabled, i/dCache Disabled
93	 */
94	adr	x0, vectors
95	switch_el x1, 3f, 2f, 1f
963:	msr	vbar_el3, x0
97	mrs	x0, scr_el3
98	orr	x0, x0, #0xf			/* SCR_EL3.NS|IRQ|FIQ|EA */
99	msr	scr_el3, x0
100	msr	cptr_el3, xzr			/* Enable FP/SIMD */
101#ifdef COUNTER_FREQUENCY
102	ldr	x0, =COUNTER_FREQUENCY
103	msr	cntfrq_el0, x0			/* Initialize CNTFRQ */
104#endif
105	b	0f
1062:	msr	vbar_el2, x0
107	mov	x0, #0x33ff
108	msr	cptr_el2, x0			/* Enable FP/SIMD */
109	b	0f
1101:	msr	vbar_el1, x0
111	mov	x0, #3 << 20
112	msr	cpacr_el1, x0			/* Enable FP/SIMD */
1130:
114
115	/*
116	 * Enable SMPEN bit for coherency.
117	 * This register is not architectural but at the moment
118	 * this bit should be set for A53/A57/A72.
119	 */
120#ifdef CONFIG_ARMV8_SET_SMPEN
121	switch_el x1, 3f, 1f, 1f
1223:
123	mrs     x0, S3_1_c15_c2_1               /* cpuectlr_el1 */
124	orr     x0, x0, #0x40
125	msr     S3_1_c15_c2_1, x0
1261:
127#endif
128
129	/* Apply ARM core specific erratas */
130	bl	apply_core_errata
131
132	/*
133	 * Cache/BPB/TLB Invalidate
134	 * i-cache is invalidated before enabled in icache_enable()
135	 * tlb is invalidated before mmu is enabled in dcache_enable()
136	 * d-cache is invalidated before enabled in dcache_enable()
137	 */
138
139	/* Processor specific initialization */
140	bl	lowlevel_init
141
142#if defined(CONFIG_ARMV8_SPIN_TABLE) && !defined(CONFIG_SPL_BUILD)
143	branch_if_master x0, x1, master_cpu
144	b	spin_table_secondary_jump
145	/* never return */
146#elif defined(CONFIG_ARMV8_MULTIENTRY)
147	branch_if_master x0, x1, master_cpu
148
149	/*
150	 * Slave CPUs
151	 */
152slave_cpu:
153	wfe
154	ldr	x1, =CPU_RELEASE_ADDR
155	ldr	x0, [x1]
156	cbz	x0, slave_cpu
157	br	x0			/* branch to the given address */
158#endif /* CONFIG_ARMV8_MULTIENTRY */
159master_cpu:
160	bl	_main
161
162#ifdef CONFIG_SYS_RESET_SCTRL
163reset_sctrl:
164	switch_el x1, 3f, 2f, 1f
1653:
166	mrs	x0, sctlr_el3
167	b	0f
1682:
169	mrs	x0, sctlr_el2
170	b	0f
1711:
172	mrs	x0, sctlr_el1
173
1740:
175	ldr	x1, =0xfdfffffa
176	and	x0, x0, x1
177
178	switch_el x1, 6f, 5f, 4f
1796:
180	msr	sctlr_el3, x0
181	b	7f
1825:
183	msr	sctlr_el2, x0
184	b	7f
1854:
186	msr	sctlr_el1, x0
187
1887:
189	dsb	sy
190	isb
191	b	__asm_invalidate_tlb_all
192	ret
193#endif
194
195/*-----------------------------------------------------------------------*/
196
197WEAK(apply_core_errata)
198
199	mov	x29, lr			/* Save LR */
200	/* For now, we support Cortex-A53, Cortex-A57 specific errata */
201
202	/* Check if we are running on a Cortex-A53 core */
203	branch_if_a53_core x0, apply_a53_core_errata
204
205	/* Check if we are running on a Cortex-A57 core */
206	branch_if_a57_core x0, apply_a57_core_errata
2070:
208	mov	lr, x29			/* Restore LR */
209	ret
210
211apply_a53_core_errata:
212
213#ifdef CONFIG_ARM_ERRATA_855873
214	mrs	x0, midr_el1
215	tst	x0, #(0xf << 20)
216	b.ne	0b
217
218	mrs	x0, midr_el1
219	and	x0, x0, #0xf
220	cmp	x0, #3
221	b.lt	0b
222
223	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
224	/* Enable data cache clean as data cache clean/invalidate */
225	orr	x0, x0, #1 << 44
226	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
227#endif
228	b 0b
229
230apply_a57_core_errata:
231
232#ifdef CONFIG_ARM_ERRATA_828024
233	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
234	/* Disable non-allocate hint of w-b-n-a memory type */
235	orr	x0, x0, #1 << 49
236	/* Disable write streaming no L1-allocate threshold */
237	orr	x0, x0, #3 << 25
238	/* Disable write streaming no-allocate threshold */
239	orr	x0, x0, #3 << 27
240	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
241#endif
242
243#ifdef CONFIG_ARM_ERRATA_826974
244	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
245	/* Disable speculative load execution ahead of a DMB */
246	orr	x0, x0, #1 << 59
247	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
248#endif
249
250#ifdef CONFIG_ARM_ERRATA_833471
251	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
252	/* FPSCR write flush.
253	 * Note that in some cases where a flush is unnecessary this
254	    could impact performance. */
255	orr	x0, x0, #1 << 38
256	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
257#endif
258
259#ifdef CONFIG_ARM_ERRATA_829520
260	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
261	/* Disable Indirect Predictor bit will prevent this erratum
262	    from occurring
263	 * Note that in some cases where a flush is unnecessary this
264	    could impact performance. */
265	orr	x0, x0, #1 << 4
266	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
267#endif
268
269#ifdef CONFIG_ARM_ERRATA_833069
270	mrs	x0, S3_1_c15_c2_0	/* cpuactlr_el1 */
271	/* Disable Enable Invalidates of BTB bit */
272	and	x0, x0, #0xE
273	msr	S3_1_c15_c2_0, x0	/* cpuactlr_el1 */
274#endif
275	b 0b
276ENDPROC(apply_core_errata)
277
278/*-----------------------------------------------------------------------*/
279
280WEAK(lowlevel_init)
281	mov	x29, lr			/* Save LR */
282
283#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3)
284	branch_if_slave x0, 1f
285	ldr	x0, =GICD_BASE
286	bl	gic_init_secure
2871:
288#if defined(CONFIG_GICV3)
289	ldr	x0, =GICR_BASE
290	bl	gic_init_secure_percpu
291#elif defined(CONFIG_GICV2)
292	ldr	x0, =GICD_BASE
293	ldr	x1, =GICC_BASE
294	bl	gic_init_secure_percpu
295#endif
296#endif
297
298#ifdef CONFIG_ARMV8_MULTIENTRY
299	branch_if_master x0, x1, 2f
300
301	/*
302	 * Slave should wait for master clearing spin table.
303	 * This sync prevent salves observing incorrect
304	 * value of spin table and jumping to wrong place.
305	 */
306#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3)
307#ifdef CONFIG_GICV2
308	ldr	x0, =GICC_BASE
309#endif
310	bl	gic_wait_for_interrupt
311#endif
312
313	/*
314	 * All slaves will enter EL2 and optionally EL1.
315	 */
316	adr	x4, lowlevel_in_el2
317	ldr	x5, =ES_TO_AARCH64
318	bl	armv8_switch_to_el2
319
320lowlevel_in_el2:
321#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
322	adr	x4, lowlevel_in_el1
323	ldr	x5, =ES_TO_AARCH64
324	bl	armv8_switch_to_el1
325
326lowlevel_in_el1:
327#endif
328
329#endif /* CONFIG_ARMV8_MULTIENTRY */
330
3312:
332	mov	lr, x29			/* Restore LR */
333	ret
334ENDPROC(lowlevel_init)
335
336WEAK(smp_kick_all_cpus)
337	/* Kick secondary cpus up by SGI 0 interrupt */
338#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3)
339	ldr	x0, =GICD_BASE
340	b	gic_kick_secondary_cpus
341#endif
342	ret
343ENDPROC(smp_kick_all_cpus)
344
345/*-----------------------------------------------------------------------*/
346
347ENTRY(c_runtime_cpu_setup)
348	/* Relocate vBAR */
349	adr	x0, vectors
350	switch_el x1, 3f, 2f, 1f
3513:	msr	vbar_el3, x0
352	b	0f
3532:	msr	vbar_el2, x0
354	b	0f
3551:	msr	vbar_el1, x0
3560:
357
358	ret
359ENDPROC(c_runtime_cpu_setup)
360
361WEAK(save_boot_params)
362	b	save_boot_params_ret	/* back to my caller */
363ENDPROC(save_boot_params)
364