xref: /openbmc/u-boot/arch/arm/lib/vectors.S (revision 17fa0326) 
1/*
2 *  vectors - Generic ARM exception table code
3 *
4 *  Copyright (c) 1998	Dan Malek <dmalek@jlc.net>
5 *  Copyright (c) 1999	Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
6 *  Copyright (c) 2000	Wolfgang Denk <wd@denx.de>
7 *  Copyright (c) 2001	Alex Züpke <azu@sysgo.de>
8 *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
9 *  Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
10 *  Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
11 *  Copyright (c) 2002	Kyle Harris <kharris@nexus-tech.net>
12 *
13 * SPDX-License-Identifier:	GPL-2.0+
14 */
15
16#include <config.h>
17
18/*
19 *************************************************************************
20 *
21 * Symbol _start is referenced elsewhere, so make it global
22 *
23 *************************************************************************
24 */
25
26.globl _start
27
28/*
29 *************************************************************************
30 *
31 * Vectors have their own section so linker script can map them easily
32 *
33 *************************************************************************
34 */
35
36	.section ".vectors", "ax"
37
38/*
39 *************************************************************************
40 *
41 * Exception vectors as described in ARM reference manuals
42 *
43 * Uses indirect branch to allow reaching handlers anywhere in memory.
44 *
45 *************************************************************************
46 */
47
48_start:
49
50#ifdef CONFIG_SYS_DV_NOR_BOOT_CFG
51	.word	CONFIG_SYS_DV_NOR_BOOT_CFG
52#endif
53
54	b	reset
55	ldr	pc, _undefined_instruction
56	ldr	pc, _software_interrupt
57	ldr	pc, _prefetch_abort
58	ldr	pc, _data_abort
59	ldr	pc, _not_used
60	ldr	pc, _irq
61	ldr	pc, _fiq
62
63#ifdef CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK
64/*
65 * Various SoCs need something special and SoC-specific up front in
66 * order to boot, allow them to set that in their boot0.h file and then
67 * use it here.
68 */
69#include <asm/arch/boot0.h>
70#endif
71
72/*
73 *************************************************************************
74 *
75 * Indirect vectors table
76 *
77 * Symbols referenced here must be defined somewhere else
78 *
79 *************************************************************************
80 */
81
82	.globl	_undefined_instruction
83	.globl	_software_interrupt
84	.globl	_prefetch_abort
85	.globl	_data_abort
86	.globl	_not_used
87	.globl	_irq
88	.globl	_fiq
89
90_undefined_instruction:	.word undefined_instruction
91_software_interrupt:	.word software_interrupt
92_prefetch_abort:	.word prefetch_abort
93_data_abort:		.word data_abort
94_not_used:		.word not_used
95_irq:			.word irq
96_fiq:			.word fiq
97
98	.balignl 16,0xdeadbeef
99
100/*
101 *************************************************************************
102 *
103 * Interrupt handling
104 *
105 *************************************************************************
106 */
107
108/* SPL interrupt handling: just hang */
109
110#ifdef CONFIG_SPL_BUILD
111
112	.align	5
113undefined_instruction:
114software_interrupt:
115prefetch_abort:
116data_abort:
117not_used:
118irq:
119fiq:
120
1211:
122	bl	1b			/* hang and never return */
123
124#else	/* !CONFIG_SPL_BUILD */
125
126/* IRQ stack memory (calculated at run-time) + 8 bytes */
127.globl IRQ_STACK_START_IN
128IRQ_STACK_START_IN:
129	.word	0x0badc0de
130
131#ifdef CONFIG_USE_IRQ
132/* IRQ stack memory (calculated at run-time) */
133.globl IRQ_STACK_START
134IRQ_STACK_START:
135	.word	0x0badc0de
136
137/* IRQ stack memory (calculated at run-time) */
138.globl FIQ_STACK_START
139FIQ_STACK_START:
140	.word 0x0badc0de
141
142#endif /* CONFIG_USE_IRQ */
143
144@
145@ IRQ stack frame.
146@
147#define S_FRAME_SIZE	72
148
149#define S_OLD_R0	68
150#define S_PSR		64
151#define S_PC		60
152#define S_LR		56
153#define S_SP		52
154
155#define S_IP		48
156#define S_FP		44
157#define S_R10		40
158#define S_R9		36
159#define S_R8		32
160#define S_R7		28
161#define S_R6		24
162#define S_R5		20
163#define S_R4		16
164#define S_R3		12
165#define S_R2		8
166#define S_R1		4
167#define S_R0		0
168
169#define MODE_SVC 0x13
170#define I_BIT	 0x80
171
172/*
173 * use bad_save_user_regs for abort/prefetch/undef/swi ...
174 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
175 */
176
177	.macro	bad_save_user_regs
178	@ carve out a frame on current user stack
179	sub	sp, sp, #S_FRAME_SIZE
180	stmia	sp, {r0 - r12}	@ Save user registers (now in svc mode) r0-r12
181	ldr	r2, IRQ_STACK_START_IN
182	@ get values for "aborted" pc and cpsr (into parm regs)
183	ldmia	r2, {r2 - r3}
184	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
185	add	r5, sp, #S_SP
186	mov	r1, lr
187	stmia	r5, {r0 - r3}	@ save sp_SVC, lr_SVC, pc, cpsr
188	mov	r0, sp		@ save current stack into r0 (param register)
189	.endm
190
191	.macro	irq_save_user_regs
192	sub	sp, sp, #S_FRAME_SIZE
193	stmia	sp, {r0 - r12}			@ Calling r0-r12
194	@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
195	add	r8, sp, #S_PC
196	stmdb	r8, {sp, lr}^		@ Calling SP, LR
197	str	lr, [r8, #0]		@ Save calling PC
198	mrs	r6, spsr
199	str	r6, [r8, #4]		@ Save CPSR
200	str	r0, [r8, #8]		@ Save OLD_R0
201	mov	r0, sp
202	.endm
203
204	.macro	irq_restore_user_regs
205	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
206	mov	r0, r0
207	ldr	lr, [sp, #S_PC]			@ Get PC
208	add	sp, sp, #S_FRAME_SIZE
209	subs	pc, lr, #4		@ return & move spsr_svc into cpsr
210	.endm
211
212	.macro get_bad_stack
213	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
214
215	str	lr, [r13]	@ save caller lr in position 0 of saved stack
216	mrs	lr, spsr	@ get the spsr
217	str	lr, [r13, #4]	@ save spsr in position 1 of saved stack
218	mov	r13, #MODE_SVC	@ prepare SVC-Mode
219	@ msr	spsr_c, r13
220	msr	spsr, r13	@ switch modes, make sure moves will execute
221	mov	lr, pc		@ capture return pc
222	movs	pc, lr		@ jump to next instruction & switch modes.
223	.endm
224
225	.macro get_irq_stack			@ setup IRQ stack
226	ldr	sp, IRQ_STACK_START
227	.endm
228
229	.macro get_fiq_stack			@ setup FIQ stack
230	ldr	sp, FIQ_STACK_START
231	.endm
232
233/*
234 * exception handlers
235 */
236
237	.align  5
238undefined_instruction:
239	get_bad_stack
240	bad_save_user_regs
241	bl	do_undefined_instruction
242
243	.align	5
244software_interrupt:
245	get_bad_stack
246	bad_save_user_regs
247	bl	do_software_interrupt
248
249	.align	5
250prefetch_abort:
251	get_bad_stack
252	bad_save_user_regs
253	bl	do_prefetch_abort
254
255	.align	5
256data_abort:
257	get_bad_stack
258	bad_save_user_regs
259	bl	do_data_abort
260
261	.align	5
262not_used:
263	get_bad_stack
264	bad_save_user_regs
265	bl	do_not_used
266
267#ifdef CONFIG_USE_IRQ
268
269	.align	5
270irq:
271	get_irq_stack
272	irq_save_user_regs
273	bl	do_irq
274	irq_restore_user_regs
275
276	.align	5
277fiq:
278	get_fiq_stack
279	/* someone ought to write a more effiction fiq_save_user_regs */
280	irq_save_user_regs
281	bl	do_fiq
282	irq_restore_user_regs
283
284#else
285
286	.align	5
287irq:
288	get_bad_stack
289	bad_save_user_regs
290	bl	do_irq
291
292	.align	5
293fiq:
294	get_bad_stack
295	bad_save_user_regs
296	bl	do_fiq
297
298#endif /* CONFIG_USE_IRQ */
299
300#endif	/* CONFIG_SPL_BUILD */
301