xref: /openbmc/u-boot/arch/arm/lib/vectors.S (revision 5994e8b6) 
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:
1201:
121	bl	1b			/* hang and never return */
122
123#else	/* !CONFIG_SPL_BUILD */
124
125/* IRQ stack memory (calculated at run-time) + 8 bytes */
126.globl IRQ_STACK_START_IN
127IRQ_STACK_START_IN:
128#ifdef IRAM_BASE_ADDR
129	.word   IRAM_BASE_ADDR + 0x20
130#else
131	.word	0x0badc0de
132#endif
133
134@
135@ IRQ stack frame.
136@
137#define S_FRAME_SIZE	72
138
139#define S_OLD_R0	68
140#define S_PSR		64
141#define S_PC		60
142#define S_LR		56
143#define S_SP		52
144
145#define S_IP		48
146#define S_FP		44
147#define S_R10		40
148#define S_R9		36
149#define S_R8		32
150#define S_R7		28
151#define S_R6		24
152#define S_R5		20
153#define S_R4		16
154#define S_R3		12
155#define S_R2		8
156#define S_R1		4
157#define S_R0		0
158
159#define MODE_SVC 0x13
160#define I_BIT	 0x80
161
162/*
163 * use bad_save_user_regs for abort/prefetch/undef/swi ...
164 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
165 */
166
167	.macro	bad_save_user_regs
168	@ carve out a frame on current user stack
169	sub	sp, sp, #S_FRAME_SIZE
170	stmia	sp, {r0 - r12}	@ Save user registers (now in svc mode) r0-r12
171	ldr	r2, IRQ_STACK_START_IN
172	@ get values for "aborted" pc and cpsr (into parm regs)
173	ldmia	r2, {r2 - r3}
174	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
175	add	r5, sp, #S_SP
176	mov	r1, lr
177	stmia	r5, {r0 - r3}	@ save sp_SVC, lr_SVC, pc, cpsr
178	mov	r0, sp		@ save current stack into r0 (param register)
179	.endm
180
181	.macro	irq_save_user_regs
182	sub	sp, sp, #S_FRAME_SIZE
183	stmia	sp, {r0 - r12}			@ Calling r0-r12
184	@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
185	add	r8, sp, #S_PC
186	stmdb	r8, {sp, lr}^		@ Calling SP, LR
187	str	lr, [r8, #0]		@ Save calling PC
188	mrs	r6, spsr
189	str	r6, [r8, #4]		@ Save CPSR
190	str	r0, [r8, #8]		@ Save OLD_R0
191	mov	r0, sp
192	.endm
193
194	.macro	irq_restore_user_regs
195	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
196	mov	r0, r0
197	ldr	lr, [sp, #S_PC]			@ Get PC
198	add	sp, sp, #S_FRAME_SIZE
199	subs	pc, lr, #4		@ return & move spsr_svc into cpsr
200	.endm
201
202	.macro get_bad_stack
203	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
204
205	str	lr, [r13]	@ save caller lr in position 0 of saved stack
206	mrs	lr, spsr	@ get the spsr
207	str	lr, [r13, #4]	@ save spsr in position 1 of saved stack
208	mov	r13, #MODE_SVC	@ prepare SVC-Mode
209	@ msr	spsr_c, r13
210	msr	spsr, r13	@ switch modes, make sure moves will execute
211	mov	lr, pc		@ capture return pc
212	movs	pc, lr		@ jump to next instruction & switch modes.
213	.endm
214
215	.macro get_irq_stack			@ setup IRQ stack
216	ldr	sp, IRQ_STACK_START
217	.endm
218
219	.macro get_fiq_stack			@ setup FIQ stack
220	ldr	sp, FIQ_STACK_START
221	.endm
222
223/*
224 * exception handlers
225 */
226
227	.align  5
228undefined_instruction:
229	get_bad_stack
230	bad_save_user_regs
231	bl	do_undefined_instruction
232
233	.align	5
234software_interrupt:
235	get_bad_stack
236	bad_save_user_regs
237	bl	do_software_interrupt
238
239	.align	5
240prefetch_abort:
241	get_bad_stack
242	bad_save_user_regs
243	bl	do_prefetch_abort
244
245	.align	5
246data_abort:
247	get_bad_stack
248	bad_save_user_regs
249	bl	do_data_abort
250
251	.align	5
252not_used:
253	get_bad_stack
254	bad_save_user_regs
255	bl	do_not_used
256
257
258	.align	5
259irq:
260	get_bad_stack
261	bad_save_user_regs
262	bl	do_irq
263
264	.align	5
265fiq:
266	get_bad_stack
267	bad_save_user_regs
268	bl	do_fiq
269
270#endif	/* CONFIG_SPL_BUILD */
271