xref: /openbmc/u-boot/arch/arm/lib/vectors.S (revision 407b5b956a2e0facf6668fc8b295f4be9205c83e)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  *  vectors - Generic ARM exception table code
4  *
5  *  Copyright (c) 1998	Dan Malek <dmalek@jlc.net>
6  *  Copyright (c) 1999	Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
7  *  Copyright (c) 2000	Wolfgang Denk <wd@denx.de>
8  *  Copyright (c) 2001	Alex Züpke <azu@sysgo.de>
9  *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
10  *  Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
11  *  Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
12  *  Copyright (c) 2002	Kyle Harris <kharris@nexus-tech.net>
13  */
14 
15 #include <config.h>
16 
17 /*
18  * A macro to allow insertion of an ARM exception vector either
19  * for the non-boot0 case or by a boot0-header.
20  */
21         .macro ARM_VECTORS
22 #ifdef CONFIG_ARCH_K3
23 	ldr     pc, _reset
24 #else
25 	b	reset
26 #endif
27 	ldr	pc, _undefined_instruction
28 	ldr	pc, _software_interrupt
29 	ldr	pc, _prefetch_abort
30 	ldr	pc, _data_abort
31 	ldr	pc, _not_used
32 	ldr	pc, _irq
33 	ldr	pc, _fiq
34 	.endm
35 
36 
37 /*
38  *************************************************************************
39  *
40  * Symbol _start is referenced elsewhere, so make it global
41  *
42  *************************************************************************
43  */
44 
45 .globl _start
46 
47 /*
48  *************************************************************************
49  *
50  * Vectors have their own section so linker script can map them easily
51  *
52  *************************************************************************
53  */
54 
55 	.section ".vectors", "ax"
56 
57 #if defined(CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK)
58 /*
59  * Various SoCs need something special and SoC-specific up front in
60  * order to boot, allow them to set that in their boot0.h file and then
61  * use it here.
62  *
63  * To allow a boot0 hook to insert a 'special' sequence after the vector
64  * table (e.g. for the socfpga), the presence of a boot0 hook supresses
65  * the below vector table and assumes that the vector table is filled in
66  * by the boot0 hook.  The requirements for a boot0 hook thus are:
67  *   (1) defines '_start:' as appropriate
68  *   (2) inserts the vector table using ARM_VECTORS as appropriate
69  */
70 #include <asm/arch/boot0.h>
71 
72 #else
73 
74 /*
75  *************************************************************************
76  *
77  * Exception vectors as described in ARM reference manuals
78  *
79  * Uses indirect branch to allow reaching handlers anywhere in memory.
80  *
81  *************************************************************************
82  */
83 
84 _start:
85 #ifdef CONFIG_SYS_DV_NOR_BOOT_CFG
86 	.word	CONFIG_SYS_DV_NOR_BOOT_CFG
87 #endif
88 	ARM_VECTORS
89 #endif /* !defined(CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK) */
90 
91 /*
92  *************************************************************************
93  *
94  * Indirect vectors table
95  *
96  * Symbols referenced here must be defined somewhere else
97  *
98  *************************************************************************
99  */
100 
101 	.globl  _reset
102 	.globl	_undefined_instruction
103 	.globl	_software_interrupt
104 	.globl	_prefetch_abort
105 	.globl	_data_abort
106 	.globl	_not_used
107 	.globl	_irq
108 	.globl	_fiq
109 
110 #ifdef CONFIG_ARCH_K3
111 _reset:			.word reset
112 #endif
113 _undefined_instruction:	.word undefined_instruction
114 _software_interrupt:	.word software_interrupt
115 _prefetch_abort:	.word prefetch_abort
116 _data_abort:		.word data_abort
117 _not_used:		.word not_used
118 _irq:			.word irq
119 _fiq:			.word fiq
120 
121 	.balignl 16,0xdeadbeef
122 
123 /*
124  *************************************************************************
125  *
126  * Interrupt handling
127  *
128  *************************************************************************
129  */
130 
131 /* SPL interrupt handling: just hang */
132 
133 #ifdef CONFIG_SPL_BUILD
134 
135 	.align	5
136 undefined_instruction:
137 software_interrupt:
138 prefetch_abort:
139 data_abort:
140 not_used:
141 irq:
142 fiq:
143 1:
144 	b	1b			/* hang and never return */
145 
146 #else	/* !CONFIG_SPL_BUILD */
147 
148 /* IRQ stack memory (calculated at run-time) + 8 bytes */
149 .globl IRQ_STACK_START_IN
150 IRQ_STACK_START_IN:
151 #ifdef IRAM_BASE_ADDR
152 	.word   IRAM_BASE_ADDR + 0x20
153 #else
154 	.word	0x0badc0de
155 #endif
156 
157 @
158 @ IRQ stack frame.
159 @
160 #define S_FRAME_SIZE	72
161 
162 #define S_OLD_R0	68
163 #define S_PSR		64
164 #define S_PC		60
165 #define S_LR		56
166 #define S_SP		52
167 
168 #define S_IP		48
169 #define S_FP		44
170 #define S_R10		40
171 #define S_R9		36
172 #define S_R8		32
173 #define S_R7		28
174 #define S_R6		24
175 #define S_R5		20
176 #define S_R4		16
177 #define S_R3		12
178 #define S_R2		8
179 #define S_R1		4
180 #define S_R0		0
181 
182 #define MODE_SVC 0x13
183 #define I_BIT	 0x80
184 
185 /*
186  * use bad_save_user_regs for abort/prefetch/undef/swi ...
187  * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
188  */
189 
190 	.macro	bad_save_user_regs
191 	@ carve out a frame on current user stack
192 	sub	sp, sp, #S_FRAME_SIZE
193 	stmia	sp, {r0 - r12}	@ Save user registers (now in svc mode) r0-r12
194 	ldr	r2, IRQ_STACK_START_IN
195 	@ get values for "aborted" pc and cpsr (into parm regs)
196 	ldmia	r2, {r2 - r3}
197 	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
198 	add	r5, sp, #S_SP
199 	mov	r1, lr
200 	stmia	r5, {r0 - r3}	@ save sp_SVC, lr_SVC, pc, cpsr
201 	mov	r0, sp		@ save current stack into r0 (param register)
202 	.endm
203 
204 	.macro	irq_save_user_regs
205 	sub	sp, sp, #S_FRAME_SIZE
206 	stmia	sp, {r0 - r12}			@ Calling r0-r12
207 	@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
208 	add	r8, sp, #S_PC
209 	stmdb	r8, {sp, lr}^		@ Calling SP, LR
210 	str	lr, [r8, #0]		@ Save calling PC
211 	mrs	r6, spsr
212 	str	r6, [r8, #4]		@ Save CPSR
213 	str	r0, [r8, #8]		@ Save OLD_R0
214 	mov	r0, sp
215 	.endm
216 
217 	.macro	irq_restore_user_regs
218 	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
219 	mov	r0, r0
220 	ldr	lr, [sp, #S_PC]			@ Get PC
221 	add	sp, sp, #S_FRAME_SIZE
222 	subs	pc, lr, #4		@ return & move spsr_svc into cpsr
223 	.endm
224 
225 	.macro get_bad_stack
226 	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
227 
228 	str	lr, [r13]	@ save caller lr in position 0 of saved stack
229 	mrs	lr, spsr	@ get the spsr
230 	str	lr, [r13, #4]	@ save spsr in position 1 of saved stack
231 	mov	r13, #MODE_SVC	@ prepare SVC-Mode
232 	@ msr	spsr_c, r13
233 	msr	spsr, r13	@ switch modes, make sure moves will execute
234 	mov	lr, pc		@ capture return pc
235 	movs	pc, lr		@ jump to next instruction & switch modes.
236 	.endm
237 
238 	.macro get_irq_stack			@ setup IRQ stack
239 	ldr	sp, IRQ_STACK_START
240 	.endm
241 
242 	.macro get_fiq_stack			@ setup FIQ stack
243 	ldr	sp, FIQ_STACK_START
244 	.endm
245 
246 /*
247  * exception handlers
248  */
249 
250 	.align  5
251 undefined_instruction:
252 	get_bad_stack
253 	bad_save_user_regs
254 	bl	do_undefined_instruction
255 
256 	.align	5
257 software_interrupt:
258 	get_bad_stack
259 	bad_save_user_regs
260 	bl	do_software_interrupt
261 
262 	.align	5
263 prefetch_abort:
264 	get_bad_stack
265 	bad_save_user_regs
266 	bl	do_prefetch_abort
267 
268 	.align	5
269 data_abort:
270 	get_bad_stack
271 	bad_save_user_regs
272 	bl	do_data_abort
273 
274 	.align	5
275 not_used:
276 	get_bad_stack
277 	bad_save_user_regs
278 	bl	do_not_used
279 
280 
281 	.align	5
282 irq:
283 	get_bad_stack
284 	bad_save_user_regs
285 	bl	do_irq
286 
287 	.align	5
288 fiq:
289 	get_bad_stack
290 	bad_save_user_regs
291 	bl	do_fiq
292 
293 #endif	/* CONFIG_SPL_BUILD */
294