1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * linux/arch/arm/kernel/debug.S
4 *
5 * Copyright (C) 1994-1999 Russell King
6 *
7 * 32-bit debugging code
8 */
9 #include <linux/linkage.h>
10 #include <asm/assembler.h>
11
12 .text
13
14 /*
15 * Some debugging routines (useful if you've g
16 * printk isn't working). For DEBUGGING ONLY!
17 * references to these in a production kernel!
18 */
19
20 #if !defined(CONFIG_DEBUG_SEMIHOSTING)
21 #include CONFIG_DEBUG_LL_INCLUDE
22 #endif
23
24 #ifdef CONFIG_MMU
25 .macro addruart_current, rx,
26 addruart \tmp1, \tmp2,
27 mrc p15, 0, \rx, c
28 tst \rx, #1
29 moveq \rx, \tmp1
30 movne \rx, \tmp2
31 .endm
32
33 #else /* !CONFIG_MMU */
34 .macro addruart_current, rx,
35 addruart \rx, \tmp1, \t
36 .endm
37
38 #endif /* CONFIG_MMU */
39
40 /*
41 * Useful debugging routines
42 */
43 ENTRY(printhex8)
44 mov r1, #8
45 b printhex
46 ENDPROC(printhex8)
47
48 ENTRY(printhex4)
49 mov r1, #4
50 b printhex
51 ENDPROC(printhex4)
52
53 ENTRY(printhex2)
54 mov r1, #2
55 printhex: adr r2, hexbuf_rel
56 ldr r3, [r2]
57 add r2, r2, r3
58 add r3, r2, r1
59 mov r1, #0
60 strb r1, [r3]
61 1: and r1, r0, #15
62 mov r0, r0, lsr #4
63 cmp r1, #10
64 addlt r1, r1, #'0'
65 addge r1, r1, #'a' - 10
66 strb r1, [r3, #-1]!
67 teq r3, r2
68 bne 1b
69 mov r0, r2
70 b printascii
71 ENDPROC(printhex2)
72
73 .pushsection .bss
74 hexbuf_addr: .space 16
75 .popsection
76 .align
77 hexbuf_rel: .long hexbuf_addr - .
78
79 .ltorg
80
81 #ifndef CONFIG_DEBUG_SEMIHOSTING
82
83 ENTRY(printascii)
84 addruart_current r3, r1, r2
85 1: teq r0, #0
86 ldrbne r1, [r0], #1
87 teqne r1, #0
88 reteq lr
89 2: teq r1, #'\n'
90 bne 3f
91 mov r1, #'\r'
92 #ifdef CONFIG_DEBUG_UART_FLOW_CONTROL
93 waituartcts r2, r3
94 #endif
95 waituarttxrdy r2, r3
96 senduart r1, r3
97 busyuart r2, r3
98 mov r1, #'\n'
99 3:
100 #ifdef CONFIG_DEBUG_UART_FLOW_CONTROL
101 waituartcts r2, r3
102 #endif
103 waituarttxrdy r2, r3
104 senduart r1, r3
105 busyuart r2, r3
106 b 1b
107 ENDPROC(printascii)
108
109 ENTRY(printch)
110 addruart_current r3, r1, r2
111 mov r1, r0
112 mov r0, #0
113 b 2b
114 ENDPROC(printch)
115
116 #ifdef CONFIG_MMU
117 ENTRY(debug_ll_addr)
118 addruart r2, r3, ip
119 str r2, [r0]
120 str r3, [r1]
121 ret lr
122 ENDPROC(debug_ll_addr)
123 #endif
124
125 #else
126
127 ENTRY(printascii)
128 mov r1, r0
129 mov r0, #0x04
130 ARM( svc #0x123456 )
131 #ifdef CONFIG_CPU_V7M
132 THUMB( bkpt #0xab )
133 #else
134 THUMB( svc #0xab )
135 #endif
136 ret lr
137 ENDPROC(printascii)
138
139 ENTRY(printch)
140 adr r1, hexbuf_rel
141 ldr r2, [r1]
142 add r1, r1, r2
143 strb r0, [r1]
144 mov r0, #0x03
145 ARM( svc #0x123456 )
146 #ifdef CONFIG_CPU_V7M
147 THUMB( bkpt #0xab )
148 #else
149 THUMB( svc #0xab )
150 #endif
151 ret lr
152 ENDPROC(printch)
153
154 ENTRY(debug_ll_addr)
155 mov r2, #0
156 str r2, [r0]
157 str r2, [r1]
158 ret lr
159 ENDPROC(debug_ll_addr)
160
161 #endif
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