1 /* SPDX-License-Identifier: GPL-2.0+ */ 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 got MM problems and 16 * printk isn't working). For DEBUGGING ONLY!!! Do not leave 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, tmp1, tmp2 26 addruart \tmp1, \tmp2, \rx 27 mrc p15, 0, \rx, c1, c0 28 tst \rx, #1 29 moveq \rx, \tmp1 30 movne \rx, \tmp2 31 .endm 32 33 #else /* !CONFIG_MMU */ 34 .macro addruart_current, rx, tmp1, tmp2 35 addruart \rx, \tmp1, \tmp2 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 56 add r3, r2, r1 57 mov r1, #0 58 strb r1, [r3] 59 1: and r1, r0, #15 60 mov r0, r0, lsr #4 61 cmp r1, #10 62 addlt r1, r1, #'0' 63 addge r1, r1, #'a' - 10 64 strb r1, [r3, #-1]! 65 teq r3, r2 66 bne 1b 67 mov r0, r2 68 b printascii 69 ENDPROC(printhex2) 70 71 hexbuf: .space 16 72 73 .ltorg 74 75 #ifndef CONFIG_DEBUG_SEMIHOSTING 76 77 ENTRY(printascii) 78 addruart_current r3, r1, r2 79 b 2f 80 1: waituart r2, r3 81 senduart r1, r3 82 busyuart r2, r3 83 teq r1, #'\n' 84 moveq r1, #'\r' 85 beq 1b 86 2: teq r0, #0 87 ldrneb r1, [r0], #1 88 teqne r1, #0 89 bne 1b 90 mov pc, lr 91 ENDPROC(printascii) 92 93 ENTRY(printch) 94 addruart_current r3, r1, r2 95 mov r1, r0 96 mov r0, #0 97 b 1b 98 ENDPROC(printch) 99 100 #ifdef CONFIG_MMU 101 ENTRY(debug_ll_addr) 102 addruart r2, r3, ip 103 str r2, [r0] 104 str r3, [r1] 105 mov pc, lr 106 ENDPROC(debug_ll_addr) 107 #endif 108 109 #else 110 111 ENTRY(printascii) 112 mov r1, r0 113 mov r0, #0x04 @ SYS_WRITE0 114 ARM( svc #0x123456 ) 115 THUMB( svc #0xab ) 116 mov pc, lr 117 ENDPROC(printascii) 118 119 ENTRY(printch) 120 adr r1, hexbuf 121 strb r0, [r1] 122 mov r0, #0x03 @ SYS_WRITEC 123 ARM( svc #0x123456 ) 124 THUMB( svc #0xab ) 125 mov pc, lr 126 ENDPROC(printch) 127 128 ENTRY(debug_ll_addr) 129 mov r2, #0 130 str r2, [r0] 131 str r2, [r1] 132 mov pc, lr 133 ENDPROC(debug_ll_addr) 134 135 #endif 136
