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 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 */ 43ENTRY(printhex8) 44 mov r1, #8 45 b printhex 46ENDPROC(printhex8) 47 48ENTRY(printhex4) 49 mov r1, #4 50 b printhex 51ENDPROC(printhex4) 52 53ENTRY(printhex2) 54 mov r1, #2 55printhex: 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] 611: 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 71ENDPROC(printhex2) 72 73 .pushsection .bss 74hexbuf_addr: .space 16 75 .popsection 76 .align 77hexbuf_rel: .long hexbuf_addr - . 78 79 .ltorg 80 81#ifndef CONFIG_DEBUG_SEMIHOSTING 82 83ENTRY(printascii) 84 addruart_current r3, r1, r2 851: teq r0, #0 86 ldrbne r1, [r0], #1 87 teqne r1, #0 88 reteq lr 892: 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' 993: 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 107ENDPROC(printascii) 108 109ENTRY(printch) 110 addruart_current r3, r1, r2 111 mov r1, r0 112 mov r0, #0 113 b 2b 114ENDPROC(printch) 115 116#ifdef CONFIG_MMU 117ENTRY(debug_ll_addr) 118 addruart r2, r3, ip 119 str r2, [r0] 120 str r3, [r1] 121 ret lr 122ENDPROC(debug_ll_addr) 123#endif 124 125#else 126 127ENTRY(printascii) 128 mov r1, r0 129 mov r0, #0x04 @ SYS_WRITE0 130 ARM( svc #0x123456 ) 131#ifdef CONFIG_CPU_V7M 132 THUMB( bkpt #0xab ) 133#else 134 THUMB( svc #0xab ) 135#endif 136 ret lr 137ENDPROC(printascii) 138 139ENTRY(printch) 140 adr r1, hexbuf_rel 141 ldr r2, [r1] 142 add r1, r1, r2 143 strb r0, [r1] 144 mov r0, #0x03 @ SYS_WRITEC 145 ARM( svc #0x123456 ) 146#ifdef CONFIG_CPU_V7M 147 THUMB( bkpt #0xab ) 148#else 149 THUMB( svc #0xab ) 150#endif 151 ret lr 152ENDPROC(printch) 153 154ENTRY(debug_ll_addr) 155 mov r2, #0 156 str r2, [r0] 157 str r2, [r1] 158 ret lr 159ENDPROC(debug_ll_addr) 160 161#endif 162