arch/arm/kernel/debug.S

   1 /*
   2  *  linux/arch/arm/kernel/debug.S
   3  *
   4  *  Copyright (C) 1994-1999 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  32-bit debugging code
  11  */
  12 #include <linux/linkage.h>
  13 #include <asm/assembler.h>
  14
  15                 .text
  16
  17 /*
  18  * Some debugging routines (useful if you've got MM problems and
  19  * printk isn't working).  For DEBUGGING ONLY!!!  Do not leave
  20  * references to these in a production kernel!
  21  */
  22
  23 #if !defined(CONFIG_DEBUG_SEMIHOSTING)
  24 #include CONFIG_DEBUG_LL_INCLUDE
  25 #endif
  26
  27 #ifdef CONFIG_MMU
  28                 .macro  addruart_current, rx, tmp1, tmp2
  29                 addruart        \tmp1, \tmp2, \rx
  30                 mrc             p15, 0, \rx, c1, c0
  31                 tst             \rx, #1
  32                 moveq           \rx, \tmp1
  33                 movne           \rx, \tmp2
  34                 .endm
  35
  36 #else /* !CONFIG_MMU */
  37                 .macro  addruart_current, rx, tmp1, tmp2
  38                 addruart        \rx, \tmp1
  39                 .endm
  40
  41 #endif /* CONFIG_MMU */
  42
  43 /*
  44  * Useful debugging routines
  45  */
  46 ENTRY(printhex8)
  47                 mov     r1, #8
  48                 b       printhex
  49 ENDPROC(printhex8)
  50
  51 ENTRY(printhex4)
  52                 mov     r1, #4
  53                 b       printhex
  54 ENDPROC(printhex4)
  55
  56 ENTRY(printhex2)
  57                 mov     r1, #2
  58 printhex:       adr     r2, hexbuf
  59                 add     r3, r2, r1
  60                 mov     r1, #0
  61                 strb    r1, [r3]
  62 1:              and     r1, r0, #15
  63                 mov     r0, r0, lsr #4
  64                 cmp     r1, #10
  65                 addlt   r1, r1, #'0'
  66                 addge   r1, r1, #'a' - 10
  67                 strb    r1, [r3, #-1]!
  68                 teq     r3, r2
  69                 bne     1b
  70                 mov     r0, r2
  71                 b       printascii
  72 ENDPROC(printhex2)
  73
  74 hexbuf:         .space 16
  75
  76                 .ltorg
  77
  78 #ifndef CONFIG_DEBUG_SEMIHOSTING
  79
  80 ENTRY(printascii)
  81                 addruart_current r3, r1, r2
  82                 b       2f
  83 1:              waituart r2, r3
  84                 senduart r1, r3
  85                 busyuart r2, r3
  86                 teq     r1, #'\n'
  87                 moveq   r1, #'\r'
  88                 beq     1b
  89 2:              teq     r0, #0
  90                 ldrneb  r1, [r0], #1
  91                 teqne   r1, #0
  92                 bne     1b
  93                 mov     pc, lr
  94 ENDPROC(printascii)
  95
  96 ENTRY(printch)
  97                 addruart_current r3, r1, r2
  98                 mov     r1, r0
  99                 mov     r0, #0
 100                 b       1b
 101 ENDPROC(printch)
 102
 103 #ifdef CONFIG_MMU
 104 ENTRY(debug_ll_addr)
 105                 addruart r2, r3, ip
 106                 str     r2, [r0]
 107                 str     r3, [r1]
 108                 mov     pc, lr
 109 ENDPROC(debug_ll_addr)
 110 #endif
 111
 112 #else
 113
 114 ENTRY(printascii)
 115                 mov     r1, r0
 116                 mov     r0, #0x04               @ SYS_WRITE0
 117         ARM(    svc     #0x123456       )
 118         THUMB(  svc     #0xab           )
 119                 mov     pc, lr
 120 ENDPROC(printascii)
 121
 122 ENTRY(printch)
 123                 adr     r1, hexbuf
 124                 strb    r0, [r1]
 125                 mov     r0, #0x03               @ SYS_WRITEC
 126         ARM(    svc     #0x123456       )
 127         THUMB(  svc     #0xab           )
 128                 mov     pc, lr
 129 ENDPROC(printch)
 130
 131 ENTRY(debug_ll_addr)
 132                 mov     r2, #0
 133                 str     r2, [r0]
 134                 str     r2, [r1]
 135                 mov     pc, lr
 136 ENDPROC(debug_ll_addr)
 137
 138 #endif