kernel/arch/powerpc/xmon/nonstdio.c

   1 /*
   2  * Copyright (C) 1996-2005 Paul Mackerras.
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  */
   9 #include <linux/string.h>
  10 #include <asm/udbg.h>
  11 #include <asm/time.h>
  12 #include "nonstdio.h"
  13
  14
  15 static int xmon_write(const void *ptr, int nb)
  16 {
  17         return udbg_write(ptr, nb);
  18 }
  19
  20 static int xmon_readchar(void)
  21 {
  22         if (udbg_getc)
  23                 return udbg_getc();
  24         return -1;
  25 }
  26
  27 int xmon_putchar(int c)
  28 {
  29         char ch = c;
  30
  31         if (c == '\n')
  32                 xmon_putchar('\r');
  33         return xmon_write(&ch, 1) == 1? c: -1;
  34 }
  35
  36 static char line[256];
  37 static char *lineptr;
  38 static int lineleft;
  39
  40 static int xmon_getchar(void)
  41 {
  42         int c;
  43
  44         if (lineleft == 0) {
  45                 lineptr = line;
  46                 for (;;) {
  47                         c = xmon_readchar();
  48                         if (c == -1 || c == 4)
  49                                 break;
  50                         if (c == '\r' || c == '\n') {
  51                                 *lineptr++ = '\n';
  52                                 xmon_putchar('\n');
  53                                 break;
  54                         }
  55                         switch (c) {
  56                         case 0177:
  57                         case '\b':
  58                                 if (lineptr > line) {
  59                                         xmon_putchar('\b');
  60                                         xmon_putchar(' ');
  61                                         xmon_putchar('\b');
  62                                         --lineptr;
  63                                 }
  64                                 break;
  65                         case 'U' & 0x1F:
  66                                 while (lineptr > line) {
  67                                         xmon_putchar('\b');
  68                                         xmon_putchar(' ');
  69                                         xmon_putchar('\b');
  70                                         --lineptr;
  71                                 }
  72                                 break;
  73                         default:
  74                                 if (lineptr >= &line[sizeof(line) - 1])
  75                                         xmon_putchar('\a');
  76                                 else {
  77                                         xmon_putchar(c);
  78                                         *lineptr++ = c;
  79                                 }
  80                         }
  81                 }
  82                 lineleft = lineptr - line;
  83                 lineptr = line;
  84         }
  85         if (lineleft == 0)
  86                 return -1;
  87         --lineleft;
  88         return *lineptr++;
  89 }
  90
  91 char *xmon_gets(char *str, int nb)
  92 {
  93         char *p;
  94         int c;
  95
  96         for (p = str; p < str + nb - 1; ) {
  97                 c = xmon_getchar();
  98                 if (c == -1) {
  99                         if (p == str)
 100                                 return NULL;
 101                         break;
 102                 }
 103                 *p++ = c;
 104                 if (c == '\n')
 105                         break;
 106         }
 107         *p = 0;
 108         return str;
 109 }
 110
 111 void xmon_printf(const char *format, ...)
 112 {
 113         va_list args;
 114         static char xmon_outbuf[1024];
 115         int rc, n;
 116
 117         va_start(args, format);
 118         n = vsnprintf(xmon_outbuf, sizeof(xmon_outbuf), format, args);
 119         va_end(args);
 120
 121         rc = xmon_write(xmon_outbuf, n);
 122
 123         if (n && rc == 0) {
 124                 /* No udbg hooks, fallback to printk() - dangerous */
 125                 printk("%s", xmon_outbuf);
 126         }
 127 }
 128
 129 void xmon_puts(const char *str)
 130 {
 131         xmon_write(str, strlen(str));
 132 }