arch/ppc/xmon/start_8xx.c

   1 /*
   2  * Copyright (C) 1996 Paul Mackerras.
   3  * Copyright (C) 2000 Dan Malek.
   4  * Quick hack of Paul's code to make XMON work on 8xx processors.  Lots
   5  * of assumptions, like the SMC1 is used, it has been initialized by the
   6  * loader at some point, and we can just stuff and suck bytes.
   7  * We rely upon the 8xx uart driver to support us, as the interface
   8  * changes between boot up and operational phases of the kernel.
   9  */
  10 #include <linux/string.h>
  11 #include <asm/machdep.h>
  12 #include <asm/io.h>
  13 #include <asm/page.h>
  14 #include <linux/kernel.h>
  15 #include <asm/8xx_immap.h>
  16 #include <asm/mpc8xx.h>
  17 #include <asm/cpm1.h>
  18
  19 extern void xmon_printf(const char *fmt, ...);
  20 extern int xmon_8xx_write(char *str, int nb);
  21 extern int xmon_8xx_read_poll(void);
  22 extern int xmon_8xx_read_char(void);
  23 void prom_drawhex(uint);
  24 void prom_drawstring(const char *str);
  25
  26 static int use_screen = 1; /* default */
  27
  28 #define TB_SPEED        25000000
  29
  30 static inline unsigned int readtb(void)
  31 {
  32         unsigned int ret;
  33
  34         asm volatile("mftb %0" : "=r" (ret) :);
  35         return ret;
  36 }
  37
  38 void buf_access(void)
  39 {
  40 }
  41
  42 void
  43 xmon_map_scc(void)
  44 {
  45
  46         cpmp = (cpm8xx_t *)&(((immap_t *)IMAP_ADDR)->im_cpm);
  47         use_screen = 0;
  48
  49         prom_drawstring("xmon uses serial port\n");
  50 }
  51
  52 static int scc_initialized = 0;
  53
  54 void xmon_init_scc(void);
  55
  56 int
  57 xmon_write(void *handle, void *ptr, int nb)
  58 {
  59         char *p = ptr;
  60         int i, c, ct;
  61
  62         if (!scc_initialized)
  63                 xmon_init_scc();
  64
  65         return(xmon_8xx_write(ptr, nb));
  66 }
  67
  68 int xmon_wants_key;
  69
  70 int
  71 xmon_read(void *handle, void *ptr, int nb)
  72 {
  73         char *p = ptr;
  74         int i;
  75
  76         if (!scc_initialized)
  77                 xmon_init_scc();
  78
  79         for (i = 0; i < nb; ++i) {
  80                 *p++ = xmon_8xx_read_char();
  81         }
  82         return i;
  83 }
  84
  85 int
  86 xmon_read_poll(void)
  87 {
  88         return(xmon_8xx_read_poll());
  89 }
  90
  91 void
  92 xmon_init_scc()
  93 {
  94         scc_initialized = 1;
  95 }
  96
  97 #if 0
  98 extern int (*prom_entry)(void *);
  99
 100 int
 101 xmon_exit(void)
 102 {
 103     struct prom_args {
 104         char *service;
 105     } args;
 106
 107     for (;;) {
 108         args.service = "exit";
 109         (*prom_entry)(&args);
 110     }
 111 }
 112 #endif
 113
 114 void *xmon_stdin;
 115 void *xmon_stdout;
 116 void *xmon_stderr;
 117
 118 void
 119 xmon_init(void)
 120 {
 121 }
 122
 123 int
 124 xmon_putc(int c, void *f)
 125 {
 126     char ch = c;
 127
 128     if (c == '\n')
 129         xmon_putc('\r', f);
 130     return xmon_write(f, &ch, 1) == 1? c: -1;
 131 }
 132
 133 int
 134 xmon_putchar(int c)
 135 {
 136     return xmon_putc(c, xmon_stdout);
 137 }
 138
 139 int
 140 xmon_fputs(char *str, void *f)
 141 {
 142     int n = strlen(str);
 143
 144     return xmon_write(f, str, n) == n? 0: -1;
 145 }
 146
 147 int
 148 xmon_readchar(void)
 149 {
 150     char ch;
 151
 152     for (;;) {
 153         switch (xmon_read(xmon_stdin, &ch, 1)) {
 154         case 1:
 155             return ch;
 156         case -1:
 157             xmon_printf("read(stdin) returned -1\r\n", 0, 0);
 158             return -1;
 159         }
 160     }
 161 }
 162
 163 static char line[256];
 164 static char *lineptr;
 165 static int lineleft;
 166
 167 #if 0
 168 int xmon_expect(const char *str, unsigned int timeout)
 169 {
 170         int c;
 171         unsigned int t0;
 172
 173         timeout *= TB_SPEED;
 174         t0 = readtb();
 175         do {
 176                 lineptr = line;
 177                 for (;;) {
 178                         c = xmon_read_poll();
 179                         if (c == -1) {
 180                                 if (readtb() - t0 > timeout)
 181                                         return 0;
 182                                 continue;
 183                         }
 184                         if (c == '\n')
 185                                 break;
 186                         if (c != '\r' && lineptr < &line[sizeof(line) - 1])
 187                                 *lineptr++ = c;
 188                 }
 189                 *lineptr = 0;
 190         } while (strstr(line, str) == NULL);
 191         return 1;
 192 }
 193 #endif
 194
 195 int
 196 xmon_getchar(void)
 197 {
 198     int c;
 199
 200     if (lineleft == 0) {
 201         lineptr = line;
 202         for (;;) {
 203             c = xmon_readchar();
 204             if (c == -1 || c == 4)
 205                 break;
 206             if (c == '\r' || c == '\n') {
 207                 *lineptr++ = '\n';
 208                 xmon_putchar('\n');
 209                 break;
 210             }
 211             switch (c) {
 212             case 0177:
 213             case '\b':
 214                 if (lineptr > line) {
 215                     xmon_putchar('\b');
 216                     xmon_putchar(' ');
 217                     xmon_putchar('\b');
 218                     --lineptr;
 219                 }
 220                 break;
 221             case 'U' & 0x1F:
 222                 while (lineptr > line) {
 223                     xmon_putchar('\b');
 224                     xmon_putchar(' ');
 225                     xmon_putchar('\b');
 226                     --lineptr;
 227                 }
 228                 break;
 229             default:
 230                 if (lineptr >= &line[sizeof(line) - 1])
 231                     xmon_putchar('\a');
 232                 else {
 233                     xmon_putchar(c);
 234                     *lineptr++ = c;
 235                 }
 236             }
 237         }
 238         lineleft = lineptr - line;
 239         lineptr = line;
 240     }
 241     if (lineleft == 0)
 242         return -1;
 243     --lineleft;
 244     return *lineptr++;
 245 }
 246
 247 char *
 248 xmon_fgets(char *str, int nb, void *f)
 249 {
 250     char *p;
 251     int c;
 252
 253     for (p = str; p < str + nb - 1; ) {
 254         c = xmon_getchar();
 255         if (c == -1) {
 256             if (p == str)
 257                 return 0;
 258             break;
 259         }
 260         *p++ = c;
 261         if (c == '\n')
 262             break;
 263     }
 264     *p = 0;
 265     return str;
 266 }
 267
 268 void
 269 prom_drawhex(uint val)
 270 {
 271         unsigned char buf[10];
 272
 273         int i;
 274         for (i = 7;  i >= 0;  i--)
 275         {
 276                 buf[i] = "0123456789abcdef"[val & 0x0f];
 277                 val >>= 4;
 278         }
 279         buf[8] = '\0';
 280         xmon_fputs(buf, xmon_stdout);
 281 }
 282
 283 void
 284 prom_drawstring(const char *str)
 285 {
 286         xmon_fputs(str, xmon_stdout);
 287 }