arch/powerpc/kernel/udbg.c

   1 /*
   2  * polling mode stateless debugging stuff, originally for NS16550 Serial Ports
   3  *
   4  * c 2001 PPC 64 Team, IBM Corp
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <stdarg.h>
  13 #include <linux/types.h>
  14 #include <linux/sched.h>
  15 #include <linux/console.h>
  16 #include <linux/init.h>
  17 #include <asm/processor.h>
  18 #include <asm/udbg.h>
  19
  20 void (*udbg_putc)(char c);
  21 void (*udbg_flush)(void);
  22 int (*udbg_getc)(void);
  23 int (*udbg_getc_poll)(void);
  24
  25 /*
  26  * Early debugging facilities. You can enable _one_ of these via .config,
  27  * if you do so your kernel _will not boot_ on anything else. Be careful.
  28  */
  29 void __init udbg_early_init(void)
  30 {
  31 #if defined(CONFIG_PPC_EARLY_DEBUG_LPAR)
  32         /* For LPAR machines that have an HVC console on vterm 0 */
  33         udbg_init_debug_lpar();
  34 #elif defined(CONFIG_PPC_EARLY_DEBUG_G5)
  35         /* For use on Apple G5 machines */
  36         udbg_init_pmac_realmode();
  37 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_PANEL)
  38         /* RTAS panel debug */
  39         udbg_init_rtas_panel();
  40 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE)
  41         /* RTAS console debug */
  42         udbg_init_rtas_console();
  43 #elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE)
  44         /* Maple real mode debug */
  45         udbg_init_maple_realmode();
  46 #elif defined(CONFIG_PPC_EARLY_DEBUG_ISERIES)
  47         /* For iSeries - hit Ctrl-x Ctrl-x to see the output */
  48         udbg_init_iseries();
  49 #elif defined(CONFIG_PPC_EARLY_DEBUG_BEAT)
  50         udbg_init_debug_beat();
  51 #elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
  52         udbg_init_pas_realmode();
  53 #elif defined(CONFIG_BOOTX_TEXT)
  54         udbg_init_btext();
  55 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
  56         /* PPC44x debug */
  57         udbg_init_44x_as1();
  58 #elif defined(CONFIG_PPC_EARLY_DEBUG_40x)
  59         /* PPC40x debug */
  60         udbg_init_40x_realmode();
  61 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
  62         udbg_init_cpm();
  63 #endif
  64
  65 #ifdef CONFIG_PPC_EARLY_DEBUG
  66         console_loglevel = 10;
  67 #endif
  68 }
  69
  70 /* udbg library, used by xmon et al */
  71 void udbg_puts(const char *s)
  72 {
  73         if (udbg_putc) {
  74                 char c;
  75
  76                 if (s && *s != '\0') {
  77                         while ((c = *s++) != '\0')
  78                                 udbg_putc(c);
  79                 }
  80
  81                 if (udbg_flush)
  82                         udbg_flush();
  83         }
  84 #if 0
  85         else {
  86                 printk("%s", s);
  87         }
  88 #endif
  89 }
  90
  91 int udbg_write(const char *s, int n)
  92 {
  93         int remain = n;
  94         char c;
  95
  96         if (!udbg_putc)
  97                 return 0;
  98
  99         if (s && *s != '\0') {
 100                 while (((c = *s++) != '\0') && (remain-- > 0)) {
 101                         udbg_putc(c);
 102                 }
 103         }
 104
 105         if (udbg_flush)
 106                 udbg_flush();
 107
 108         return n - remain;
 109 }
 110
 111 int udbg_read(char *buf, int buflen)
 112 {
 113         char *p = buf;
 114         int i, c;
 115
 116         if (!udbg_getc)
 117                 return 0;
 118
 119         for (i = 0; i < buflen; ++i) {
 120                 do {
 121                         c = udbg_getc();
 122                         if (c == -1 && i == 0)
 123                                 return -1;
 124
 125                 } while (c == 0x11 || c == 0x13);
 126                 if (c == 0 || c == -1)
 127                         break;
 128                 *p++ = c;
 129         }
 130
 131         return i;
 132 }
 133
 134 #define UDBG_BUFSIZE 256
 135 void udbg_printf(const char *fmt, ...)
 136 {
 137         char buf[UDBG_BUFSIZE];
 138         va_list args;
 139
 140         va_start(args, fmt);
 141         vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
 142         udbg_puts(buf);
 143         va_end(args);
 144 }
 145
 146 void __init udbg_progress(char *s, unsigned short hex)
 147 {
 148         udbg_puts(s);
 149         udbg_puts("\n");
 150 }
 151
 152 /*
 153  * Early boot console based on udbg
 154  */
 155 static void udbg_console_write(struct console *con, const char *s,
 156                 unsigned int n)
 157 {
 158         udbg_write(s, n);
 159 }
 160
 161 static struct console udbg_console = {
 162         .name   = "udbg",
 163         .write  = udbg_console_write,
 164         .flags  = CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
 165         .index  = 0,
 166 };
 167
 168 static int early_console_initialized;
 169
 170 /*
 171  * Called by setup_system after ppc_md->probe and ppc_md->early_init.
 172  * Call it again after setting udbg_putc in ppc_md->setup_arch.
 173  */
 174 void __init register_early_udbg_console(void)
 175 {
 176         if (early_console_initialized)
 177                 return;
 178
 179         if (!udbg_putc)
 180                 return;
 181
 182         if (strstr(boot_command_line, "udbg-immortal")) {
 183                 printk(KERN_INFO "early console immortal !\n");
 184                 udbg_console.flags &= ~CON_BOOT;
 185         }
 186         early_console_initialized = 1;
 187         register_console(&udbg_console);
 188 }
 189
 190 #if 0   /* if you want to use this as a regular output console */
 191 console_initcall(register_udbg_console);
 192 #endif