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