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_LPAR_HVSI)
  35         /* For LPAR machines that have an HVSI console on vterm 0 */
  36         udbg_init_debug_lpar_hvsi();
  37 #elif defined(CONFIG_PPC_EARLY_DEBUG_G5)
  38         /* For use on Apple G5 machines */
  39         udbg_init_pmac_realmode();
  40 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_PANEL)
  41         /* RTAS panel debug */
  42         udbg_init_rtas_panel();
  43 #elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE)
  44         /* RTAS console debug */
  45         udbg_init_rtas_console();
  46 #elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE)
  47         /* Maple real mode debug */
  48         udbg_init_maple_realmode();
  49 #elif defined(CONFIG_PPC_EARLY_DEBUG_ISERIES)
  50         /* For iSeries - hit Ctrl-x Ctrl-x to see the output */
  51         udbg_init_iseries();
  52 #elif defined(CONFIG_PPC_EARLY_DEBUG_BEAT)
  53         udbg_init_debug_beat();
  54 #elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
  55         udbg_init_pas_realmode();
  56 #elif defined(CONFIG_BOOTX_TEXT)
  57         udbg_init_btext();
  58 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
  59         /* PPC44x debug */
  60         udbg_init_44x_as1();
  61 #elif defined(CONFIG_PPC_EARLY_DEBUG_40x)
  62         /* PPC40x debug */
  63         udbg_init_40x_realmode();
  64 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
  65         udbg_init_cpm();
  66 #elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
  67         udbg_init_usbgecko();
  68 #elif defined(CONFIG_PPC_EARLY_DEBUG_WSP)
  69         udbg_init_wsp();
  70 #endif
  71
  72 #ifdef CONFIG_PPC_EARLY_DEBUG
  73         console_loglevel = 10;
  74
  75         register_early_udbg_console();
  76 #endif
  77 }
  78
  79 /* udbg library, used by xmon et al */
  80 void udbg_puts(const char *s)
  81 {
  82         if (udbg_putc) {
  83                 char c;
  84
  85                 if (s && *s != '\0') {
  86                         while ((c = *s++) != '\0')
  87                                 udbg_putc(c);
  88                 }
  89
  90                 if (udbg_flush)
  91                         udbg_flush();
  92         }
  93 #if 0
  94         else {
  95                 printk("%s", s);
  96         }
  97 #endif
  98 }
  99
 100 int udbg_write(const char *s, int n)
 101 {
 102         int remain = n;
 103         char c;
 104
 105         if (!udbg_putc)
 106                 return 0;
 107
 108         if (s && *s != '\0') {
 109                 while (((c = *s++) != '\0') && (remain-- > 0)) {
 110                         udbg_putc(c);
 111                 }
 112         }
 113
 114         if (udbg_flush)
 115                 udbg_flush();
 116
 117         return n - remain;
 118 }
 119
 120 int udbg_read(char *buf, int buflen)
 121 {
 122         char *p = buf;
 123         int i, c;
 124
 125         if (!udbg_getc)
 126                 return 0;
 127
 128         for (i = 0; i < buflen; ++i) {
 129                 do {
 130                         c = udbg_getc();
 131                         if (c == -1 && i == 0)
 132                                 return -1;
 133
 134                 } while (c == 0x11 || c == 0x13);
 135                 if (c == 0 || c == -1)
 136                         break;
 137                 *p++ = c;
 138         }
 139
 140         return i;
 141 }
 142
 143 #define UDBG_BUFSIZE 256
 144 void udbg_printf(const char *fmt, ...)
 145 {
 146         char buf[UDBG_BUFSIZE];
 147         va_list args;
 148
 149         va_start(args, fmt);
 150         vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
 151         udbg_puts(buf);
 152         va_end(args);
 153 }
 154
 155 void __init udbg_progress(char *s, unsigned short hex)
 156 {
 157         udbg_puts(s);
 158         udbg_puts("\n");
 159 }
 160
 161 /*
 162  * Early boot console based on udbg
 163  */
 164 static void udbg_console_write(struct console *con, const char *s,
 165                 unsigned int n)
 166 {
 167         udbg_write(s, n);
 168 }
 169
 170 static struct console udbg_console = {
 171         .name   = "udbg",
 172         .write  = udbg_console_write,
 173         .flags  = CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
 174         .index  = 0,
 175 };
 176
 177 static int early_console_initialized;
 178
 179 /*
 180  * Called by setup_system after ppc_md->probe and ppc_md->early_init.
 181  * Call it again after setting udbg_putc in ppc_md->setup_arch.
 182  */
 183 void __init register_early_udbg_console(void)
 184 {
 185         if (early_console_initialized)
 186                 return;
 187
 188         if (!udbg_putc)
 189                 return;
 190
 191         if (strstr(boot_command_line, "udbg-immortal")) {
 192                 printk(KERN_INFO "early console immortal !\n");
 193                 udbg_console.flags &= ~CON_BOOT;
 194         }
 195         early_console_initialized = 1;
 196         register_console(&udbg_console);
 197 }
 198
 199 #if 0   /* if you want to use this as a regular output console */
 200 console_initcall(register_udbg_console);
 201 #endif