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 #elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
  71         udbg_init_ehv_bc();
  72 #endif
  73
  74 #ifdef CONFIG_PPC_EARLY_DEBUG
  75         console_loglevel = 10;
  76
  77         register_early_udbg_console();
  78 #endif
  79 }
  80
  81 /* udbg library, used by xmon et al */
  82 void udbg_puts(const char *s)
  83 {
  84         if (udbg_putc) {
  85                 char c;
  86
  87                 if (s && *s != '\0') {
  88                         while ((c = *s++) != '\0')
  89                                 udbg_putc(c);
  90                 }
  91
  92                 if (udbg_flush)
  93                         udbg_flush();
  94         }
  95 #if 0
  96         else {
  97                 printk("%s", s);
  98         }
  99 #endif
 100 }
 101
 102 int udbg_write(const char *s, int n)
 103 {
 104         int remain = n;
 105         char c;
 106
 107         if (!udbg_putc)
 108                 return 0;
 109
 110         if (s && *s != '\0') {
 111                 while (((c = *s++) != '\0') && (remain-- > 0)) {
 112                         udbg_putc(c);
 113                 }
 114         }
 115
 116         if (udbg_flush)
 117                 udbg_flush();
 118
 119         return n - remain;
 120 }
 121
 122 int udbg_read(char *buf, int buflen)
 123 {
 124         char *p = buf;
 125         int i, c;
 126
 127         if (!udbg_getc)
 128                 return 0;
 129
 130         for (i = 0; i < buflen; ++i) {
 131                 do {
 132                         c = udbg_getc();
 133                         if (c == -1 && i == 0)
 134                                 return -1;
 135
 136                 } while (c == 0x11 || c == 0x13);
 137                 if (c == 0 || c == -1)
 138                         break;
 139                 *p++ = c;
 140         }
 141
 142         return i;
 143 }
 144
 145 #define UDBG_BUFSIZE 256
 146 void udbg_printf(const char *fmt, ...)
 147 {
 148         char buf[UDBG_BUFSIZE];
 149         va_list args;
 150
 151         va_start(args, fmt);
 152         vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
 153         udbg_puts(buf);
 154         va_end(args);
 155 }
 156
 157 void __init udbg_progress(char *s, unsigned short hex)
 158 {
 159         udbg_puts(s);
 160         udbg_puts("\n");
 161 }
 162
 163 /*
 164  * Early boot console based on udbg
 165  */
 166 static void udbg_console_write(struct console *con, const char *s,
 167                 unsigned int n)
 168 {
 169         udbg_write(s, n);
 170 }
 171
 172 static struct console udbg_console = {
 173         .name   = "udbg",
 174         .write  = udbg_console_write,
 175         .flags  = CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
 176         .index  = 0,
 177 };
 178
 179 static int early_console_initialized;
 180
 181 /*
 182  * Called by setup_system after ppc_md->probe and ppc_md->early_init.
 183  * Call it again after setting udbg_putc in ppc_md->setup_arch.
 184  */
 185 void __init register_early_udbg_console(void)
 186 {
 187         if (early_console_initialized)
 188                 return;
 189
 190         if (!udbg_putc)
 191                 return;
 192
 193         if (strstr(boot_command_line, "udbg-immortal")) {
 194                 printk(KERN_INFO "early console immortal !\n");
 195                 udbg_console.flags &= ~CON_BOOT;
 196         }
 197         early_console_initialized = 1;
 198         register_console(&udbg_console);
 199 }
 200
 201 #if 0   /* if you want to use this as a regular output console */
 202 console_initcall(register_udbg_console);
 203 #endif