LXR linux/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
  20void (*udbg_putc)(char c);
  21void (*udbg_flush)(void);
  22int (*udbg_getc)(void);
  23int (*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 */
  29void __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 */
  71void 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
  91int 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
 111int 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
 135void 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
 146void __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 */
 155static void udbg_console_write(struct console *con, const char *s,
 156                unsigned int n)
 157{
 158        udbg_write(s, n);
 159}
 160
 161static 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
 168static 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 */
 174void __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 */
 191console_initcall(register_udbg_console);
 192#endif
 193