kernel-ark/arch/powerpc/kernel/udbg.c

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/*
* polling mode stateless debugging stuff, originally for NS16550 Serial Ports
*
* c 2001 PPC 64 Team, IBM Corp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <stdarg.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/console.h>
#include <linux/init.h>
#include <asm/processor.h>
#include <asm/udbg.h>
void (*udbg_putc)(char c);
int (*udbg_getc)(void);
int (*udbg_getc_poll)(void);
/*
* Early debugging facilities. You can enable _one_ of these via .config,
* if you do so your kernel _will not boot_ on anything else. Be careful.
*/
void __init udbg_early_init(void)
{
#if defined(CONFIG_PPC_EARLY_DEBUG_LPAR)
/* For LPAR machines that have an HVC console on vterm 0 */
udbg_init_debug_lpar();
#elif defined(CONFIG_PPC_EARLY_DEBUG_G5)
/* For use on Apple G5 machines */
udbg_init_pmac_realmode();
#elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS)
/* RTAS panel debug */
udbg_init_rtas();
#elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE)
/* Maple real mode debug */
udbg_init_maple_realmode();
#elif defined(CONFIG_PPC_EARLY_DEBUG_ISERIES)
/* For iSeries - hit Ctrl-x Ctrl-x to see the output */
udbg_init_iseries();
#endif
}
/* udbg library, used by xmon et al */
void udbg_puts(const char *s)
{
if (udbg_putc) {
char c;
if (s && *s != '\0') {
while ((c = *s++) != '\0')
udbg_putc(c);
}
}
#if 0
else {
printk("%s", s);
}
#endif
}
int udbg_write(const char *s, int n)
{
int remain = n;
char c;
if (!udbg_putc)
return 0;
if (s && *s != '\0') {
while (((c = *s++) != '\0') && (remain-- > 0)) {
udbg_putc(c);
}
}
return n - remain;
}
int udbg_read(char *buf, int buflen)
{
char *p = buf;
int i, c;
if (!udbg_getc)
return 0;
for (i = 0; i < buflen; ++i) {
do {
c = udbg_getc();
if (c == -1 && i == 0)
return -1;
} while (c == 0x11 || c == 0x13);
if (c == 0 || c == -1)
break;
*p++ = c;
}
return i;
}
#define UDBG_BUFSIZE 256
void udbg_printf(const char *fmt, ...)
{
char buf[UDBG_BUFSIZE];
va_list args;
va_start(args, fmt);
vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
udbg_puts(buf);
va_end(args);
}
void __init udbg_progress(char *s, unsigned short hex)
{
udbg_puts(s);
udbg_puts("\n");
}
/*
* Early boot console based on udbg
*/
static void udbg_console_write(struct console *con, const char *s,
unsigned int n)
{
udbg_write(s, n);
}
static struct console udbg_console = {
.name = "udbg",
.write = udbg_console_write,
.flags = CON_PRINTBUFFER | CON_ENABLED,
.index = -1,
};
static int early_console_initialized;
void __init disable_early_printk(void)
{
if (!early_console_initialized)
return;
if (strstr(saved_command_line, "udbg-immortal")) {
printk(KERN_INFO "early console immortal !\n");
return;
}
unregister_console(&udbg_console);
early_console_initialized = 0;
}
/* called by setup_system */
void register_early_udbg_console(void)
{
if (early_console_initialized)
return;
early_console_initialized = 1;
register_console(&udbg_console);
}
#if 0 /* if you want to use this as a regular output console */
console_initcall(register_udbg_console);
#endif