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/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);
void (*udbg_flush)(void);
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_LPAR_HVSI)
    /* For LPAR machines that have an HVSI console on vterm 0 */
    udbg_init_debug_lpar_hvsi();
#elif defined(CONFIG_PPC_EARLY_DEBUG_G5)
    /* For use on Apple G5 machines */
    udbg_init_pmac_realmode();
#elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_PANEL)
    /* RTAS panel debug */
    udbg_init_rtas_panel();
#elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE)
    /* RTAS console debug */
    udbg_init_rtas_console();
#elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE)
    /* Maple real mode debug */
    udbg_init_maple_realmode();
#elif defined(CONFIG_PPC_EARLY_DEBUG_BEAT)
    udbg_init_debug_beat();
#elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
    udbg_init_pas_realmode();
#elif defined(CONFIG_BOOTX_TEXT)
    udbg_init_btext();
#elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
    /* PPC44x debug */
    udbg_init_44x_as1();
#elif defined(CONFIG_PPC_EARLY_DEBUG_40x)
    /* PPC40x debug */
    udbg_init_40x_realmode();
#elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
    udbg_init_cpm();
#elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
    udbg_init_usbgecko();
#elif defined(CONFIG_PPC_EARLY_DEBUG_WSP)
    udbg_init_wsp();
#elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
    udbg_init_ehv_bc();
#elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC)
    udbg_init_ps3gelic();
#elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW)
    udbg_init_debug_opal_raw();
#elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI)
    udbg_init_debug_opal_hvsi();
#endif

#ifdef CONFIG_PPC_EARLY_DEBUG
    console_loglevel = 10;

    register_early_udbg_console();
#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 (udbg_flush)
            udbg_flush();
    }
#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);
        }
    }

    if (udbg_flush)
        udbg_flush();

    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 | CON_BOOT | CON_ANYTIME,
    .index  = 0,
};

static int early_console_initialized;

/*
 * Called by setup_system after ppc_md->probe and ppc_md->early_init.
 * Call it again after setting udbg_putc in ppc_md->setup_arch.
 */
void __init register_early_udbg_console(void)
{
    if (early_console_initialized)
        return;

    if (!udbg_putc)
        return;

    if (strstr(boot_command_line, "udbg-immortal")) {
        printk(KERN_INFO "early console immortal !\n");
        udbg_console.flags &= ~CON_BOOT;
    }
    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