source: bootcd/isolinux/syslinux-6.03/com32/elflink/ldlinux/execute.c

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2004-2008 H. Peter Anvin - All Rights Reserved
 *
 *   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, Inc., 51 Franklin St, Fifth Floor,
 *   Boston MA 02110-1301, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <dprintf.h>

#include <com32.h>
#include <sys/exec.h>
#include <sys/io.h>
#include <sys/module.h>
#include "core.h"
#include "menu.h"
#include "fs.h"
#include "config.h"
#include "localboot.h"
#include "bios.h"

#include <syslinux/bootrm.h>
#include <syslinux/movebits.h>
#include <syslinux/config.h>
#include <syslinux/boot.h>

const struct image_types image_boot_types[] = {
    { "localboot", IMAGE_TYPE_LOCALBOOT },
    { "kernel", IMAGE_TYPE_KERNEL },
    { "linux", IMAGE_TYPE_LINUX },
    { "boot", IMAGE_TYPE_BOOT },
    { "bss", IMAGE_TYPE_BSS },
    { "pxe", IMAGE_TYPE_PXE },
    { "fdimage", IMAGE_TYPE_FDIMAGE },
    { "com32", IMAGE_TYPE_COM32 },
    { "config", IMAGE_TYPE_CONFIG },
    { NULL, 0 },
};

extern int create_args_and_load(char *);

__export void execute(const char *cmdline, uint32_t type, bool sysappend)
{
        const char *kernel, *args;
        const char *p;
        com32sys_t ireg;
        char *q, ch;

        memset(&ireg, 0, sizeof ireg);

        if (strlen(cmdline) >= MAX_CMDLINE_LEN) {
                printf("cmdline too long\n");
                return;
        }

        q = malloc(MAX_CMDLINE_LEN);
        if (!q) {
                printf("%s(): Fail to malloc a buffer to exec %s\n",
                        __func__, cmdline);
                return;
        }

        kernel = q;
        p = cmdline;
        while (*p && !my_isspace(*p))
                *q++ = *p++;
        *q++ = '\0';

        args = q;
        while (*p && my_isspace(*p))
                p++;

        do {
                *q++ = ch = *p++;
        } while (ch);

        if (sysappend) {
                /* If we've seen some args, insert a space */
                if (--q != args)
                        *q++ = ' ';

                do_sysappend(q);
        }

        dprintf("kernel is %s, args = %s  type = %d \n", kernel, args, type);

        if (kernel[0] == '.') {
                /* It might be a type specifier */
                const struct image_types *t;
                for (t = image_boot_types; t->name; t++) {
                        if (!strcmp(kernel + 1, t->name)) {
                                /*
                                 * Strip the type specifier, apply the
                                 * filename extension if COM32 and
                                 * retry.
                                 */
                                p = args;
                                if (t->type == IMAGE_TYPE_COM32) {
                                        p = apply_extension(p, ".c32");
                                        if (!p)
                                                return;
                                }

                                execute(p, t->type, sysappend);
                                return;
                        }
                }
        }

        if (type == IMAGE_TYPE_COM32) {
                /*
                 * We may be called with the console in an unknown
                 * state, so initialise it.
                 */
                ldlinux_console_init();

                /* new entry for elf format c32 */
                if (create_args_and_load((char *)cmdline))
                        printf("Failed to load COM32 file %s\n", kernel);

                /*
                 * The old COM32 module code would run the module then
                 * drop the user back at the command prompt,
                 * irrespective of how the COM32 module was loaded,
                 * e.g. from vesamenu.c32.
                 */
                unload_modules_since(LDLINUX);

                /* Restore the console */
                ldlinux_console_init();

                ldlinux_enter_command();
        } else if (type == IMAGE_TYPE_CONFIG) {
                char *argv[] = { LDLINUX, NULL, NULL };
                char *config;
                int rv;

                /* kernel contains the config file name */
                config = malloc(FILENAME_MAX);
                if (!config)
                        goto out;

                realpath(config, kernel, FILENAME_MAX);

                /* If we got anything on the command line, do a chdir */
                if (*args)
                        mangle_name(config_cwd, args);

                argv[1] = config;
                rv = start_ldlinux(2, argv);
                printf("Failed to exec %s: %s\n", LDLINUX, strerror(rv));
        } else if (type == IMAGE_TYPE_LOCALBOOT) {
                local_boot(strtoul(kernel, NULL, 0));
        } else if (type == IMAGE_TYPE_PXE || type == IMAGE_TYPE_BSS ||
                   type == IMAGE_TYPE_BOOT) {
                chainboot_file(kernel, type);
        } else {
                /* Need add one item for kernel load, as we don't use
                * the assembly runkernel.inc any more */
                new_linux_kernel((char *)kernel, (char *)args);
        }

out:
        free((void *)kernel);

        /* If this returns, something went bad; return to menu */
}