com32/modules/linux.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
   4  *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
   5  *
   6  *   Permission is hereby granted, free of charge, to any person
   7  *   obtaining a copy of this software and associated documentation
   8  *   files (the "Software"), to deal in the Software without
   9  *   restriction, including without limitation the rights to use,
  10  *   copy, modify, merge, publish, distribute, sublicense, and/or
  11  *   sell copies of the Software, and to permit persons to whom
  12  *   the Software is furnished to do so, subject to the following
  13  *   conditions:
  14  *
  15  *   The above copyright notice and this permission notice shall
  16  *   be included in all copies or substantial portions of the Software.
  17  *
  18  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  20  *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  22  *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  23  *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24  *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  25  *   OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  * ----------------------------------------------------------------------- */
  28
  29 /*
  30  * linux.c
  31  *
  32  * Sample module to load Linux kernels.  This module can also create
  33  * a file out of the DHCP return data if running under PXELINUX.
  34  *
  35  * If -dhcpinfo is specified, the DHCP info is written into the file
  36  * /dhcpinfo.dat in the initramfs.
  37  *
  38  * Usage: linux.c32 [-dhcpinfo] kernel arguments...
  39  */
  40
  41 #include <stdbool.h>
  42 #include <stdlib.h>
  43 #include <stdio.h>
  44 #include <string.h>
  45 #include <console.h>
  46 #include <syslinux/loadfile.h>
  47 #include <syslinux/linux.h>
  48 #include <syslinux/pxe.h>
  49
  50 const char *progname = "linux.c32";
  51
  52 /* Find the last instance of a particular command line argument
  53    (which should include the final =; do not use for boolean arguments) */
  54 static char *find_argument(char **argv, const char *argument)
  55 {
  56     int la = strlen(argument);
  57     char **arg;
  58     char *ptr = NULL;
  59
  60     for (arg = argv; *arg; arg++) {
  61         if (!memcmp(*arg, argument, la))
  62             ptr = *arg + la;
  63     }
  64
  65     return ptr;
  66 }
  67
  68 /* Search for a boolean argument; return its position, or 0 if not present */
  69 static int find_boolean(char **argv, const char *argument)
  70 {
  71     char **arg;
  72
  73     for (arg = argv; *arg; arg++) {
  74         if (!strcmp(*arg, argument))
  75             return (arg - argv) + 1;
  76     }
  77
  78     return 0;
  79 }
  80
  81 /* Stitch together the command line from a set of argv's */
  82 static char *make_cmdline(char **argv)
  83 {
  84     char **arg;
  85     size_t bytes;
  86     char *cmdline, *p;
  87
  88     bytes = 1;                  /* Just in case we have a zero-entry cmdline */
  89     for (arg = argv; *arg; arg++) {
  90         bytes += strlen(*arg) + 1;
  91     }
  92
  93     p = cmdline = malloc(bytes);
  94     if (!cmdline)
  95         return NULL;
  96
  97     for (arg = argv; *arg; arg++) {
  98         int len = strlen(*arg);
  99         memcpy(p, *arg, len);
 100         p[len] = ' ';
 101         p += len + 1;
 102     }
 103
 104     if (p > cmdline)
 105         p--;                    /* Remove the last space */
 106     *p = '\0';
 107
 108     return cmdline;
 109 }
 110
 111 int main(int argc, char *argv[])
 112 {
 113     const char *kernel_name;
 114     struct initramfs *initramfs;
 115     char *cmdline;
 116     char *boot_image;
 117     void *kernel_data;
 118     size_t kernel_len;
 119     bool opt_dhcpinfo = false;
 120     bool opt_quiet = false;
 121     void *dhcpdata;
 122     size_t dhcplen;
 123     char **argp, *arg, *p;
 124
 125     openconsole(&dev_null_r, &dev_stdcon_w);
 126
 127     (void)argc;
 128     argp = argv + 1;
 129
 130     while ((arg = *argp) && arg[0] == '-') {
 131         if (!strcmp("-dhcpinfo", arg)) {
 132             opt_dhcpinfo = true;
 133         } else {
 134             fprintf(stderr, "%s: unknown option: %s\n", progname, arg);
 135             return 1;
 136         }
 137         argp++;
 138     }
 139
 140     if (!arg) {
 141         fprintf(stderr, "%s: missing kernel name\n", progname);
 142         return 1;
 143     }
 144
 145     kernel_name = arg;
 146
 147     boot_image = malloc(strlen(kernel_name) + 12);
 148     if (!boot_image)
 149         goto bail;
 150     strcpy(boot_image, "BOOT_IMAGE=");
 151     strcpy(boot_image + 11, kernel_name);
 152     /* argp now points to the kernel name, and the command line follows.
 153        Overwrite the kernel name with the BOOT_IMAGE= argument, and thus
 154        we have the final argument. */
 155     *argp = boot_image;
 156
 157     if (find_boolean(argp, "quiet"))
 158         opt_quiet = true;
 159
 160     if (!opt_quiet)
 161         printf("Loading %s... ", kernel_name);
 162     if (loadfile(kernel_name, &kernel_data, &kernel_len)) {
 163         if (opt_quiet)
 164             printf("Loading %s ", kernel_name);
 165         printf("failed!\n");
 166         goto bail;
 167     }
 168     if (!opt_quiet)
 169         printf("ok\n");
 170
 171     cmdline = make_cmdline(argp);
 172     if (!cmdline)
 173         goto bail;
 174
 175     /* Initialize the initramfs chain */
 176     initramfs = initramfs_init();
 177     if (!initramfs)
 178         goto bail;
 179
 180     if ((arg = find_argument(argp, "initrd="))) {
 181         do {
 182             p = strchr(arg, ',');
 183             if (p)
 184                 *p = '\0';
 185
 186             if (!opt_quiet)
 187                 printf("Loading %s... ", arg);
 188             if (initramfs_load_archive(initramfs, arg)) {
 189                 if (opt_quiet)
 190                     printf("Loading %s ", kernel_name);
 191                 printf("failed!\n");
 192                 goto bail;
 193             }
 194             if (!opt_quiet)
 195                 printf("ok\n");
 196
 197             if (p)
 198                 *p++ = ',';
 199         } while ((arg = p));
 200     }
 201
 202     /* Append the DHCP info */
 203     if (opt_dhcpinfo &&
 204         !pxe_get_cached_info(PXENV_PACKET_TYPE_DHCP_ACK, &dhcpdata, &dhcplen)) {
 205         if (initramfs_add_file(initramfs, dhcpdata, dhcplen, dhcplen,
 206                                "/dhcpinfo.dat", 0, 0755))
 207             goto bail;
 208     }
 209
 210     /* This should not return... */
 211     syslinux_boot_linux(kernel_data, kernel_len, initramfs, cmdline);
 212
 213 bail:
 214     fprintf(stderr, "Kernel load failure (insufficient memory?)\n");
 215     return 1;
 216 }