X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;ds=sidebyside;f=helper%2Fext2initrd.c;fp=helper%2Fext2initrd.c;h=c9812322b22a0d733299f6acfbc3dad36a4eb11b;hb=89e336ee166be538e376d288fb2b3fbbffd66d4c;hp=0000000000000000000000000000000000000000;hpb=53bf430e26f4a53837bd38b58a427079caab3d4b;p=febootstrap.git

diff --git a/helper/ext2initrd.c b/helper/ext2initrd.c
new file mode 100644
index 0000000..c981232
--- /dev/null
+++ b/helper/ext2initrd.c
@@ -0,0 +1,263 @@
+/* febootstrap-supermin-helper reimplementation in C.
+ * Copyright (C) 2009-2010 Red Hat Inc.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* ext2 requires a small initrd in order to boot.  This builds it. */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <errno.h>
+
+#include "error.h"
+#include "full-write.h"
+#include "xalloc.h"
+#include "xvasprintf.h"
+
+#include "helper.h"
+#include "ext2internal.h"
+
+static void read_module_deps (const char *modpath);
+static void free_module_deps (void);
+static const char *get_module_dep (const char *);
+
+/* The init binary. */
+extern char _binary_init_start, _binary_init_end, _binary_init_size;
+
+/* The list of modules (wildcards) we consider for inclusion in the
+ * mini initrd.  Only what is needed in order to find a device with an
+ * ext2 filesystem on it.
+ */
+static const char *kmods[] = {
+  "ext2.ko",
+  "virtio*.ko",
+  "ide*.ko",
+  "libata*.ko",
+  "piix*.ko",
+  "scsi_transport_spi.ko",
+  "scsi_mod.ko",
+  "sd_mod.ko",
+  "sym53c8xx.ko",
+  "ata_piix.ko",
+  "sr_mod.ko",
+  "mbcache.ko",
+  "crc*.ko",
+  "libcrc*.ko",
+  NULL
+};
+
+void
+ext2_make_initrd (const char *modpath, const char *initrd)
+{
+  char dir[] = "/tmp/ext2initrdXXXXXX";
+  if (mkdtemp (dir) == NULL)
+    error (EXIT_FAILURE, errno, "mkdtemp");
+
+  char *cmd;
+  int r;
+
+  /* Copy kernel modules into tmpdir. */
+  size_t n = strlen (modpath) + strlen (dir) + 64;
+  size_t i;
+  for (i = 0; kmods[i] != NULL; ++i)
+    n += strlen (kmods[i]) + 16;
+  cmd = malloc (n);
+  sprintf (cmd, "find '%s' ", modpath);
+  for (i = 0; kmods[i] != NULL; ++i) {
+    if (i > 0) strcat (cmd, "-o ");
+    strcat (cmd, "-name '");
+    strcat (cmd, kmods[i]);
+    strcat (cmd, "' ");
+  }
+  strcat (cmd, "| xargs cp -t ");
+  strcat (cmd, dir);
+  if (verbose >= 2) fprintf (stderr, "%s\n", cmd);
+  r = system (cmd);
+  if (r == -1 || WEXITSTATUS (r) != 0)
+    error (EXIT_FAILURE, 0, "ext2_make_initrd: copy kmods failed");
+  free (cmd);
+
+  /* The above command effectively gives us the final list of modules.
+   * Calculate dependencies from modpath/modules.dep and write that
+   * into the output.
+   */
+  read_module_deps (modpath);
+
+  cmd = xasprintf ("tsort > %s/modules", dir);
+  if (verbose >= 2) fprintf (stderr, "%s\n", cmd);
+  FILE *pp = popen (cmd, "w");
+  if (pp == NULL)
+    error (EXIT_FAILURE, errno, "tsort: failed to create modules list");
+
+  DIR *dr = opendir (dir);
+  if (dr == NULL)
+    error (EXIT_FAILURE, errno, "opendir: %s", dir);
+
+  struct dirent *d;
+  while ((errno = 0, d = readdir (dr)) != NULL) {
+    size_t n = strlen (d->d_name);
+    if (n >= 3 &&
+        d->d_name[n-3] == '.' &&
+        d->d_name[n-2] == 'k' &&
+        d->d_name[n-1] == 'o') {
+      const char *dep = get_module_dep (d->d_name);
+      if (dep)
+        /* Reversed so that tsort will print the final list in the
+         * order that it has to be loaded.
+         */
+        fprintf (pp, "%s %s\n", dep, d->d_name);
+      else
+        /* No dependencies, just make it depend on itself so that
+         * tsort prints it.
+         */
+        fprintf (pp, "%s %s\n", d->d_name, d->d_name);
+    }
+  }
+  if (errno)
+    error (EXIT_FAILURE, errno, "readdir: %s", dir);
+
+  if (closedir (dr) == -1)
+    error (EXIT_FAILURE, errno, "closedir: %s", dir);
+
+  if (pclose (pp) == -1)
+    error (EXIT_FAILURE, errno, "pclose: %s", cmd);
+
+  free (cmd);
+  free_module_deps ();
+
+  /* Copy in insmod static binary. */
+  cmd = xasprintf ("cp /sbin/insmod.static %s", dir);
+  if (verbose >= 2) fprintf (stderr, "%s\n", cmd);
+  r = system (cmd);
+  if (r == -1 || WEXITSTATUS (r) != 0)
+    error (EXIT_FAILURE, 0,
+           "ext2_make_initrd: copy /sbin/insmod.static failed");
+  free (cmd);
+
+  /* Copy in the init program, linked into this program as a data blob. */
+  char *init = xasprintf ("%s/init", dir);
+  int fd = open (init, O_WRONLY|O_TRUNC|O_CREAT|O_NOCTTY, 0755);
+  if (fd == -1)
+    error (EXIT_FAILURE, errno, "open: %s", init);
+
+  n = (size_t) &_binary_init_size;
+  if (full_write (fd, &_binary_init_start, n) != n)
+    error (EXIT_FAILURE, errno, "write: %s", init);
+
+  if (close (fd) == -1)
+    error (EXIT_FAILURE, errno, "close: %s", init);
+
+  free (init);
+
+  /* Build the cpio file. */
+  cmd = xasprintf ("(cd %s && (echo . ; ls -1)"
+                   " | cpio --quiet -o -H newc) > '%s'",
+                   dir, initrd);
+  if (verbose >= 2) fprintf (stderr, "%s\n", cmd);
+  r = system (cmd);
+  if (r == -1 || WEXITSTATUS (r) != 0)
+    error (EXIT_FAILURE, 0, "ext2_make_initrd: cpio failed");
+  free (cmd);
+
+  /* Construction of 'dir' above ensures this is safe. */
+  cmd = xasprintf ("rm -rf %s", dir);
+  if (verbose >= 2) fprintf (stderr, "%s\n", cmd);
+  system (cmd);
+  free (cmd);
+}
+
+/* Module dependencies. */
+struct moddep {
+  struct moddep *next;
+  char *name;
+  char *dep;
+};
+struct moddep *moddeps = NULL;
+
+static void add_module_dep (const char *name, const char *dep);
+
+static void
+free_module_deps (void)
+{
+  /* Short-lived program, don't bother to free it. */
+  moddeps = NULL;
+}
+
+/* Read modules.dep into internal structure. */
+static void
+read_module_deps (const char *modpath)
+{
+  free_module_deps ();
+
+  char *filename = xasprintf ("%s/modules.dep", modpath);
+  FILE *fp = fopen (filename, "r");
+  if (fp == NULL)
+    error (EXIT_FAILURE, errno, "open: %s", modpath);
+
+  char *line = NULL;
+  size_t llen = 0;
+  ssize_t len;
+  while ((len = getline (&line, &llen, fp)) != -1) {
+    if (len > 0 && line[len-1] == '\n')
+      line[--len] = '\0';
+
+    char *name = strtok (line, ": ");
+    if (!name) continue;
+
+    /* Only want the module basename, but keep the ".ko" extension. */
+    char *p = strrchr (name, '/');
+    if (p) name = p+1;
+
+    char *dep;
+    while ((dep = strtok (NULL, " ")) != NULL) {
+      p = strrchr (dep, '/');
+      if (p) dep = p+1;
+
+      add_module_dep (name, dep);
+    }
+  }
+
+  free (line);
+  fclose (fp);
+}
+
+/* Module 'name' requires 'dep' to be loaded first. */
+static void
+add_module_dep (const char *name, const char *dep)
+{
+  struct moddep *m = xmalloc (sizeof *m);
+  m->next = moddeps;
+  moddeps = m;
+  m->name = xstrdup (name);
+  m->dep = xstrdup (dep);
+}
+
+static const char *
+get_module_dep (const char *name)
+{
+  struct moddep *m;
+
+  for (m = moddeps; m; m = m->next)
+    if (strcmp (m->name, name) == 0)
+      return m->dep;
+
+  return NULL;
+}