--- /dev/null
+/* 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;
+}
git.annexia.org / febootstrap.git / blobdiff