automake commit without merge history

grub-core/loader/i386/pc/chainloader.c

@@ -0,0 +1,173 @@
+/* chainloader.c - boot another boot loader */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2002,2004,2007,2009,2010  Free Software Foundation, Inc.
+ *
+ *  GRUB 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 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/loader.h>
+#include <grub/machine/loader.h>
+#include <grub/machine/chainloader.h>
+#include <grub/file.h>
+#include <grub/err.h>
+#include <grub/device.h>
+#include <grub/disk.h>
+#include <grub/misc.h>
+#include <grub/types.h>
+#include <grub/machine/init.h>
+#include <grub/partition.h>
+#include <grub/machine/memory.h>
+#include <grub/dl.h>
+#include <grub/command.h>
+#include <grub/msdos_partition.h>
+#include <grub/machine/biosnum.h>
+#include <grub/i18n.h>
+#include <grub/video.h>
+#include <grub/mm.h>
+
+static grub_dl_t my_mod;
+static int boot_drive;
+static void *boot_part_addr;
+
+static grub_err_t
+grub_chainloader_boot (void)
+{
+  grub_video_set_mode ("text", 0, 0);
+  grub_chainloader_real_boot (boot_drive, boot_part_addr);
+
+  /* Never reach here.  */
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_chainloader_unload (void)
+{
+  grub_dl_unref (my_mod);
+  return GRUB_ERR_NONE;
+}
+
+static void
+grub_chainloader_cmd (const char *filename, grub_chainloader_flags_t flags)
+{
+  grub_file_t file = 0;
+  grub_uint16_t signature;
+  grub_device_t dev;
+  int drive = -1;
+  void *part_addr = 0;
+
+  grub_dl_ref (my_mod);
+
+  file = grub_file_open (filename);
+  if (! file)
+    goto fail;
+
+  /* Read the first block.  */
+  if (grub_file_read (file, (void *) 0x7C00, GRUB_DISK_SECTOR_SIZE)
+      != GRUB_DISK_SECTOR_SIZE)
+    {
+      if (grub_errno == GRUB_ERR_NONE)
+	grub_error (GRUB_ERR_BAD_OS, "too small");
+
+      goto fail;
+    }
+
+  /* Check the signature.  */
+  signature = *((grub_uint16_t *) (0x7C00 + GRUB_DISK_SECTOR_SIZE - 2));
+  if (signature != grub_le_to_cpu16 (0xaa55)
+      && ! (flags & GRUB_CHAINLOADER_FORCE))
+    {
+      grub_error (GRUB_ERR_BAD_OS, "invalid signature");
+      goto fail;
+    }
+
+  grub_file_close (file);
+
+  /* Obtain the partition table from the root device.  */
+  drive = grub_get_root_biosnumber ();
+  dev = grub_device_open (0);
+  if (dev && dev->disk && dev->disk->partition)
+    {
+      grub_disk_t disk = dev->disk;
+
+      if (disk)
+	{
+	  grub_partition_t p = disk->partition;
+
+	  if (p && grub_strcmp (p->partmap->name, "msdos") == 0)
+	    {
+	      disk->partition = p->parent;
+	      grub_disk_read (disk, p->offset, 446, 64,
+			      (void *) GRUB_MEMORY_MACHINE_PART_TABLE_ADDR);
+	      part_addr = (void *) (GRUB_MEMORY_MACHINE_PART_TABLE_ADDR
+				    + (p->index << 4));
+	      disk->partition = p;
+	    }
+	}
+    }
+
+  if (dev)
+    grub_device_close (dev);
+ 
+  /* Ignore errors. Perhaps it's not fatal.  */
+  grub_errno = GRUB_ERR_NONE;
+
+  boot_drive = drive;
+  boot_part_addr = part_addr;
+
+  grub_loader_set (grub_chainloader_boot, grub_chainloader_unload, 1);
+  return;
+
+ fail:
+
+  if (file)
+    grub_file_close (file);
+
+  grub_dl_unref (my_mod);
+}
+
+static grub_err_t
+grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),
+		      int argc, char *argv[])
+{
+  grub_chainloader_flags_t flags = 0;
+
+  if (argc > 0 && grub_strcmp (argv[0], "--force") == 0)
+    {
+      flags |= GRUB_CHAINLOADER_FORCE;
+      argc--;
+      argv++;
+    }
+
+  if (argc == 0)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, "no file specified");
+  else
+    grub_chainloader_cmd (argv[0], flags);
+
+  return grub_errno;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(chainloader)
+{
+  cmd = grub_register_command ("chainloader", grub_cmd_chainloader,
+			       0, N_("Load another boot loader."));
+  my_mod = mod;
+}
+
+GRUB_MOD_FINI(chainloader)
+{
+  grub_unregister_command (cmd);
+}