grub2/grub2-setup-try-fs-embed-if-mbr-gap-too-small.patch

Index: grub-2.02~beta2/util/setup.c
===================================================================
--- grub-2.02~beta2.orig/util/setup.c
+++ grub-2.02~beta2/util/setup.c
@@ -501,8 +501,44 @@ SETUP (const char *dir,
       err = grub_util_ldm_embed (dest_dev->disk, &nsec, maxsec,
 				 GRUB_EMBED_PCBIOS, &sectors);
     else if (ctx.dest_partmap)
-      err = ctx.dest_partmap->embed (dest_dev->disk, &nsec, maxsec,
-				     GRUB_EMBED_PCBIOS, &sectors);
+      {
+        err = ctx.dest_partmap->embed (dest_dev->disk, &nsec, maxsec,
+				       GRUB_EMBED_PCBIOS, &sectors);
+#ifdef GRUB_SETUP_BIOS
+	if (err == GRUB_ERR_OUT_OF_RANGE
+	    && strcmp (ctx.dest_partmap->name, "msdos") == 0
+	    && dest_dev->disk->id == root_dev->disk->id
+	    && dest_dev->disk->dev->id == root_dev->disk->dev->id)
+	  {
+	    grub_fs_t root_fs;
+
+	    root_fs = grub_fs_probe (root_dev);
+	    if (root_fs && root_fs->embed)
+	      {
+		grub_disk_addr_t *fs_sectors;
+		unsigned int fs_nsec;
+
+		fs_sectors = NULL;
+		fs_nsec = core_sectors;
+		err = root_fs->embed (root_dev, &fs_nsec, maxsec,
+				      GRUB_EMBED_PCBIOS, &fs_sectors);
+		if (!err && fs_nsec >= core_sectors)
+		  {
+		    grub_util_info ("Your msdos embedding area is too small, will use file system embedding area instead");
+		    sectors = fs_sectors;
+		    nsec = fs_nsec;
+		    ctx.container = root_dev->disk->partition;
+		    core_dev = root_dev;
+		  }
+		else
+		  {
+		    if (fs_sectors)
+		      grub_free (fs_sectors);
+		  }
+	      }
+	  }
+#endif
+      }
     else
       err = fs->embed (dest_dev, &nsec, maxsec,
 		       GRUB_EMBED_PCBIOS, &sectors);
@@ -584,7 +620,7 @@ SETUP (const char *dir,
 
     /* Write the core image onto the disk.  */
     for (i = 0; i < nsec; i++)
-      grub_disk_write (dest_dev->disk, sectors[i], 0,
+      grub_disk_write (core_dev->disk, sectors[i], 0,
 		       GRUB_DISK_SECTOR_SIZE,
 		       core_img + i * GRUB_DISK_SECTOR_SIZE);