--- src/mkdosfs.c.bootcode	2011-10-01 08:11:39.728024787 +0400
+++ src/mkdosfs.c	2011-10-01 08:13:15.412024824 +0400
@@ -280,6 +280,7 @@
 static char *program_name = "mkdosfs";	/* Name of the program */
 static char *device_name = NULL;	/* Name of the device on which to create the filesystem */
 static int atari_format = 0;	/* Use Atari variation of MS-DOS FS format */
+static const char *bootcode_srcimage = NULL;  /* Source file/device from which read bootloader code */
 static int check = FALSE;	/* Default to no readablity checking */
 static int verbose = 0;		/* Default to verbose mode off */
 static long volume_id;		/* Volume ID number */
@@ -794,6 +795,24 @@
     return sectors;
 }
 
+static void
+apply_external_bootcode(void)
+{
+  if ( !bootcode_srcimage )
+    return;
+  char *bootcodeptr = ( size_fat == 32 ) ?
+    ( (char*) &bs.fat32.boot_code ) : ( (char*) &bs.oldfat.boot_code );
+  int offset = ( int )( bootcodeptr - (char*)&bs );
+  int nbytes = ( size_fat == 32 ) ? BOOTCODE_FAT32_SIZE : BOOTCODE_SIZE;
+  int srcfile = open( bootcode_srcimage, O_RDONLY );
+  if ( srcfile < 0 )
+    die("Cannot open device/file for reading source bootloader code");
+  if ( lseek( srcfile, offset, SEEK_SET ) < 0)
+    die("Cannot seek to begin of source bootloader code");
+  if ( read( srcfile, bootcodeptr, nbytes ) != nbytes )
+    die("Cannot read source bootloader code");
+}
+
 /* Create the filesystem data tables */
 
 static void
@@ -842,6 +861,9 @@
 			(char *)&bs.oldfat.boot_code) -
 		       (char *)&bs) - 2;
 
+    if (bootcode_srcimage) {
+        apply_external_bootcode();
+    } else
     if (size_fat == 32) {
 	int offset = (char *)&bs.fat32.boot_code -
 		     (char *)&bs + MESSAGE_OFFSET + 0x7c00;
@@ -1423,7 +1445,7 @@
 {
   fatal_error("\
 Usage: mkdosfs [-a][-A][-c][-C][-v][-I][-l bad-block-file][-b backup-boot-sector]\n\
-       [-m boot-msg-file][-n volume-name][-i volume-id]\n\
+       [-m boot-msg-file][-n volume-name][-i volume-id]  [-B bootcode-image ]\n\
        [-s sectors-per-cluster][-S logical-sector-size][-f number-of-FATs]\n\
        [-h hidden-sectors][-F fat-size][-r root-dir-entries][-R reserved-sectors]\n\
        /dev/name [blocks]\n");
@@ -1488,7 +1510,7 @@
   printf ("%s " VERSION " (" VERSION_DATE ")\n",
 	   program_name);
 
-  while ((c = getopt (argc, argv, "aAb:cCf:F:Ii:l:m:n:r:R:s:S:h:v")) != EOF)
+  while ((c = getopt (argc, argv, "aAB:b:cCf:F:Ii:l:m:n:r:R:s:S:h:v")) != EOF)
     /* Scan the command line for options */
     switch (c)
       {
@@ -1500,6 +1522,10 @@
 	align_structures = FALSE;
 	break;
 
+      case 'B':
+        bootcode_srcimage = optarg;
+        break;
+
       case 'b':		/* b : location of backup boot sector */
 	backup_boot = (int) strtol (optarg, &tmp, 0);
 	if (*tmp || backup_boot < 2 || backup_boot > 0xffff)
--- man/mkdosfs.8.bootcode	2011-10-01 08:14:09.000000000 +0400
+++ man/mkdosfs.8	2011-10-01 08:15:04.192024792 +0400
@@ -12,6 +12,10 @@
 .B \-A
 ]
 [
+.B \-B 
+.I source-bootcode-container
+]
+[
 .B \-b
 .I sector-of-backup
 ]
@@ -109,6 +113,15 @@
 option. Some PC-specific boot sector fields aren't written, and a boot
 message (option \fB\-m\fP) is ignored.
 .TP
+.BI \-B " source-bootcode-container "
+By default \fBmkdosfs\fP writes bootsector containing dummy code
+that does nothing except displays stupid message. If you want to create
+bootable DOS diskette and are ABSOULTELY sure that it has the same format
+as another already existing diskette (most important is difference
+between FAT and FAT32), you can extract boot loader from it.
+\fIsource-container\fP should be device file like /dev/fd0,
+as well as regular file like /mnt/windows/bootcode.dos
+.TP
 .BI \-b " sector-of-backup "
 Selects the location of the backup boot sector for FAT32. Default
 depends on number of reserved sectors, but usually is sector 6. The