Hi, i wrote > > dd if=/dev/sdX bs=512 count=1 | od od -t x1
Renato Bispo wrote: > the command you sent didn't work: A copy+paste error indeed. A single "od" would have been right. > 0000000 b8fa 1000 d08e 00bc b8b0 0000 d88e c08e A bit pattern widely known to the web. http://superuser.com/questions/317372/editing-mbr-for-flash-device advises to use "parted" and predicts that this code will be on the medium. Other than gparted, parted is in my scope. So i try dd if=/dev/zero bs=4M count=1 >test.img /sbin/parted test.img mklabel msdos dd if=test.img bs=512 count=1 | hexdump and get 0000000 b8fa 1000 d08e 00bc b8b0 0000 d88e c08e 0000010 befb 7c00 00bf b906 0200 a4f3 21ea 0006 0000020 be00 07be 0438 0b75 c683 8110 fefe 7507 0000030 ebf3 b416 b002 bb01 7c00 80b2 748a 8b01 0000040 024c 13cd 00ea 007c eb00 00fe 0000 0000 ... [empty partition table] ... 00001f0 0000 0000 0000 0000 0000 0000 0000 aa55 So the prescription would be to let parted (or frontends) install its MBR, to create a partition with boot flag, to re-isohybridize a Debian i386 or amd64 ISO image, and to put it into the partition. This is to be executed only once before any other partitions get created on the USB stick. end_megabyte minus start_megabyte must offer enough room to take the ISO image. dev=/dev/sdc start_megabyte=1 end_megabyte=316 image_path="$HOME/Downloads/debian-8.2.0-i386-netinst.iso" sudo /sbin/parted "$dev" mklabel msdos sudo /sbin/parted "$dev" mkpart primary $start_megabyte $end_megabyte sudo /sbin/parted "$dev" set 1 boot on isohybrid --partok "$image_path" dd if="$image_path" of="$dev" bs=1M This is expected to boot via BIOS but not via EFI (unless BIOS emulation). One may now create more partitions and populate them with filesystems, e.g. another isohybrid --partok ISO. One of those which contain bootable MBRs can be selected by part_number=3 sudo /sbin/parted "$dev" set $part_number boot on Now i wonder whether this procedure works for you, or whether i made a copy+paste mistake again. (I did not use /dev/sdc but rather test.img.) Have a nice day :) Thomas
