Hi, Alexander E. Patrakov wrote: > The following variants, obtained by changing only the MBR, also work: > 1. Type-0 one-sector bootable partition at the very first sector: > 000001d0: 0100 0000 0200 0000 0000 0100 0000 0000 ................
Did you create this by partition editor or by dd ? While trying to mimick it, i wonder whether the "0200" should not be "0100". I understand that the value "02" is in byte 468 = 0x1d4: Sector part of C/H/S address of last absolute sector in partition 2. (Plus 2 bits from cylinder part which are 0.) A partition from LBA 0 with 1 blocks should have C/H/S range 0/0/1 to 0/0/1, not 0/0/1 to 0/0/2. (I am not sure how to express the end C/H/S of an empty partition at LBA 0. 0/0/0 is not really a valid C/H/S.) ------------------------------------------------------------------ There is a new GNU xorriso development snapshot uploaded http://www.gnu.org/software/xorriso/xorriso-1.4.3.tar.gz MD5 5163f97f5ce9a7707ac7de6777b46283 For a proof-of-concept i have added two macros which enable the production of a dummy MBR partition like with Alexander's recent experiments. To be unpacked and built by tar xzf xorriso-1.4.3.tar.gz cd xorriso-1.4.3 && ./configure && make Test the executable standalone binary by xorriso/xorriso -version which should yield ... xorriso version : 1.4.3 Version timestamp : 2015.12.22.133736 ... You may use it by its absolute address with grub-mkrescue --xorriso=... I hopefully fixed the bug with partition type 0xee with HFS+ if no GPT emerges. It should now be 0x83 or 0xcd depending on the presence of option --protective-msdos-label . Test proposals with add-on partition of type 0x00: - Variation 1 In ./xorriso-1.4.3 do export CPPFLAGS=" -DLibisofs_protective_msdos_plus_boot_dummY" ./configure && make clean && make If option --protective-msdos-label is present, and there emerges only one partition of type 0xee with no boot flag, then a second MBR partition gets addedd with same geometry as the first one, but with type 0x00 and boot flag. MBR partition table: N Status Type Start Blocks MBR partition : 1 0x00 0xee 1 32251 MBR partition : 2 0x80 0x00 1 33251 - Variation 2 In ./xorriso-1.4.3 do export CPPFLAGS=" -DLibisofs_protective_msdos_plus_boot_dummY" CPPFLAGS="$CPPFLAGS -DLibisofs_pmpbd_on_lba0" ./configure && make clean && make Under the same criteria as with Variation 1, the added second MBR partition starts at LBA and has only 1 block. MBR partition table: N Status Type Start Blocks MBR partition : 1 0x00 0xee 1 32251 MBR partition : 2 0x80 0x00 0 1 - Back to normal In ./xorriso-1.4.3 do unset CPPFLAGS ./configure && make clean && make I would be thankful for reports about tests with grub-mkrescue and the picky machines. (The partition adder code is on display at http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/revision/1296/libisofs/system_area.c ) Have a nice day :) Thomas _______________________________________________ Bug-grub mailing list [email protected] https://lists.gnu.org/mailman/listinfo/bug-grub
