search for: o00000020

...boot sector, reports the magic bytes and and read-sector error code. Holding down a shift key during boot will force CHS mode even if LBA is detected. Detailed information on reported data and usage is in the header commentary of mbr/mbr-diag.S; here is an example: DIAG L D80h C3FFh H10h S3Fh P1 O00000020 MAA55h E00h which means: [L]BA addressing mode (alternative is [C]HS), [D]isk 0x80, [C]ylinders 0x3FF, [H]eads 0x10, [S]ectors 0x3F, [P]artition active 1, [O]ffset to boot-sector 0x00000020, [M]agic bytes (of boot-sector) 0xAA55, [E]rror code (from AH=0x42/0x02, int 0x13) 0x00...

...even if LBA is detected. Holding down a Ctrl key will force loading the boot-sector from the first hard-disk regardless of the BIOS drive-number in DL. Detailed information on reported data and usage is in the header commentary of mbr/mbr-diag.S; here is an example: DIAG L D80h C3FFh H10h S3Fh P1 O00000020 MAA55h E00h which means: [L]BA addressing mode (alternative is [C]HS), [D]isk 0x80, [C]ylinders 0x3FF, [H]eads 0x10, [S]ectors 0x3F, [P]artition active 1, [O]ffset to boot-sector 0x00000020, [M]agic bytes (of boot-sector) 0xAA55, [E]rror code (from AH=0x42/0x02, int 0x13) 0x00...

...active partition. Value is reset to 0xDEAD before the sector is read + to avoid inheriting the MBR magic on error + E error error code returned by BIOS 'read sector' interrupt (0x02 or 0x42, int 0x13). + '??' if no active partition. + + Examples: + L D81 C3D9 HFF S3F P1 O00000020 MAA55 E00 + C D80 C3D9 HFF S3F P1 O00000020 M0000 E04 + + Usage: + # set device to write diagnostic MBR to + DEV=/dev/sdc + # back-up existing MBR + sudo dd if=$DEV of=mbr-backup.bin bs=440 count=1 + # write diagnostic MBR to device + sudo dd if=mbr-diag.bin of=$DEV + # example: test in a virtual m...