Packet mode for boot0/mbr

Matthew Dillon dillon at
Wed Jan 7 23:38:42 PST 2009

:I think the hard drive size limitation is around 8GB for CHS.  Any larger=
:drive will have to use packet mode anyways.  The problem is that even for=
:smaller drives/reads below 8GB if OS and BIOS don't agree on CHS, booting=
:won't work.  Packet mode is really a stone old interface by now.
:   simon

    Unfortunately some BIOSes emulate packet mode, which is why it doesn't
    always work.  Most should get it right these days but I think we still
    need the option to use CHS.  The BIOSes that emulate packet mode take
    the logical sector number, translate it to CHS, and then translate it
    back.  It's that bad.


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