Re: Mapping Video BIOS?

From: M. Warner Losh <imp_at_bsdimp.com>
Date: Sun, 27 Jul 2003 22:03:57 -0600 (MDT)
In message: <20030728040157.GP45069_at_wantadilla.lemis.com>
            "Greg 'groggy' Lehey" <grog_at_FreeBSD.org> writes:
: Sure.  The data at offset 0xc0000 are:
: 
: C000:0000  55 AA 78 E9 44 06 00 00-00 00 00 00 00 00 00 00   U.x.D...........
: 
: The 0xaa55 is the BIOS signature ("Here be a BIOS"), and the 0x78 is
: the length byte (120 sectors, or 60 kB).  That's how orm0 knows the
: end address.
: 
: > I don't think that it suggests that things are 'unmapped'...
: 
: If the area between 0xcc000 and 0xcffff had been mapped, orm0 would
: have found this too:
: 
: C000:F000  55 AA 08 E8 6D 0B CB 11-FE 02 00 00 00 00 00 00   U...m...........

08 -> 4k

It could also be that there's a bug in orm that's missing it...

Warner
Received on Sun Jul 27 2003 - 19:06:04 UTC

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