Syslinux - Nov 2002 - ISOLINUX & AWARD 6.00PG BIOS

Hi Peter,

thanks for SYSLINUX/ISOLINUX/PXELINUX!

Some comments regarding ISOLINUX and the AWARD 6.00PG BIOS:

If a CD drive and at least one HD drive is present in the machine,
everything works fine :-)

IF a CD drive is the _only_ drive of the PC isolinux (and any other
program that uses no-emul-boot) will fail :-((
CD floppy-emul-boot or harddisk-emul-boot will work.

IF a CD drive is the _only_ drive of the PC, but the user defined a
nonexistant 
HDD "manual", using "CHS" and "halt on no errors",
isolinux will work
;-)

I modified isolinux-debug to give more detailed bug reports before
failing and discovered that
this is not a bug of isolinux but a bug of the AWARD BIOS. The problem
is that AWARD initalizes the
int 13h vector to different places, depending on the configuration of
the machine. 

Everything works fine if a hard disk is present, defined in the BIOS or
emulated on CD --- the INT 13 vector
will be initialized correctly.

Otherwise, the BIOS initializes the INT 13 vector to a place that does
not give access to INT 13 4Bxx etc :-((

Possible workaround: If INT 13 4B01 fails, scan for an AWARD Bios and
the location of the correct INT 13
entry point, initialize the INT 13 vector and go on. 

I tried this with a quick'n dirty hack, it works fine. If you are
interested in the code I 
could clean it up and add the scan part (I hardcoded the correct vectors
for my machines)

cu,
 Knut



Knut Petersen
Mittelgasse 4a
D-36329 Romrod

Knut Petersen wrote:
> 
> Possible workaround: If INT 13 4B01 fails, scan for an AWARD Bios and
> the location of the correct INT 13
> entry point, initialize the INT 13 vector and go on. 
> 
> I tried this with a quick'n dirty hack, it works fine. If you are
> interested in the code I 
> could clean it up and add the scan part (I hardcoded the correct vectors
> for my machines)
> 
Would you know how to find it for other Award BIOS machines?  Remember 
that BIOSes are actually compiled by the platform vendors, so the 
different platforms would have a different address map even with the 
same BIOS.

If you can find it, go ahead and send it to me... then I'll decide if I 
can stomach it :)

	-hpa