1) Grub installs its own INT13 handler
2) Near the end of the chain loading process, Grub loads an image of
the
Linux kernel into memory which wipes out their Int13 handler.
3) Right before grub transfers control to the kernel to boot, grub
makes a
call to a function to turn off the floppy drive.
4) The call to the floppy code then makes an Int13 call to the handler
which has been overwritten by the kernel and thereby results in the
red screen.
This text seems to be contradictory. INT13 handler is installed if
drivemap is useful only with chainload. But then it mentions Linux
loading. Also the call to stop floppy doesn't call BIOS:
static inline void
grub_stop_floppy (void)
{
grub_outb (0, GRUB_FLOPPY_REG_DIGITAL_OUTPUT);
}
May I see the configfile in question?
Also GRUB does calculate the safe place based on memory layout,
looking at code I see the problem that it's calculated before
installing drivemap hook. While this should be fixed, I see no reason
to use drivemap with Linux.
_end quoted text_
Regards,
Iain Barker - Platform Engineering, Acme Packet.
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--
Regards
Vladimir 'φ-coder/phcoder' Serbinenko
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