Re: ELKS 0.0.81 available from ftp.ecs.soton.ac.uk

[Blaz Antonic]

> This is unverified, but
> I think the Basic-hook is still there, untouched.
> But some of the EPROM area reserved for Basic has been used for the setup
> subprograms.
> So we are back to the usual problem, where in the 640 kB should we put or own
> EPROM.

Nowhere. There is a memory area meant for ROMs above 640 KB. It is
called UMB. That's where VGA BIOS, Network card boot ROM, special (SCSI
and alike) adapter BIOS ROMs are.

All you have to do is to insure your ROM image uses correct format
(utils in netboot package create correct images from executable
binaries) and BIOS will do the rest of the job - it will detect the ROM,
fetch its size and start address and start executing code from it. It is
up to you (ROM) to return control to BIOS (and let it boot normaly) or
execute kernel and boot into your OS (that's the way you want it if you
imaplnt a ROM inthere).

                                                bye, Ab