Re: Replacing the legacy "map" command

["Vesa Jääskeläinen" <chaac@nic.fi>]

Javier Martín wrote:
> Bit a bit, progress continues: I have some crappy UI semi-ready, to
> improve on later, and I'm now battling with the INT13h handler to
> perform the actual mapping - had to rescue the big old "Architecture
> Programmer's Manual" in order to do PIC code without the amd64
> rip-relative addressing. However, I haven't yet found a way to install
> some kind of "hook" so that it will be called when the boot command is
> issued, preferable just before calling grub_X_real_boot. However, I
> didn't go to great lengths to find it... Anyone here willing to
> enlighten me or should I find my own way through the darkness (again
> ¬¬)? I'd like to change/add the smallest amount of code possible, but
> for the sake of modularity I prefer a pre-boot hook system rather than
> a one-time solution.

Hi Javier,

There is no existing hook for this kind of stuff. So why not make one 
pointer to boot area where you can register one?. Code would then check 
if it is non-zero and call it before starting OS. Pointer would reside 
on same asm module as low level boot code is to keep it close by and 
helper on C-level to modify that pointer. You may want to support also 
multiple callbacks some way.

Thanks,
Vesa Jääskeläinen