Re: calling UNDI API

[Johan Rydberg <jrydberg@night.trouble.net>]

Marco Gerards <metgerards@student.han.nl> wrote:

: > GRUB doesn't assume that hardware interrupts occur during normal
: > execution, since this makes the implementation very complex, due to
: > the switch between real mode and protected mode on i386. So I prefer
: > the polling approach to the interruption-based approach. For this,
: > Etherboot fits gracefully.
: 
: Ok, I agree.

Isn't GRUB executing in protected mode, except when it escapes into
real mode to do BIOS calls?  I can not see how it would be difficult
to use interrupts in such context.  Or does the BIOS depend on 
interrupst?
 
: > BTW, do you really need TCP in GRUB? I know some people want to use TCP 
: > protocols for netboot, such as HTTP and FTP. But I feel this is 
: > overkill. If you need only UDP, it's quite easy to implement. You can 
: > just copy the code from GRUB Legacy with a few modifications for 
: > portability.
: 
: No, I just said TCP/IP because I am used to it and it is the name of
: the protocol, I did not mean TCP specifically.  But I know a lot of
: people would like TCP support.  It is at least an option that should
: be left open, IMHO.

The problem is that TCP is rather interrupt driven by nature.  For 
example, it uses a lot of timers for packet re-sending and similar
stuff.

Maybe it is possible to use lwIP, which is released under a modified
BSD license.  See http://savannah.nongnu.org/projects/lwip/

~j