[syslinux] pxelinux implementation questions

[Alexander Sack]

Hi,

I've been looking at the pxelinux code and I was wondering a couple of
things:

1)  Why does pxelinux create UDP packets from scratch instead of use the
Intel PXE TFTP OPEN/CLOSE/READ calls?  I'm assuming this is to support
TFTP options like tsize right?  Did earlier versions of pxelinux use the
TFTP calls directly?

2)  How big of an image can pxelinux download (minus memory constraints)?  
My understanding is that tftp packet numbers are from 0-65535 yielding a 
maximum size of 32MB.  Yet, from the revision history, it seems pxelinux 
can handle bigger images?  (I don't see any wrap around handling though
I maybe not looking hard enough in seachdir() - from the looks of it,
the only way I can see pxelinux downloading a bigger image is if the
tftp_blksize is negotiated greater than 512, right?)

3)  Why does pxelinux require tsize?  Does it make a difference what
size the file is as long as the last packet returns < 512?

Sorry if these topics have been covered before (I did attempt to search
through the archives for answers - I got bits and pieces).

Thanks!

-aps

-- 
"Linux is OBSOLETE."
-Andrew Tanembaum