[syslinux] Question about pxelinux and gpxelinux

[H. Peter Anvin]

Sean Lv wrote:
> Dear Hpa and Jeffrey, thanks a lot for your kindly help and clarification. 
> 
> For the second question, I searched the google whole day without any luck. And I got the confirm from one of Microsoft engineer, MS DHCP server do not support forced-DHCP-option, like ISC DHCP.  Anyone has a non-official trick?   
> 
> I have an idea related to my 2nd question. Since gpxelinux.0 takes place of vendor-PXE stack, is there any way to force gpxe-PXE stack request the specified DHCP option? Then, I think MS DHCP could provide all options that gPXE client requested.  I guess it's related to re-compile gpxelinux.0, which is beyond my knowledge :)  
> 
> I tried to interrupt the gpxelinux.0 boot process by crtl+B, then I could manually set some parameters, such as boot file name, default gateway. If the manual work can be replaced by a configuration file? How to do it? For example, I should put a file named gpxe.conf in the same path with gpxelinux.0 on my tftp server.
> 
> Thanks in advanced.
> 

Arguably the Right Thing[TM] would be for pxelinux to issue a DHCPINFORM
packet asking for additional options.  What you describe above should
work too, although I'd like to get rid of the second DHCP in gpxelinux.
 You may want to ask on the Etherboot list about that; it doesn't sound
like it would be hard to do and would be beneficial in general.

There is a trick, however, which is probably easier: PXELINUX accepts
these options both as "normal" options and as vendor encapsulated
options.  I believe all known PXE stacks request the vendor encapsulated
option.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.