Re: Wake on Lan the SERVER from Boot-Rom ?

[Bob Edwards <Robert.Edwards@anu.edu.au>]

Joachim Wolff wrote:
> 
> Hi all,
> 
> I like to wake up my "Server" from one of the diskless Client
> Boot-Rom's.
> 
> In 4.4.5 is the wol.c source in ./contrib/wakeonlan. I can build it and
> it works. But this program need a running OS.
> 
> I need to include this function to send the packets to two NICs
> before the bootp-request can be answered and the OS is loaded, because
> the "server" that should answer the bootp may be sleep at this time.
> ( It is for home use, so the "server" don't run 24x7 )
> 
> I know, the NIC-HW-adresses must include in the ROM, but I by two NIC's,
> so that one can fail later.
> 
> Can anybody tell me the way, etherboot build (for example the bootp)
> packages, so that i can modify the code to WOL packages?
> 
> Of cause, there is the source, but im an beginner in HW-near
> network programming. But PLEASE no referer to RFC's.
> 
> By
> 
> Joachim

This sounds like an interesting proposal. The only problem is that your
Diskless Client (DC) would have to have the MAC address of the server
somehow available for it's boot ROM - there is no way for the boot ROM to
discover the MAC address of the server without another server available.

So, apart from that, I see no particular reason why it wouldn't be possible
to hack the wol.c code into the boot ROM. Before you send out the bootp
request packet, just broadcast the wol magic packet with the servers MAC
address in it - then wait a couple of minutes for the server to boot up,
then go on with the bootp request.

Cheers,

Bob Edwards (author of wol.c).
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