Solaris net boot from Linux

I've spent a couple of hours Googling for this with limited success.
Can anyone point me at any FAQs/HOWTOs/whatever that covers this? My
problem is:

1) I have 2 dead UltraSPARC/SunOS 5.x boxes, and I need to do a net
boot of some sort so that I can carry out surgery on them

2) I have a Centos/x86 box that I would like to use as the boot server
(note that this isn't a Jumpstart installation: I just want to boot,
so that I can then manually mount disks, edit the password file, and
so on; hopefully the SunOS machines will be able to boot themselves
afterwards)

3) I have another working SunOS machine, so I could presumably use the
kernel from this one, but it might be easier to use a generic Linux
SPARC kernel (if I can find one somewhere!)

4) I can't use the working SunOS machine as the boot server, since it
doesn't have the boot server installed, and I don't have the CDs

The 'network booting service' on out-of-the-box RHEL/Centos doesn't
seem to be appropriate; as far as I can make out, it only handles
Jumpstart installations if you've altready got a CD (which I haven't).

Thanks -

Paul

The easiest solution for your situation is to download the free solaris
iso's from www.sun.com and burn the cds to disc. Then boot into single
user mode from the cd and mount your internal disks, then do whatever
repairs you need to. If you want specific instructions, let me know I
will provide them for you.

As for the network boot from Linux, it is possible to do but it is a
little more invloved than the cd solution. You will need a solaris
kernel on the linux box and setup DHCPD with the Solaris boot
extensions. It is the same as setting up for a jumpstart but again you
just boot single user mode from the network. I can give those
instructions too, but it is less favorable over the CD solution.