etherboot-developers

Re: [Etherboot-developers] Re: [Etherboot-users] start remoteboot from running dos

[Ken Y. <ke...@nl...>]

>Now, it is likely that we could figure out which code is needed, take it 
>from a kernel, assemble it in, and off we go.  Of course, why not just 
>use a .COM file anyway, since it isn't the case that we can parse or use 
>most of the options being passed via LOADLIN anyway.

The problem is that .com files rely on a clean environment. Loadlin does
the useful service of cleaning up all the junk that is loaded in a
typical DOS or Windoze setup.

>FREEDOS, load a config, and let Etherboot load a kernel without any DHCP 
>server.  A win in some environments.  Once the kernel is loaded, we're on 
>the air.
>
>So, what do you think?  Does it have potential?  

I'm not interested in hacks that bypass IP address management. Even
disked Windoze uses DHCP. That should give you a hint of the ire you
will get from sysadmins when they hit a rogue workstation that
unilaterally takes an IP address and causes problems for other hosts on
the network.

What is it with DHCP? You'd have to setup a TFTP and NFS server anyway.
If it's a problem working with existing DHCP servers, I'd rather pursue
approaches that allow the boot ROM to pick the right DHCP server, which
is what the vendor-class-identifier is about.

Re: [Etherboot-developers] Re: [Etherboot-users] start remoteboot from running dos

[Marty C. <md...@th...>]

On 11/30/2000 10:42 PM Ken Yap ke...@nl... wrote:
>The problem is that .com files rely on a clean environment. Loadlin does
>the useful service of cleaning up all the junk that is loaded in a
>typical DOS or Windoze setup.

After a fair bit of effort I have been able to get LOADLIN to load an 
Etherboot image.  Unfortunately, it hangs just before running the kernel 
(after TFTP and the netboot loader copyright messages).  I suspect that 
LOADLIN is loading something in an unexpected (for Etherboot) location, 
and it can't find the kernel entry after it loads.  It's around here 
somewhere :-)
LOADLIN does some very twisted things to memory to try and deal with 
DOS/Windows, and there's only so much faking out we can do in Etherboot.

Perhaps having gotten this far, people more intimate with loaders and 
LOADLIN might have suggestions.  I'll debug it some more after resting.

>I'm not interested in hacks that bypass IP address management. Even
>disked Windoze uses DHCP. That should give you a hint of the ire you
>will get from sysadmins when they hit a rogue workstation that
>unilaterally takes an IP address and causes problems for other hosts on
>the network.
>What is it with DHCP? You'd have to setup a TFTP and NFS server anyway.
>If it's a problem working with existing DHCP servers, I'd rather pursue
>approaches that allow the boot ROM to pick the right DHCP server, which
>is what the vendor-class-identifier is about.

I understand your point.  I think there are environments where people 
need the flexibility of Etherbooting without having control of or access 
to a DHCP/BOOTP server.  TFTP and NFS are different from BOOTP/DHCP in 
that one doesn't have to do broadcasts to get to them, and there isn't 
all of this "Multiple DHCP Servers considered harmful" interference.  
Heck, one could tftp a kernel from almost anything, and then NFS mount 
from another machine.

I think the issue is worth thinking about, even if it's not likely to 
make it into the standard distribution.

Regards,

Marty

---
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