Re: [Etherboot-discuss] AoE boot (was: iSCSI boot)

[Michael B. <mb...@fe...>]

On Tue, 30 May 2006, Valeriy Glushkov wrote:
>> Yes, but not in a very usable form.  If there is interest, I can put up 
>> a precompiled .dsk image for RTL8139 to demonstrate AoE booting.
> Thank you! But I have no RTL8139 near me, so unable to test the loader. 
> :( Are there any plans to port it to the PXE API instead of direct NIC 
> hardware usage?

Technically, you could use the Etherboot UNDI driver to run it over an 
underlying PXE stack.  The Etherboot UNDI driver hasn't been updated to 
the new driver API yet, however.  Also, it's uncertain how safe it would 
be to do this, because the underlying PXE stack might use regions of 
memory that the loaded OS expects to own.

>> Once the OS has loaded, it will be running its native iSCSI/AoE driver, 
>> and so can mount whatever it wants.  The only exception to this is DOS, 
>> and if anyone wants to add an INT 13,EB (add/remove physical drive) 
>> call and an accompanying HOTPLUG.COM utility, they're welcome!
> My interest is in booting Windows 2000+ from an AoE device. For that 
> purpose the initial loader should install the int 13h handler for the 
> hard drive to be used by ntloader to bootstrap.

NTLDR should already be able to bootstrap.  However:

> I guess having an AoE loader that works well for DOS should be enough 
> for booting Windows from it, isn't it?

Not necessarily.  Windows doesn't have a nice, clean initrd-like concept. 
Boot drivers will be loaded using INT 13, then the boot drivers will be 
started.  So far, so good; just mark the AoE driver as a boot driver. 
However, I don't think that you can mark an NDIS driver as a boot driver. 
This means that the AoE driver would load, but would have no network card 
with which to communicate in order to continue the boot.

I'm looking into the possibility of creating a stub Windows disk driver 
that continues using INT 13 for the few seconds it takes to get to the 
point of having loaded the network stack.

Isn't Windows fun?

Michael