[syslinux] Problem with pxelinux 5.0 and memtest

[H. Peter Anvin]

On 04/03/2013 09:54 AM, Matt Fleming wrote:
> On 03/04/13 15:11, H. Peter Anvin wrote:
>> I don't think we can... in an error condition we need it.
> 
> In that case, how about building logic into the shuffler code so that it
> understands it can reclaim the PXE stack region, even those it's
> currently marked as reserved?
> 

Well, we'd mark that in the map we feed the shuffler.  That part is easy
enough.

The problem is that if the unload is successful, then we're ok, but if
the unload is not successful -- and that does happen on real systems --
we are stuck.

Overall it feels like we don't have any good options here.  We have
similar issues with stubs that need to be in high DOS memory too (used
by the chainloader), so it isn't entirely unique to this case.  It's a
fundamental problem with PXE.

What we *might* be able to do is to see if we have a memory map which is
impossible and in that case, switch to "optimistic mode".

	-hpa