[ipxe-devel] iPXE with Virtualbox

[Andrew Bobulsky]

Hello Pete,

Good info there.  I'm running an AMD system, and disabling AMD-V
similarly worked to allow the lkrn to boot.

Out of curiosity, I tried something kinda funny.  I went into
src/i386/transitions/libflat.S and put some comments around line 423,
"call flatten_real_mode".  That appears to be the function where the
GDT is shuffled around into and then back out of PM.  Compiled it,
and, with AMD-V off, it still boots, pulls DHCP, and so on.  Broke to
the command line, initrd'ed a 136MB ISO, and then chained it with
GRUB4DOS as a mem mapped disk.  Booted just fine. :P

Cheers,
Andrew Bobulsky

On Mon, Jan 24, 2011 at 10:44 AM, Pete I. Eby <ebypi at ornl.gov> wrote:
> Hi Andrew, Michael, and Matthew,
>
> With this new information I did a bit more testing with Virtualbox.
> First, I upgraded to the newer version of VirtualBox (4.0.0). I then
> tried booting using an iPXE 1.0.0 .iso and of course it locked up when
> loading ipxe.krn.
>
> I then selectively changed the CPU settings. I thought perhaps the NX
> and / or VT cpu features might be contributing this to.
>
> Turns out that if you disable VT support, it will allow it to boot. (It
> also loads with with NX enabled.)
>
> The intricacies of VT and it's relation to unreal mode are foreign to me
> honestly, but at least this allows a temporary work around.
>
> Cheers,
> Pete
>
>
>
>