[ipxe-devel] Using iPXE, e820 RAM map badly changed, kernel panic over seeing only 50MB

[james harvey]

On Mon, Aug 8, 2016 at 10:28 PM, james harvey <jamespharvey20 at gmail.com> wrote:
>
> Awesome.  I'd prefer to stick with bios mode, skipping EFI.
>
> I switched from using "make bin/15b3673c.rom" to "make
> bin-x86_64-pcbios/15b3673c.rom"  That changed the size of the .rom
> from 77,824 bytes to 88,064 bytes, but sadly doesn't fix the BIOS E820
> call error.
>
> I used "DEBUG=hidemem,memmap", and did my usual pressing Ctrl+B to
> enter iPXE.  I then saw:
>
>     iPXE (PCI 06:00.0) starting execution...Fetching system memory map
>     FBMS base memory size 625 kB [0,9c400)
>     INT 15,88 extended memory size 65535 kB [100000, 40ffc00)
>     INT 15,e801 not available during POST
>     INT 15,e820 not available during POST
>     INT 15,e820 failed; constructing map
>     ...
>
> ARGH!  I get what's going on.  It might be nice to add a warning (even
> without debugging on) if someone tries to boot through coming in using
> Ctrl+B during POST.
>
> My MSI X99S SLI Plus BIOS acts weird with the Mellanox InfiniBand card
> with iPXE on it.  In the Hard Drive Priorities menu, it shows iPXE and
> lets me select it, but then immediately makes another selection
> beneath it of one of my SATA drives.  If I disable the SATA drive, it
> disables iPXE too.  If I leave them both there, in the boot order
> options it only lets me select the SATA drive, doesn't even show me
> iPXE.  Entering the boot menu doesn't even show iPXE as an option.
>
> This is with the BIOS LAN Option ROM on, and even turning the UEFI
> Network Stack option on, it still doesn't let me uniquely use it
> without picking a SATA.
>
> If my BIOS isn't picking up seeing the Mellanox card, are my only
> options to go with a different motherboard or to start booting through
> the onboard NIC?

New BIOS upgrade for the X99S SLI Plus, either the one in June or
July, at least makes it so I can boot iPXE on the Mellanox card
through the manual boot menu.  It still doesn't let me select it as a
default boot option.

But going this way, everything seems fine with the E820 map.  No more
kernel panic.


I'd still suggest a warning if someone's trying to boot having come in
using Ctrl+B during POST (I was using sanboot), but this at least
isn't a bug in the iPXE e820 code as I thought.