[ipxe-devel] [Realtek]: Possible bug - cannot load ipxe when intel-sata controller is set to RAID
mbrown at fensystems.co.uk
Tue Apr 16 12:46:04 UTC 2013
On 16/04/13 08:12, Joshua C. wrote:
> > Glad the patch works for you. Unfortunately it can't be applied as
> > a general solution. If PMM allocation fails (which is not
> > uncommon), then iPXE has no way to shrink itself, so we have to be
> > pessimistic in reporting our runtime size.
> Is there a way to test at runtime if PMM works? If so maybe this can
Yes. Unfortunately, the decision on what runtime size to advertise in
the ROM's PCI header has to be taken at _build_ time; it's a static
field, and by the time we get to execute our first instruction, the BIOS
has already read the value in the field.
> I've been wondering of the manufactorer can do something about this
Unfortunately not; it's an architectural limit intrinsic to the way
If iPXE were allowed to load first, then you may find it works even
without a patch. If PMM works, then iPXE will reduce its runtime image
below the pessimistic estimate advertised via the ROM's PCI header, and
there should then be enough space left in the 128kB for the Intel ROM to
Since you are adding the ROM into the BIOS flash, you may be able to
alter the order in which ROMs are loaded by adjusting the order within
the flash image.
> I'll explain to them what caused the problem as
> well as why they cannot reproduce it at their side. On the other
> hand I have an efi-bios which should be capable of overcomming the
> limitations of the old pc-bios.
EFI is completely unaffected by this limit, if you're using a native EFI
iPXE ROM. (Most EFI systems also include a BIOS emulation layer,
allowing you to use a standard BIOS iPXE ROM; if you're using this then
you're still subject to the same 128kB limit.)
To build a native EFI iPXE ROM, you would do:
> Any ideas if and how the
> manufacturer can help (if they're willing to do so, of course)?
Try adjusting the order of ROMs within the flash. If this doesn't help,
ask if there's any way you can alter the order in which ROMs are loaded.
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