[ipxe-devel] Booting a Mac into WDS with ipxe.usb (was: Re: gPXE or iPXE on USB)

Robin Smidsrød robin at smidsrod.no
Wed Jun 19 20:19:08 UTC 2013

On 19.06.2013 21:03, Yadin Flammer wrote:
> Thanks for the reply Robin, the answer was buried in your one
> statement.  Ubuntu apparently doesn't actually write the output of dd to
> the device until you issue an eject command from command line.  If you
> just pull the drive, no changes are written to it, unlike if you're
> using it normally dragging and dropping files. Important footnote for
> the inexperienced, and very odd (if not deficient) compared to other
> platforms.

Well, you're writing directly to the block device instead of using
high-level file routines. It's understandable that you need to flush the
device cache for that kind of activity.

> Anyway, now that I can actually get the .usb cloned to USB, I face a
> different set of issues.
> Some Mac systems simply will not see the drive as bootable, others
> will.  I suspect this has to do with the vintage of the firmware and the
> type of file system that's being written to the drive.  For those that
> will boot from it, here's what fails:

I've heard on the list a while back that some Macs boot in legacy/BIOS
mode when booting with CD, but boot in UEFI mode when booting using USB.
If that is the case on your Mac, then no amount of trying to write the
BIOS version of iPXE to a USB stick will work.

> With iPXE, it comes up fine (as from CD as well) to the point I choose a
> boot image from the WDS server.  After you choose an image, it should
> start the Windows boot process, and from any normally booted PXE system
> (or from gPXE on CD) it does so just fine.  iPXE does not work for some
> reason.  It can't actually start transferring data and therefore start
> the boot process from the look of it, because it stops on BOOT.SDI and
> the progress bar never moves.  So from all experience so far, iPXE has a
> fault in some odd way where it can talk to the WDS server to present the
> boot image list, but then it can't actually start booting for some
> reason, regardless of what media you've booted iPXE from (CD or USB).  I
> have also verified this on a Dell, so it's not some Mac only behavior,
> iPXE just doesn't work for some reason where gPXE did (from CD at least,
> again on any Mac or Dell).

Can you give us a screenshot/picture of what's going on? My guess is you
might be dealing with a driver strangeness, especially if you're using
the existing bnx2 (Broadcom) driver. I'd recommend you try to build with
DEBUG=bnx2,tg3 to see if you get any more info out of it. Also, when you
boot up iPXE, what value do you have for "chip" when using the "config"

> Thoughts?  I'm fine with some trick to make iPXE actually boot a WDS
> image if that's the supported product, or if there is a way to make gPXE
> work from USB the same as from CD that's fine by me as well.

The first thing is to start showing us what you're actually doing
instead of just talking about it. Details, details, details! To be able
to debug remotely we need logs, hardware details and descriptions of
your setup and what you're trying to do. It would also be useful to
understand what your end goal is, maybe you're going about it in the
wrong, or unoptimal, way.

-- Robin

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