iPXE booting possibly broken on OS X Sierra Update
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@Seb-B Thanks for posting the link to the iPXE forum again. Haven’t noticed that there were new posts on that topic. Though I don’t think there is much news to what we already know. But still it’s good to know that another person is onto that. Seems like Curtis definitely knows the bits. I will try to contact him and see what we can do.
… it has to do with the firmware installed with Sierra (which will not be reverted if we switch back to El Capitan) so I don’t have much hope for that …
Are you sure about the firmware not being reverted? I kind of hoped (not knowing enough about Macs) that installing El Capitan would also install the old firmware version but possibly I am wrong. I still think it’s worth trying just so we know. In case this is irreversible I’d find this even worse.
It’s going to take some us time to try and revert to an El Capitan OS…
Couldn’t you just test this on one single client? Make a FOG backup of a machine that is known to have this PXE boot issue, pop in the El Capitan DVD and do a fresh clean install (removing all the Sierra stuff before)? That shouldn’t take very long, right?
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HI Sebastian,
I’m not sure either about the firmware, but it would seem strange to me that it would be reverted at the same time as the OS, but as I said we’ll try just to make sure.
“Make a FOG backup of a machine that is known to have this PXE boot issue”
well, I’d certainly love to be able to do that wouldn’t I
Seriously though, the clients are in use in a another building and have quite a load of heavy applications on it, so I would have to wait for one to be inoccupied for at least two days (one for the test, one for reverting to a usable state). I’ll chack the occupation planning of these room and try to get this done as soon as it can be.
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Hi,
so, we did try to revert a machine to El capitan but while the OS was no problem, the firmware didn’t downgrade on the way.
We looked for a way to force the firmware downgrade but couldn’t find any so far…The search continues…
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@Seb-B Thanks heaps for trying to downgrade and letting us know that this is not reversible. So this hope is gone. Once upgraded to Sierra the machine is “lost”.
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I just tried to boot ipxe.efi and snp.efi with new High Sierra update. It is the same thing. Nothing was fixed in High Sierra. I don’t know how to get this done.
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@P-Schnoeckel Thanks for testing! Would have been great if Apple had just fixed this for us. But they don’t. @fractal13 even got in contact with Apple but they refuse to give us details on what has changed in the UEFI firmware. So I think we need to figure this out ourselves…
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Thanks to @P-Schnoeckel I’ll have a chance to debug this issue on an iMac myself. He arranged to send me one of their machines at no cost. Thanks heaps for this!
Will keep you all posted about what I find…
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Hi everyone
has anyone had any more luck so far? Not that we have but maybe some of you…
Good luck all
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I’ve been working on the on and off over the last weeks. This is what I just sent to iPXE dev Michael Brown:
Tried looking at the NIC registers as suggested by NiKiZe in the forums a while back. Added ethtool code to dump registers to iPXE but from my tests it looks like many registers are different on every reboot and I have no idea which registers mean what. For now I don’t think this is getting us anywhere. But I am open to suggestions.
Digging through the tg3*.c code I figured that there might be some auto negotiation issue on the iMac model I have. Curtis did not seem to have that and got that sort of fixed. Now I am seeing the same thing as Curtis, interface comes up and it tries to send packets to wire but fails so. As far as I know Curtis has been onto this together with you on a IRC chat.
On the other lane I have tested the Linux code a fair bit. Tested 4.13.4, early 3.9 and the very first commit that added 57766 NIC support to the Linux kernel. I did test those early versions as I hoped to clarify if the later added binary firmware blob is playing a role or if any commit in the kernel code did fix an issue with Macs. Turns out it’s not from my tests. They all worked like a charm on the iMac that cannot send packets within iPXE.Hope we’ll find some time to give me some hints on where to dig next.
@Seb-B As well if you have ideas and suggestions on how to diff the tg3 code of iPXE and the Linux kernel to figure out what’s up. I have started to but there seem to be too many minor differences making it really hard to diff. Though I have the feeling that we should be able to solve this soon as Linux kernel is working great.
