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iMAC with Broadcom 14e4-1686 BCM57766 : link status down
2017-03-13, 13:19
Post: #17
RE: iMAC with Broadcom 14e4-1686 BCM57766 : link status down
(2017-03-10 09:12)speleo14 Wrote:  
(2017-03-09 18:01)NiKiZe Wrote:  In that case I only think that boot ROM might be relevant.

I agree. I have now tested 2 iMacs, both were bought at the same time (spring 2016). One was upgraded to Sierra (10.12), the other is still on Capitan (10.11).
The 10.12 iMac has Boot-ROM IM171.0105.B15, and doesn't PXE boot ("link down").
The 10.11 iMac has Boot-ROM IM171.0105.B05, and PXE booting does work.
So the Sierra upgrade does also upgrade the Boot-ROM, and this breaks booting with iPXE.
The SMC version does not seem to be relevant, both have 2.33f10.

Currently checking if the Boot-ROM can be downgraded... but not much hope.

(2017-03-09 18:01)NiKiZe Wrote:  Does any of these work with snponly.efi?

Will try and post back.
OK, built snponly.efi with "make bin-x86_64-efi/snponly.efi".

Trying to boot with that results in "No more network devices" on all machines, that is, no NICs were even recognized (neither internal nor external).

This, to me, (This is the "Tom" referred to above about the developer of FOG.) sounds exactly like a firmware issue.

Maybe we need to go to Apple and somehow file a Firmware issue? While I'm not sure how Apple feels about PXE Booting machines, the fact remains, from what I can tell here, that they pushed an update and that update broke something unexpectedly. These Mac's aren't going away anytime soon, and updating firmware to limit potential areas of boot seems like a rather large 'exploitation' of customer's own rights when purchasing machines.

I don't know who we would talk to, but I really doubt this is a problem from FOG or iPXE, but rather some "fix" Apple added to the ROM information on the NIC. Whether this was intentional or not I don't know.

One of the problems I've had with Apple is they tend not to care about the consumer and treat the customers as if they're temporary borrowers of their equipment. They're typically helpful if you do have an issue and are in their support terms, but the moment your warranty or "apple care" expires, they're really quick to try to make you go out and buy new equipment. I'm still not sure how to report a bug like this with Apple, though I'm certain somebody knows how somewhere.

Sorry about the vent there. Supporting Mac's should not be this difficult and it seems anytime a new update comes out for "Apple" devices, a new issue is broken and rarely does there seem to be a fix implemented.
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RE: iMAC with Broadcom 14e4-1686 BCM57766 : link status down - mastacontrola - 2017-03-13 13:19

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