iMAC with Broadcom 14e4-1686 BCM57766 : link status down

[letouzey]

Update : I've also tried on many other Mac Mini 7,1 in our lab room, ipxe works great on them !
So the only problematic machine is the macmini 7,1 I used for initial testing. AFAICT this problematic machine has the exact same hardware as the other ones, but a slightly different system on it. In particular, the firmware is more recent (2017 instead of 2015). But I'm not sure yet that this recent firmware is to blame, it could be other settings like Apple SIP mode enabled or not. I'll continue some experiments to see if I can pinpoint which difference is causing the ipxe issue.

For now, I can just say that:
- many Macmini 7,1 with firmware MM71.88Z.0220.B03.1506051117 (dated 6/5/2015) do work fine
- one Macmini 7,1 with firmware MM71.88Z.0220.B29.1706181928 (dated 6/18/2017) is having the "link down" issue with ipxe.

Best,
Pierre Letouzey