I went on vacation and left my hackintosh sleeping in order to reduce power draw. I was hesitant to do that, because sleep is a good way to crash my hackintosh. Sure enough, I came home and ironically my machine's fans were running on high with the wall power monitor showing 170w draw, with the displays off and the machine completely unresponsive.
Oh well, I reset the machine and expected it to boot. It did not.
It would get through OC, allow me to select the boot drive, and then the verbose boot text output for macOS would get partway through and either bootloop or hang after showing the
I was concerned that somehow the CPU had been cooked or a PCI device had failed. I booted from an ubuntu live USB and everything was fine. The drives seemed okay in gparted, albeit unmounted/could not be inspected due to lack of apfs support in linux. I reviewed the OC boot logs, but those were not instructive because the crash/bootloop was happening after the OC handoff to macOS.
I then booted memtest86 and let it run a pass, no errors.
I was about to pull my fenvi bluetooth PCI card to see if it was the issue, but then I decided to review my BIOS settings. I checked above 4G decoding, PCI bifurcation, XHCI handoff/legacy support, all good. Then I got to CSM Support. Oh... it was enabled. Clearly I had not changed that, because macOS does not work at all with that enabled. Toggled that back off and everything booted fine again.
FWIW, I already hated Gigabyte's A/B BIOS for switching back and forth at weird times, so that has been disabled for years on this AORUS Master X570 motherboard, implying that the machine changed its settings on this single BIOS on its own. Furthermore, the UPS log for this machine shows that there were no power failures while I was on vacation, so this uncommanded config change can't be attributed to a power blip.
I decided to post this writeup in case it happens to someone else and a forum search could give them an easy win.
tl;dr: Gigabyte BIOS can change its configuration without user input. If your machine suddenly becomes unbootable, double check the BIOS settings to see if it "helped you out".
Oh well, I reset the machine and expected it to boot. It did not.
It would get through OC, allow me to select the boot drive, and then the verbose boot text output for macOS would get partway through and either bootloop or hang after showing the
AMDCPUSupport::start Family 19h, Model 03hline. I tried booting from another known good NVMe and it repeatedly got to a mangledLiluline before hanging.I was concerned that somehow the CPU had been cooked or a PCI device had failed. I booted from an ubuntu live USB and everything was fine. The drives seemed okay in gparted, albeit unmounted/could not be inspected due to lack of apfs support in linux. I reviewed the OC boot logs, but those were not instructive because the crash/bootloop was happening after the OC handoff to macOS.
I then booted memtest86 and let it run a pass, no errors.
I was about to pull my fenvi bluetooth PCI card to see if it was the issue, but then I decided to review my BIOS settings. I checked above 4G decoding, PCI bifurcation, XHCI handoff/legacy support, all good. Then I got to CSM Support. Oh... it was enabled. Clearly I had not changed that, because macOS does not work at all with that enabled. Toggled that back off and everything booted fine again.
FWIW, I already hated Gigabyte's A/B BIOS for switching back and forth at weird times, so that has been disabled for years on this AORUS Master X570 motherboard, implying that the machine changed its settings on this single BIOS on its own. Furthermore, the UPS log for this machine shows that there were no power failures while I was on vacation, so this uncommanded config change can't be attributed to a power blip.
I decided to post this writeup in case it happens to someone else and a forum search could give them an easy win.
tl;dr: Gigabyte BIOS can change its configuration without user input. If your machine suddenly becomes unbootable, double check the BIOS settings to see if it "helped you out".
