Smc=0x2 - SMC is short for system management controller, which is what’s responsible for the battery, fans, sensors, and thermal management. The setting 2 seems to prevent the AMD chip from powering down. Thus allowing these to be loaded without testing if they are indeed signed.” This has been replaced by SIP after 10.10.Īgc=2 - This seems related to automatic graphic switching between Intel and AMD Radeon GPU drivers. Kext-dev-mode=1 - This “is intended for development scenarios where you want to test unsigned kernel extensions. Rootless=0 - “Rootless (a security mechanism making its debut in El Capitan 10.11) restricts access to certain files, even as an administrative user, such as is provided by ‘sudo’.

What did they do? I went on a googling spree to find out what all of these do. Having my main computer run with unknown boot-args did worry me. (If you’re curious what these args do, some are documented here, and there are some more if you look toward the Hackintosh scene.) Are These Dangerous? Apple replaced most of the machine, so it came with a fresh install of macOS… and some interesting boot-args that they forgot to clear. I didn’t set any of these, but previously, I’d had to send my 16-inch MacBook in for repairs, as it had corrupted memory, resulting in extremely weird bugs and frequent kernel panics. I posted about this on Twitter to learn more, but while nobody could tell me what was up, a friend noticed that I have “ fun boot-args.” WTH? Panic(cpu 2 caller 0xffffff8014016487): 'AppleIntelFramebuffer::setPowerState(0xffffff835c3b6000 : 0xffffff7f975f5d88, 1 -> 0) timed out after 45938 (CPU 2), Frame : Return AddressīSD process name corresponding to current thread: kernel_taskīoot args: rootless=0 kext-dev-mode=1 agc=2 smc=0x2 watchdog=0 nvme=0x9 legacy_hda_tools_support=1 sandcastle=0 amfi_hsp_disable=1 chunklist-security-epoch=0 -chunklist-no-rev2-dev

Smc fan control kernel panic