Phil Dennis-Jordan opened issue #1: Logging service that's more reliable than IOLog/os_log at Phil Dennis-Jordan / kextgizmos

Phil Dennis-Jordan
2020-12-06T20:36:38Z

kprintf has been my go-to basic logging/tracing mechanism for kexts. Unfortunately, it currently doesn't seem to work on Apple Silicon. (It leads to a kernel panic if you set the debug=0x8 bit in boot-args and connect a FireWire adapter) IOLog is unreliable, and os_log doesn't seem to work at all.

A good way to solve this is to implement an IOResources-matching service with a user client that uses an IOSharedDataQueue of arbitrary buffer size to push snprintf()-generated messages to a user space helper tool.