I set my kernel to boot up verbose using
sudo nvram boot-args="-v"
These logs are what I wanted to see, but how can I view the log after booting? I searched all log files without success.
dmesg did not show me the entire boot log but only the last few 100 lines of it, which was not enough.
What works for me (on macOS 10.12.6) to see all boot messages is this command:
sudo log show --predicate "processID == 0" --start $(date "+%Y-%m-%d") --debug
It shows all of today's kernel msgs, including the boot process.
If you only want the msgs since reboot, enter the date and time manually, like this, in 24h format:
sudo log show --predicate "processID == 0" --start "2018-10-28 13:19:00" --debug
(The "sudo" part is currently not necessary, but it doesn't harm, either.)
Right after booting use
dmesg -- display the system message buffer
You must be
root to display the system message buffer.
The log should be printed out to the standard system log in Yosemite and later, at
Prior to Yosemite, the kernel log is at