We are testing FreeBSD 12.0-STABLE on some of our servers to prepare migration from FreeBSD-10 to FreeBSD-12. Our current svn info: URL: svn://svn.freebsd.org/base/stable/12 Relative URL: ^/stable/12 Basis des Projektarchivs: svn://svn.freebsd.org/base UUID des Projektarchivs: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f Revision: 350885 uname -a: FreeBSD dssbkp1.incore 12.0-STABLE FreeBSD 12.0-STABLE r350885 SERVER64 amd64 On older Intel Hardware (SR2400 / SR2500) we are not able to boot from disk with kern.vty="vt" (boot disk includes software raid - gmirror+gjournal, no zfs). Boot stalls immediately after starting the kernel (no matter if GENERIC or locally modified kernel is used). In serial console log we see: Booting [/boot/kernel/kernel]... panic: pmap_mapdev_internal: too many preinit mappings cpuid = 0 time = 1 KDB: stack backtrace: Uptime: 1s Booting with kern.vty="sc" works without any problem. Booting from an installation CD, created by "make cdrom" in /usr/src/release of this version (r350885) works too (vt). Booting this version on different hardware (HP DL360 G7) works as expected (same kernel version, gmirror+gjournal). One of these non-running servers was already mentioned in bug #236838 including dmesg output.
At last we found the culprit. There was a tunable set in loader.conf: debug.late_console="0" which caused this erroneuous behavior. After removing this line from loader.conf, the servers boot as expected with kern.vty unset. This PR can be closed.