Serial Console under FreeBSD
Having previously setup serial console access for Linux systems, here’s a recipe to do this for FreeBSD as well.
In my case, I needed it for a OOB (out of band) BMC (Baseboard Management Controller) from Dell (iDRAC), but it should apply to any system.
Create or add to (in a SINGLE LINE)
That will setup a “dual console” for the boot loader, mirroring i/o for the boot loader to both standard video console and the serial console. See also
boot.config(5) man pages.
boot_multicons="YES" boot_serial="YES" comconsole_speed="57600" comconsole_port="0x2f8" console="comconsole,vidconsole"
That completes the setup, providing sufficient hints to the loader to provide to the kernel to again mirror i/o to both serial and video consoles. See also
loader.conf(5) man pages.
Note two potentially unique options that may not map directly to your configuration:
comconsole_speed="57600"- for a slower, older machine.
com2), rather than default
In my case (Dell iDRAC), I needed to set the console interface to a different UART, hence the
comconsole_port= option, otherwise the default UART would be used. You should be able to find the address of the serial console via
dmesg, as in:
# dmesg | grep uart uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0 uart1: <16550 or compatible> port 0x2f8-0x2ff irq 3 on acpi0 uart1: console (57600,n,8,1)
For your case, best to confirm both com port and speed via the documentation for your BMC/DRAC/CMC/whatever.