I am running FreeBSD 8.2-RELEASE. The machine is a Supermicro 5015M with a IPMI 2.0 daughterboard.

When I boot this host, the boot process proceeds fine. I see the BIOS, the RAID BIOS, the first and second stage boot loader and the Stage Three, /boot/loader. These all appear to work fine, and there is no problem with the speed.

Then, the system loads the Kernel and messages from the kernel print at about 1 bps. Here's a video of the IPMI KVM-over-LAN. I also see this when using a physical keyboard-video-mouse attached to the machine.

The BIOS console redirection is set to be 115200 bps.

The relevant settings from /boot/loader.conf and /boot/device.hints:


I have deactivated boot_multicons, boot_serial, set comconsole_speed to various values, changed console to various values, etc. Nothing works. It's as if the Kernel is ignoring the settings that I type into the loader. I have even changed the port speed in the BIOS.

Any idea why this is happening?

It appears that FreeBSD is printing character to the Video console, but is printing the characters at a speed intended for the serial console, and mistakingly assumes that my serial console is configured at 1 bps.

  • 1
    FYI, a workaround for people in this situation. When you get to the loader, Escape to the loader prompt, type set boot_mute=YES to (prevent Kernel messages from being sent to the screen)[freebsd.org/cgi/…, and the system should finish booting in a regular amount of time. Apr 26, 2012 at 1:19

1 Answer 1


If anyone can explain why this happens, please post your own answer. If you answer is good, I'll accept your answer over mine.

The quick and easy solution, choose the other COM port. Apparently I had a mismatch between COM A, COM B, which are called 03F8 and 02F8 in other places. The BIOS was configured to use COM A. The FreeBSD bootloader settled on some sane defaults, which is why the bootloader behaved fine. The FreeBSD kernel were expecting to see COM B. COM A was unconfigured in the Operating System, and thus the kernel settled on some strange defaults (1 bps). The bps rate of the serial console also affects the speed of text printed to the video console.

Keep in mind that I wasn't using the serial console, but we always configure the serial consoles on our systems so that IPMI's Serial-over-LAN (SOL) works, as some of the sysadmins here prefer SOL.

I swear I tried this before and it didn't work. But now, it works.

It might also be possible to prevent this by twiddling with uart settings in /boot/device.hints .

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