How do I boot memtest86 to ttyS1,115200

[Journer]

I recently purchased a netgate sg-4860.  No issues, but I always like to give new hardware a run through memtest / prime95.

However, despite all my efforts, I can't get memtest to boot and display over the serial port.
I've tried memtest86 and 86+ with multiple boot disks (arch, ultimate boot cd, provided usb stick boot) as well as different boot overrides (append console=ttyS1,115200n8, etc.) but I can never get passed the initial "Memtest loaded… ok" prompt.

Any ideas?

[dreamslacker]

You will need to compile memtest with a separate flag to enable the console output.

See:

http://www.memtest.org/download/1.55/memtest86+-1.55/README

4) Serial Console
=================
Memtest86 can be used on PC's equipped with a serial port for the console.
By default serial port console support is not enabled since it slows
down testing.  To enable change the SERIAL_CONSOLE_DEFAULT define in
config.h from a zero to a one.  The serial console baud rate may also
be set in config.h with the SERIAL_BAUD_RATE define.  The other serial
port settings are no parity, 8 data bits, 1 stop bit.  All of the features
used by memtest86 are accessible via the serial console.  However, the
screen sometimes is garbled when the online commands are used.