Spkmodem

Howto

Warnings

• Spkmodem will make your boot an order of magnitude slower, be warned
• On the Lenovo X60 the output stops after the EC is initalized => press the volume up button on your keyboard when that happens, it should restore the logs...
• Don't use gdb trough serial and spkmodem at the same time... you won't be able to connect to the target trough gdb and the computer will be stuck waiting for gdb.

Receiving

Download grub's trunk:

bzr branch http://bzr.savannah.gnu.org/r/grub/trunk/grub
cd grub

Compile the receiver code:

cd util
gcc -o spkmodem-recv spkmodem-recv.c

Run it like that if you have pulseaudio:

parecord --channels=1 --rate=48000 --format=s16le | ./spkmodem-recv

Or like that for alsa:

arecord -c 1 -r 48000 -Dplughw:0 -f S16_LE | ./spkmodem-recv

Coreboot part

Configure coreboot like that:

make menuconfig

Go in console:

Console  --->

Select spkmodem

[*] spkmodem (console on speaker) console output