===== GnuRadio and rtl-sdr on RaspberryPi =====

==== Building on RPi ====

  * 3 GB of space in / for build-dependencies
  * swap (linking takes up to 1 GB RAM)
  * build-space (prefeably over network or on USB HDD to avoid destroying SD card)
  * compilation takes ~24 hours

NBD server example:<code>
/etc/nbd-server/config:
[generic]
[export]
    exportname = /dev/mapper/group-pishare
    port = 2001
    authfile = /etc/nbd-server/pi

/etc/nbd-server/allow:
192.168.0.203

mkfs.ext3 /dev/mapper/group-pishare
mount /dev/mapper/group-pishare /mnt
dd if=/dev/zero of=/mnt/swap bs=1M count=1500
mkswap /mnt/swap
umount /mnt
</code>

On RPi:
<code>
apt-get install nbd-client
modprobe nbd
nbd-client 192.168.0.23 2001 /dev/nbd0
mount /dev/nbd0 /mnt
swapon /mnt/swap
</code>

Use script [[http://www.sbrac.org/files/build-gnuradio|build-gnuradio]]. When it fails, compile gnuradio [[https://lists.gnu.org/archive/html/discuss-gnuradio/2012-07/msg00266.html|with soft FPU]]:
<code>
cd gnuradio/build
cmake -Dhave_mfpu_neon=0 -DCMAKE_CXX_FLAGS:STRING="-march=armv6 -mfpu=vfp -mfloat-abi=hard" -DCMAKE_C_FLAGS:STRING="-march=armv6 -mfpu=vfp -mfloat-abi=hard" ../
make
sudo make install
</code>

Croscompilation: TODO