wget http://armadillo.atmark-techno.com/files/downloads/armadillo-420/source/kernel/linux-2.6.26-at22.tar.gz
wget http://armadillo.atmark-techno.com/files/downloads/armadillo-420/source/dist/atmark-dist-20150127.tar.gz
tar zxvf linux-2.6.26-at22.tar.gz
tar zxvf atmark-dist-20150127.tar.gz

ln -s atmark-dist-20150127 atmark-dist
cd atmark-dist
ln -s ../linux-2.6.26-at22 linux-2.6.x

make config
  config/mkconfig > config.in
  * Vendor/Product Selection
  *
  * Select the Vendor you wish to target
  *
  Vendor (3com, ..., Arnewsh, AtmarkTechno, Atmel, ..., senTec)
[AtmarkTechno] AtmarkTechno
  *
  * Select the Product you wish to target
  *
  AtmarkTechno Products (Armadillo-210.Base, ..., Armadillo-300,
Armadillo-420, Armadillo-420.WLAN-AWL12, ..., SUZAKU-V.SZ410-SIV)
[Armadillo-420] Armadillo-420
  *
  * Kernel/Library/Defaults Selection
  *
  * Kernel is linux-2.6.x
  *
  Cross-dev (default, arm, armel) [default] default
  Libc Version (None, glibc, uC-libc, uClibc) [None] None
    defined CONFIG_DEFAULTS_LIBC_NONE
  Customize Kernel Settings (CONFIG_DEFAULTS_KERNEL) [N/y/?] n
  Customize Vendor/User Settings (CONFIG_DEFAULTS_VENDOR) [N/y/?] n
  Update Default Vendor Settings (CONFIG_DEFAULTS_VENDOR_UPDATE) [N/y/?] n

make dep all #config, kernel and userland
make # kernel and userland
make romfs; make image #userland
make linux; make image #kernel

sudo cp images/linux.bin.gz /var/lib/tftpboot/
sudo cp images/romfs.img.gz /var/lib/tftpboot/

picocom --baud=115200 /dev/ttyUSB0
hermit> tftpdl 192.168.1.110 192.168.1.109 --kernel=linux.bin.gz --userland=romfs.img.gz