The bundled vi package with dreambox really sucks ! and I am a big fan of nano text editor , as always I was disappointed to find a rebuilt nano package in Gemini or even dreamboxupdate repos , so I searched the net and wonderfully found a nano package which works with my dm800 
instruction to install nano :
cd /sbin wget http://downloads.nas-central.org/LS2_MIPSel/Packages/mipsel-nano_2.0 mv mipsel-nano_2.0 nano chmod +x nano