Hi,
I use the official sdk,
see
https://www.mobileread.com/forums/showthread.php?t=19406
Download the official SDK package. Unpack it to "/". You should see a "/usr/local/arm" after unpacking. If you unpack it to somewhere else, error may occur during compile. The official SDK already contains needed libs, such as gtk, poppler, eripc, scribble...
you will need to type:
"export PATH=/usr/local/arm/oe/bin:$PATH".
"export CC=arm-linux-gcc".
"export CXX=arm-linux-g++".