The SIMCOM* Quad-band Mobile Sim900 – Arduino* Pack is actually validated to be compatible with the Galileo Gen2. You can even find a sketch on Shield Testing Report for Intel® Galileo Board and Intel® Edison Board. You will find the information about the Sim900 on page 164.
its optional, we code the GSM module with or without the header file.and i found the code too........... when I run the code its showing transfer complete but am not getting call and message.can anyone tell why it is so???????????