SIM900A firmware upgrade on Gnu/Linux.

Hello.

I am currently trying to get a SIM900A board to work with my Arduino. The board is not set up to work in Europe by default.So It needs a firmware upgrade in order to work here.

Someone wrote a program that can upgrade the firmware. The problem (for me) is that this program is written for Windows.

I have access to the firmware I need to install on the board. My question is. How do i go about upgrading the firmware without using the custom software ?