difference between bit stream in bit file and SVF file.

[madan_ratnakar]

Hey!

I have a .bit file for Xilinx spartan 6 FPGA . I generated the SVF file for the .bit file that I have. I know that the .bit file is byte reversed ( each byte is bit reversed) but there are other differences as well in the file that I have, for example there are some hex values which are different while there are also some values extra in the end of the .bit file. I do not know/ understand these differences.

I am making my own Jtag programming utility using the Digilent HS1 cable and was sending the .bit file as the configuration file. There were some issues so I thought of taking a clue from the SVF file but now I am stuck here and do not know what to do!

Kindly help!

Regards

 

[mrflibble]

Sounds intriguing. If I may ask, why make your own utility? As for your specific question ... dunno. When reverse engineering just get yourself some more data to stare at. As in, get a few more bit+svf files of various content and see if you detect a pattern.

Either that, or just grab the source from other utils (for digilent boards) by other people. Which obviously is option numero uno before starting to stare at bitfiles. So I'll just assume you already did that.

 

[madan_ratnakar]

Sounds intriguing. If I may ask, why make your own utility? As for your specific question ... dunno. When reverse engineering just get yourself some more data to stare at. As in, get a few more bit+svf files of various content and see if you detect a pattern.

Either that, or just grab the source from other utils (for digilent boards) by other people. Which obviously is option numero uno before starting to stare at bitfiles. So I'll just assume you already did that.

Hey, I am doing it for an organization, and no, I didnt look at sources of other utils, could you point me to some?

Thanks!

 

[mrflibble]

https://www.google.com/search?q=nexys2_prog

That should get you started...