Brent Gardner

Forget all that. openFPGALoader (https://github.com/trabucayre/openFPGALoader) is ready as-is (after compiling/installing), with no need to compile first.bit. It also automatically resets the device (loads program from SPI flash). For the CmodA7: openFPGALoader -c digilent --fpga-part xc7a35tcpg236 -f your_design.bit

Brilliant, @charkster! I was able to get it to work on a Raspberry Pi as well as 64-bit Ubuntu. To further assist others, here are some additional notes: The CmodA7 does not need them, but the latest FTD2XX drivers are available from https://ftdichip.com/drivers/d2xx-drivers/. If you don't need them, replace "cmake .." with "cmake -DUSE_FTD2XX=OFF .." when compiling xc3sprog. I couldn't get them to install properly on a Pi. Select the appropriate archive for your architecture and extract: tar -xfv libftd2xx-[architecture]-[version].gz You may need the "z" flag as well, as it seems that FTDI mixed up their file extensions, and the downloads may be an uncompressed tarball. Follow the instructions in the extracted release/ReadMe.txt file to install the FTD2XX libraries. When compiling xc3sprog on a non-Raspberry Pi, replace "cmake .." with "cmake -DUSE_WIRINGPI=OFF ..". I had some issues with my USB connections during programming, either read/write errors, timeouts, or disconnections, especially on the Pi. Using compressed bitstreams seemed to help, as well as using "jtaghs1" instead of "jtaghs1_fast". I'm not sure if this has anything to do with the relatively high 66MHz CCLK set in constr.xdc. Running with the verbose flag helps identify these issues, so I recommend the one-liner: xc3sprog -v -c jtaghs1_fast -Ifirst.bit your_design.bit Note that first.bit leaves the blue LED turned on, and the change in red LED state is only in brightness due to the high rate of change. The CmodA7 requires a power cycle to load the program from SPI flash.