[J-core] Avnet LX9 microboard support & programming?

[Forest Crossman]

OpenOCD has support for flashing SPI flash chips attached to Xilinx
3-, 6-, and 7-series FPGAs through its jtagspi driver. You can find an
example script in board/pipistrello.cfg[1]. Of course, flashing this
way would require either an external JTAG dongle or support in OpenOCD
for the embedded JTAG adapter on that board. Unfortunately, since it
looks like a microcontroller handles that, we'd probably have to
reverse engineer Digilent's code and write our own driver. The good
news is, once you have a the driver written, you're done, since the
jtagspi flash driver only needs a JTAG interface and a flash proxy
bitstream[2][3] to work.

If someone wants to donate/lend me one of those FPGA sticks, I could
probably write a full JTAG driver for it in a few months (assuming the
protocol isn't completely terrible).

[1]: https://sourceforge.net/p/openocd/code/ci/master/tree/tcl/board/pipistrello.cfg
[2]: https://github.com/jordens/bscan_spi
[3]: https://github.com/jordens/bscan_spi_bitstreams

-- 
Forest Crossman