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

[Rob Landley]

On 08/31/2016 12:29 AM, Forest Crossman wrote:
> 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've got one (with the lx45 repot) sitting on a dresser in Austin. I
haven't used it since I mailed the sdcard adapater for it to Rich Felker.

Unfortunately, I'm in San Diego at the moment, but I could probably get
Fuzzy to mail it to to you if you can get me an address (and Jeff thinks
that's a good use of the board; I mostly test on Numato these days
because it's so darn _convenient_, but also have Turtle and and EVB
prototypes).

> 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

Jeff: opinion?

Rob