Add script to reconfigure AFCv3.1 and AFCv4.0 FPGA via XVC

[augustofg]

This script assumes that openocd with XVC support is installed and in PATH.

[gustavosr8]

Have you tested it? I don't really understand the scansta and boot commands (maybe it would be nice to add a comment explaining them), but the bash part seems good to me.

[augustofg]

Have you tested it? I don't really understand the scansta and boot commands (maybe it would be nice to add a comment explaining them), but the bash part seems good to me.

Yes, I've tested it. The scansta SVF file contains the JTAG commands to change the SCANSTA111 JTAG switch to select the FPGA (necessary for AFCv3.1 cards). The boot SVF file has the JTAG commands to make the FPGA reconfigure itself from the non-volatile SPI flash.

[ericonr]

It would be nice to document in the commit that this was based on the scripts from fpga-programming, and also explain why it diverges in some points.

The FREQUENCY in the svf scripts is different, the sfp_jtag line as well, and some further device properties (though part of those could have been folded into cpld/xilinx-xc7.cfg?)

[ericonr]

As discussed, the scripts from fpga-programming will be updated to match the ones here.

(though some parts, such as frequency setting, will probably be removed)

[augustofg]

FREQUENCY command removed from SVF files.