[Libre-soc-dev] versa_ecp5.py paramaterization update

Luke Kenneth Casson Leighton lkcl at lkcl.net
Tue Oct 13 04:18:59 BST 2020

crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

On Tue, Oct 13, 2020 at 3:15 AM Cole Poirier <colepoirier at gmail.com> wrote:

> Well I’m glad at least ppc64 is already gdb. So the server remote serial
> protocol needs to be implemented for the chip?


JTAG TAP is already done and is not a remote protocol.

the *test* programs (firmware_upload.py, test_jtag_tap_srv.py) which
connect *to* JTAG i have implemented the *openocd* jtagremote protocol
"for convenience", by turning what was formerly a nmigen-only
simulation test program (test_jtag_tap.py) into a *pair* of processes
separated by the openocd jtagremote network protocol.

this separation *has nothing to do with the chip*

this separation *has nothing to do with JTAG TAP HDL*

the only connection is that the jtagremote protocol happens to send
bits back and forth that allows transfer of jtag bit-banging "raise
TCK now please", "lower TDO now please", "i'm letting you know that
TDI got lowered now".

we do not need a gdb-server developer

we do not need a gdb developer

if we need anyone we need - and this is very very specific - a
developer to add ppc64 support to openocd which implenents the
microwatt-inspired DMI protocol over the JTAG-DMI gateway that i had
to design a couple weeks ago.

i found a patch that added or1k many years ago that shows exactly how
that's done: it's not difficult, it's just time.

in the meantime the programs such as firmware_upload.py although slow
make it unnecessary and no longer a hard critical dependency to have
ppc64 openocd "support"


More information about the Libre-soc-dev mailing list