tree aacafb870c2adab0b6b719ab34ec6917815609f7
parent fd498ca0d94b66feab407cf0762e90d260df2afd
author Rupert Swarbrick <rswarbrick@lowrisc.org> 1619699717 +0100
committer Rupert Swarbrick <rswarbrick@gmail.com> 1623163917 +0100

[rom_ctrl] Enable connection to KMAC

This changes the meaning of the SkipCheck parameter once again.
Before, it disabled the connection with KMAC (essentially making KMAC
seem to return after a single cycle, with a digest of '1) and then
also disabled the comparison with the expected contents.

After this commit, rom_ctrl does the handshaking with KMAC and
calculates whether it matches. The only thing that SkipCheck now
controls is the "good" signal sent out to the pwrmgr. We can't
get *that* working yet, because we don't yet model the cSHAKE digest
calculation in the Python code, so can't put the right values in the
top of ROM.

This change should hopefully mean that synthesis results give roughly
the right area, even when SkipCheck is set: since the calculated
digest is exposed as a "DIGEST" register, the synthesis tool will be
forced to generate all the flops to hold it's (not feasibly
predictable) value.

As well as the changes to the rom_ctrl code, we also make a small
modification to chip_common_vseq, so that it waits to see rom_ctrl run
to completion before it starts issuing TL transactions. See the
comment in the new code for details.

Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>