Initial cut
checkpoint which compiles and runs but there is some off-by-1 in the protocol
Debugging the clock crossing logic
checkpoint which works
Clean up the AsyncMailbox black box
This is an unavoidably invasive commit, because it affects the unit tests
(which formerly exited using stop()), the test harness Verilog generator
(since it is no longer necessary), and the DRAM model (since it is no
longer connected). However, this should substantially reduce the effort
of building test harnesses in the future, since manual or semi-automatic
Verilog writing should no longer be necessary. Furthermore, there is now
very little duplication of effort between the Verilator and VCS test
harnesses.
This commit removes support for DRAMsim, which is a bit of an unfortunate
consequence. The main blocker is the lack of Verilog parameterization for
BlackBox. It would be straightforward to revive DRAMsim once support for
that feature is added to Chisel and FIRRTL. But that might not even be
necessary, as we move towards synthesizable DRAM models and FAME-1
transformations.
Until recently, we were assuming that the data channel in AXI was always
right-justified. However, for narrow writes, the data must actually be
aligned within the byte lanes. This commit changes some of the
converters in order to fix this issue.
There was a bug in the L2 cache in which a merged get request was
causing the tracker to read the old data from the data array,
overwriting the updated data acquired from outer memory. Changed it so
that pending_reads is no longer set if the data in the buffer is already
valid.
There was a bug in the PortedTileLinkCrossbar. The new GrantFromSrc and
FinishToDst types used client_id for routing to managers. This caused
bits to get cut off, which meant the Finish messages could not be routed
correctly. Changed to use manager_id instead.
We used to just be writing the SCR anyway, but now that the SCR maps are
automatically defined VCS will detect the missing SCR and bail out when
compiling test harness code. This patch just doesn't write the HTIF SCR when
there isn't one.
We're building a chip with 8 memory channels. Since this will require a
complicated test setup we want to also be able to bring up the chip with fewer
memory channels. This commit adds a SCR that controls the number of active
memory channels on a chip. Toggling this SCR will scramble memory and drop
Nasti messages, so it's only possible to change while the chip is booting.
By default this just adds a 1-bit SCR, which essentially no extra logic.
When multiple memory channel configurations are enabled at elaboration time, a
NastiMemoryInterconnect is generated for each channel configuration. The
number of outstanding misses is increased to coorespond to the maximum number
of banks per memory channel (added as a parameter), which I believe is
necessary to avoid deadlock in the memory system.
A configuration is added that supports 8 memory channels but has only 1 enabled
by default.
This uses the new SCRFile changes to generate a header file containing a list
of all the SCRs in a core to remove the magic constant "63" (the HTIF clock
divider control register) and replace it with a generated number (which is
still 63).
- Useful for taking Rocket's out-of-order writebacks and generating an
in-order commit log.
- Resulting commit log can be diffed against Spike's commit log.
