This is useful for certain cross-compilation workloads, and to cache
rarely changing build products.
To use this functionality, build e.g. as follows:
cmake . -B build-export -DEXPORT_BBA_FILES=../bba-files -DARCH=all
cmake --build build-export -t nextpnr-all-bba
cmake . -B build-import -DIMPORT_BBA_FILES=../bba-files -DARCH=all
cmake --build build-import
Two user-visible changes were made:
* `-DUSE_RUST` is replaced with `-DBUILD_RUST`, by analogy with
`-DBUILD_PYTHON`
* `-DCOVERAGE` was removed as it doesn't work with either modern GCC
or Clang
This removes the atomic rename for bbasm outputs because it embeds
the resulting paths into the `.cc` files in embed mode. In any case
the write should be fast enough to not be a big risk for interrupted
builds.
This was tested with Clang 19 only (gcc hasn't had a release that
supports `#embed` yet).
While it served a purpose (granting the ability to build `.bba` files
separately from the rest of nextpnr), it made things excessively
convoluted, especially around paths.
This commit removes the ability to pre-generate chip databases. As far
as I know, I was the primary user of that feature. It can be added back
if there is demand for it.
In exchange the per-family `CMakeLists.txt` files are now much easier
to understand.
Currently a segfault happens when the DI port is not specified. Leaving
it unconnected is probably incorrect, but it shouldn't crash the placer.
Fix by adding a check.
Each DSP block contains two slices, and each slice contains multiple
MULT18X18D and ALU54B units. Each unit configures each register to use
any of CLK0/1/2/3, CE0/1/2/3, and RST0/1/2/3 ports, and the ports are
connected per unit (so for example, two MULTs in the same block could
connect their CLK0s to different external signals). However, the
hardware only has one actual port per block, so it's required that
all CLK0 signals within a block are the same.
Because the packer is in general allowed to combine two unrelated units
into one block, it may end up combining units that use different signals
for the same port, which would eventually have caused a router failure.
This commit adds validity checks which ensure only unique signals are
used per block, and adds remapping so that conflicting signals are
automatically reassigned when possible and required.
