Verilator v5 #102
Verilator v5 #102
Conversation
|
This looks brilliant, thanks Greg! I'll quickly change the GitHub actions to do simulator builds in the nix sandbox, so we don't have to keep updating the dependencies. |
Thanks I've just added a commit to this PR to do just that but as you know nix better than me let's see what you propose as well! |
|
Thanks @HU90m, any thoughts on how to make it use the lowRISC cache? It spends the first few minutes building python dependencies |
|
This should work for now: nix build --accept-flake-config .#sonata-simulatorIt would be nice to get the See #102 (comment) for a better solution. |
sw/cheri/sim_boot_stub/makefile
Outdated
| @@ -0,0 +1,9 @@ | |||
| CFLAGS=-target riscv32-unknown-unknown -mcpu=cheriot -mabi=cheriot \ | |||
There was a problem hiding this comment.
It'll be good that this uses cmake similar to other binaries that we have, but we can save that to a later PR.
There was a problem hiding this comment.
It uses make intentionally so you can build it in environments where you don't have cmake just to minimize dependencies required to build it
flake.nix
Outdated
| buildPhase = '' | ||
| HOME=$TMPDIR fusesoc --cores-root=. run \ | ||
| --target=sim --tool=verilator --setup \ | ||
| --build lowrisc:sonata:system \ | ||
| --verilator_options="+define+RVFI -j $NIX_BUILD_CORES" \ | ||
| --make_options="-j $NIX_BUILD_CORES" | ||
| --make_options="-j $NIX_BUILD_CORES" && | ||
| make -C sw/cheri/sim_boot_stub/ |
There was a problem hiding this comment.
We probably should put the sim stub building in another derivation.
There was a problem hiding this comment.
I had a similar thought, but I'm happy for this to go in for now. In a follow up PR, we can transition to CMake and create derivations for the software builds.
There was a problem hiding this comment.
I did actually do it that way initially, then switched it over to this as it felt like it's something you should distribute with the simulator
There was a problem hiding this comment.
What could be done is to build it in a separate derivation, and then copy it to $out/share for the simulator.
There was a problem hiding this comment.
Turns out we need to do this to get the osx build to work. CHERIoT LLVM clashes with the system LLVM and the verilated C++ fails to build so will make that change.
| sudo apt install verilator libelf-dev | ||
| pip install -r python-requirements.txt | ||
| - name: Install Nix | ||
| uses: cachix/install-nix-action@v24 |
There was a problem hiding this comment.
To enable cache globally for all nix commands, you can do something similar to https://github.com/lowRISC/lowrisc-nix/blob/34f1d472d6066a42c684416f5e9e755d25ec6270/.github/workflows/ci.yml#L52-L54 here.
| lint_off -rule UNOPTFLAT -file "*/rtl/prim_subreg_ext.sv" | ||
| lint_off -rule BLKSEQ -file "*/rtl/ibex_tracer.sv" | ||
|
|
||
| // Bug seem in Verilator v5.020 where trace chandles produces a C++ compliation |
There was a problem hiding this comment.
nit: handles, compilation
With this fixed direct elf loading works properly
Previously C++11 was requested in the verilator arguments. Pinning to a specific C++ version is no longer required and verilator v5 generated code requires C++14 features.
The stub just immediately jumps to the start address for programs loaded via the flash bootloader. It allows programs built to be started via the flash bootloader to run unmodified on the simulator.
|
@HU90m happy to approve this now? |
|
You force pushed over my documentation change, I've made a follow up PR here: #105 |
I'd like this working for the hackathon so if you've got more major changes you'd like following review I'd appreciate it if we could just record it in an issue for now and get this merged.