# EPF Week 14 Update

This week I opened the main [PR](https://github.com/grandinetech/grandine/pull/385) and I also got the SHA-256 precompile [PR](https://github.com/grandinetech/universal-precompiles/pull/1) merged. I have another [PR](https://github.com/grandinetech/universal-precompiles/pull/2) pending for review which is the `bls12_381` precompile. For initial testing, I was instructed by Artiom to run all the grandine tests with my implementation of the `bls12_381` precompile to check and see if anything is broken. I ran the following command from the grandine root directory after updating the git submodules for the `consensus-spec-tests` and fetching the git LFS files. All the tests passed successfully.

cargo test --release --workspace --exclude zkvm_host --exclude zkvm_guest_risc0 --no-default-features --feature zkcrypto

One issue I faced while running the zkVMs was that it panicked at runtime. Then I found out that this line was causing the error.

let state = match phase {
    Some(phase) => BeaconState::<P>::from_ssz_at_phase(phase, &state_ssz)?,
    None => BeaconState::<P>::from_ssz(&config, &state_ssz)?,
};

This error emerged from the function `read_list` in `ssz/src/shared.rs` and this could be easily mitigated by skipping the following check, but as was mentioned by Artiom, it is not a good approach. Likely, the issue is that the maximum variable's value is 0 because it gets corrupted before it is sent to the function parameter so it always returns an error. I will look into this more and figure out what exactly went wrong.

if actual > maximum {
    return Err(ReadError::ListTooLong { maximum, actual });
}

## Resources

- [SHA-256 precompile PR](https://github.com/grandinetech/universal-precompiles/pull/1)
- [`bls12_381` precompile PR](https://github.com/grandinetech/universal-precompiles/pull/2)

## Conclusion

Apart from these, there isn't any other update from my side since my exams just ended in the past week and immediately after we have this festival in Kolkata called Durga Puja. I wish to be more productive in the upcoming weeks and get the project completed and polished.