Function sol_poseidon 

pub unsafe fn sol_poseidon(
    parameters: u64,
    endianness: u64,
    vals: *const u8,
    val_len: u64,
    hash_result: *mut u8,
) -> u64

Compute a Poseidon hash using Solana’s runtime syscall.

Returns the Solana runtime status code (0 on success).

Safety

vals must point to a valid array of slice descriptors and hash_result must point to 32 writable output bytes.