From 98b5e5be51640b65c073a6dc2372c28a40a41604 Mon Sep 17 00:00:00 2001
From: Linda Guiga <101227802+LindaGuiga@users.noreply.github.com>
Date: Wed, 22 Nov 2023 13:30:52 -0500
Subject: [PATCH] Initialize blockhashes (#1370)

* Initialize blockhashes

* Update comment
---
 evm/src/fixed_recursive_verifier.rs | 23 +++++++++++++++++++++--
 evm/src/proof.rs                    |  3 ++-
 evm/tests/empty_txn_list.rs         |  6 ++++--
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/evm/src/fixed_recursive_verifier.rs b/evm/src/fixed_recursive_verifier.rs
index 9f3ec06c..9628e5fc 100644
--- a/evm/src/fixed_recursive_verifier.rs
+++ b/evm/src/fixed_recursive_verifier.rs
@@ -1033,9 +1033,10 @@ where
             block_inputs
                 .set_proof_with_pis_target(&self.block.parent_block_proof, parent_block_proof);
         } else {
-            // Initialize genesis_state_trie, state_root_after and the block number for correct connection between blocks.
+            // Initialize genesis_state_trie, state_root_after, block hashes and the block number for correct connection between blocks.
             // Initialize `state_root_after`.
-            let state_trie_root_after_keys = 24..32;
+            let state_trie_root_after_keys =
+                TrieRootsTarget::SIZE..TrieRootsTarget::SIZE + TrieRootsTarget::HASH_SIZE;
             let mut nonzero_pis = HashMap::new();
             for (key, &value) in state_trie_root_after_keys
                 .zip_eq(&h256_limbs::<F>(public_values.trie_roots_before.state_root))
@@ -1057,6 +1058,24 @@ where
                 nonzero_pis.insert(key, value);
             }
 
+            // Initialize block hashes.
+            let block_hashes_keys = TrieRootsTarget::SIZE * 2 + BlockMetadataTarget::SIZE
+                ..TrieRootsTarget::SIZE * 2
+                    + BlockMetadataTarget::SIZE
+                    + BlockHashesTarget::BLOCK_HASHES_SIZE
+                    - 8;
+
+            for i in 0..public_values.block_hashes.prev_hashes.len() - 1 {
+                let targets = h256_limbs::<F>(public_values.block_hashes.prev_hashes[i]);
+                for j in 0..8 {
+                    nonzero_pis.insert(block_hashes_keys.start + 8 * (i + 1) + j, targets[j]);
+                }
+            }
+            let cur_targets = h256_limbs::<F>(public_values.block_hashes.prev_hashes[255]);
+            for i in 0..8 {
+                nonzero_pis.insert(block_hashes_keys.end + i, cur_targets[i]);
+            }
+
             // Initialize the block number.
             let block_number_key = TrieRootsTarget::SIZE * 2 + 6;
             nonzero_pis.insert(block_number_key, F::NEG_ONE);
diff --git a/evm/src/proof.rs b/evm/src/proof.rs
index ea8507b1..f5e4dc6a 100644
--- a/evm/src/proof.rs
+++ b/evm/src/proof.rs
@@ -385,7 +385,8 @@ pub(crate) struct TrieRootsTarget {
 
 impl TrieRootsTarget {
     /// Number of `Target`s required for all trie hashes.
-    pub(crate) const SIZE: usize = 24;
+    pub(crate) const HASH_SIZE: usize = 8;
+    pub(crate) const SIZE: usize = Self::HASH_SIZE * 3;
 
     /// Extracts trie hash `Target`s for all tries from the provided public input `Target`s.
     /// The provided `pis` should start with the trie hashes.
diff --git a/evm/tests/empty_txn_list.rs b/evm/tests/empty_txn_list.rs
index 0285286d..eaa9c0cb 100644
--- a/evm/tests/empty_txn_list.rs
+++ b/evm/tests/empty_txn_list.rs
@@ -4,7 +4,7 @@ use std::time::Duration;
 
 use env_logger::{try_init_from_env, Env, DEFAULT_FILTER_ENV};
 use eth_trie_utils::partial_trie::{HashedPartialTrie, PartialTrie};
-use ethereum_types::H256;
+use ethereum_types::{BigEndianHash, H256};
 use keccak_hash::keccak;
 use log::info;
 use plonky2::field::goldilocks_field::GoldilocksField;
@@ -47,6 +47,8 @@ fn test_empty_txn_list() -> anyhow::Result<()> {
         transactions_root: transactions_trie.hash(),
         receipts_root: receipts_trie.hash(),
     };
+    let mut initial_block_hashes = vec![H256::default(); 256];
+    initial_block_hashes[255] = H256::from_uint(&0x200.into());
     let inputs = GenerationInputs {
         signed_txn: None,
         withdrawals: vec![],
@@ -66,7 +68,7 @@ fn test_empty_txn_list() -> anyhow::Result<()> {
         block_bloom_before: [0.into(); 8],
         block_bloom_after: [0.into(); 8],
         block_hashes: BlockHashes {
-            prev_hashes: vec![H256::default(); 256],
+            prev_hashes: initial_block_hashes,
             cur_hash: H256::default(),
         },
         addresses: vec![],