Add genesis settings section

specs/merge/beacon-chain.md

@@ -12,6 +12,8 @@
 - [Custom types](#custom-types)
 - [Constants](#constants)
   - [Execution](#execution)
+- [Configuration](#configuration)
+  - [Genesis settings](#genesis-settings)
 - [Containers](#containers)
   - [Extended containers](#extended-containers)
     - [`BeaconBlockBody`](#beaconblockbody)
@@ -66,6 +68,17 @@ This patch adds transaction execution to the beacon chain as part of the Merge f
 | `BASE_FEE_MAX_CHANGE_DENOMINATOR` | `uint64(2**3)` (= 8) |
 | `ELASTICITY_MULTIPLIER` | `uint64(2**1)` (= 2) |
 
+## Configuration
+
+### Genesis settings
+
+*Note*: These configuration settings do not apply to the mainnet and are utilized only by pure Merge testing.
+
+| Name | Value |
+| - | - |
+| `GENESIS_GAS_LIMIT` | `uint64(30000000)` (= 30,000,000) |
+| `GENESIS_BASE_FEE_PER_GAS` | `uint64(1000000000)` (= 1,000,000,000) |
+
 ## Containers
 
 ### Extended containers
@@ -380,7 +393,8 @@ def initialize_beacon_state_from_eth1(eth1_block_hash: Bytes32,
     state.latest_execution_payload_header.block_hash = eth1_block_hash
     state.latest_execution_payload_header.timestamp = eth1_timestamp
     state.latest_execution_payload_header.random = eth1_block_hash
-    state.latest_execution_payload_header.gas_limit = MIN_GAS_LIMIT
+    state.latest_execution_payload_header.gas_limit = GENESIS_GAS_LIMIT
+    state.latest_execution_payload_header.base_fee_per_gas = GENESIS_BASE_FEE_PER_GAS
 
     return state
 ```

tests/core/pyspec/eth2spec/test/helpers/execution_payload.py

@@ -17,14 +17,14 @@ def build_empty_execution_payload(spec, state, randao_mix=None):
         logs_bloom=spec.ByteVector[spec.BYTES_PER_LOGS_BLOOM](),  # TODO: zeroed logs bloom for empty logs ok?
         block_number=latest.block_number + 1,
         random=randao_mix,
-        gas_limit=max(latest.gas_limit, spec.MIN_GAS_LIMIT),
+        gas_limit=latest.gas_limit,  # retain same limit
         gas_used=0,  # empty block, 0 gas
         timestamp=timestamp,
         base_fee_per_gas=spec.uint64(0),
         block_hash=spec.Hash32(),
         transactions=empty_txs,
     )
-    payload.base_fee_per_gas = spec.compute_base_fee_per_gas(latest, payload)
+    payload.base_fee_per_gas = spec.compute_base_fee_per_gas(payload, latest)
     # TODO: real RLP + block hash logic would be nice, requires RLP and keccak256 dependency however.
     payload.block_hash = spec.Hash32(spec.hash(payload.hash_tree_root() + b"FAKE RLP HASH"))
 

tests/core/pyspec/eth2spec/test/helpers/genesis.py

@@ -78,6 +78,7 @@ def create_genesis_state(spec, validator_balances, activation_threshold):
         # Initialize the execution payload header (with block number and genesis time set to 0)
         state.latest_execution_payload_header.block_hash = eth1_block_hash
         state.latest_execution_payload_header.random = eth1_block_hash
-        state.latest_execution_payload_header.gas_limit = spec.MIN_GAS_LIMIT
+        state.latest_execution_payload_header.gas_limit = spec.GENESIS_GAS_LIMIT
+        state.latest_execution_payload_header.base_fee_per_gas = spec.GENESIS_BASE_FEE_PER_GAS
 
     return state