Set Fulu fork epochs for Holesky, Hoodi, and Sepolia testnets (#15721)

* Set Fulu fork epochs for Holesky, Hoodi, and Sepolia testnets

* Update commits

* Add fulu.yaml to the presets file path loader

* Add the following placeholder fields:
- CELLS_PER_EXT_BLOB
- FIELD_ELEMENTS_PER_CELL
- FIELD_ELEMENTS_PER_EXT_BLOB
- KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH

---------

Co-authored-by: Preston Van Loon <preston@pvl.dev>

config/params/loader_test.go

@@ -30,6 +30,7 @@ var placeholderFields = []string{
 	"ATTESTATION_DUE_BPS",
 	"ATTESTATION_DUE_BPS_GLOAS",
 	"BLOB_SIDECAR_SUBNET_COUNT_FULU",
+	"CELLS_PER_EXT_BLOB",
 	"CONTRIBUTION_DUE_BPS",
 	"CONTRIBUTION_DUE_BPS_GLOAS",
 	"EIP6110_FORK_EPOCH",
@@ -45,10 +46,13 @@ var placeholderFields = []string{
 	"EIP7928_FORK_EPOCH",
 	"EIP7928_FORK_VERSION",
 	"EPOCHS_PER_SHUFFLING_PHASE",
+	"FIELD_ELEMENTS_PER_CELL",     // Configured as a constant in config/fieldparams/mainnet.go
+	"FIELD_ELEMENTS_PER_EXT_BLOB", // Configured in proto/ssz_proto_library.bzl
 	"GLOAS_FORK_EPOCH",
 	"GLOAS_FORK_VERSION",
 	"INCLUSION_LIST_SUBMISSION_DEADLINE",
 	"INCLUSION_LIST_SUBMISSION_DUE_BPS",
+	"KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH", // Configured in proto/ssz_proto_library.bzl
 	"MAX_BYTES_PER_INCLUSION_LIST",
 	"MAX_REQUEST_BLOB_SIDECARS_FULU",
 	"MAX_REQUEST_INCLUSION_LIST",
@@ -388,6 +392,7 @@ func presetsFilePath(t *testing.T, config string) []string {
 		path.Join(fPath, "presets", config, "capella.yaml"),
 		path.Join(fPath, "presets", config, "deneb.yaml"),
 		path.Join(fPath, "presets", config, "electra.yaml"),
+		path.Join(fPath, "presets", config, "fulu.yaml"),
 	}
 }
 

config/params/testnet_holesky_config.go

@@ -1,7 +1,5 @@
 package params
 
-import "math"
-
 // UseHoleskyNetworkConfig uses the Holesky beacon chain specific network config.
 func UseHoleskyNetworkConfig() {
 	cfg := BeaconNetworkConfig().Copy()
@@ -41,12 +39,21 @@ func HoleskyConfig() *BeaconChainConfig {
 	cfg.DenebForkVersion = []byte{0x05, 0x1, 0x70, 0x0}
 	cfg.ElectraForkEpoch = 115968 // Mon, Feb 24 at 21:55:12 UTC
 	cfg.ElectraForkVersion = []byte{0x06, 0x1, 0x70, 0x0}
-	cfg.FuluForkEpoch = math.MaxUint64
-	cfg.FuluForkVersion = []byte{0x07, 0x1, 0x70, 0x0} // TODO: Define holesky fork version for fulu. This is a placeholder value.
+	cfg.FuluForkEpoch = 165120 // 2025-10-01 08:48:00 UTC
+	cfg.FuluForkVersion = []byte{0x07, 0x1, 0x70, 0x0}
 	cfg.TerminalTotalDifficulty = "0"
 	cfg.DepositContractAddress = "0x4242424242424242424242424242424242424242"
 	cfg.EjectionBalance = 28000000000
-	cfg.BlobSchedule = []BlobScheduleEntry{}
+	cfg.BlobSchedule = []BlobScheduleEntry{
+		{
+			MaxBlobsPerBlock: 15,
+			Epoch:            166400, // 2025-10-07 01:20:00 UTC
+		},
+		{
+			MaxBlobsPerBlock: 21,
+			Epoch:            167936, // 2025-10-13 21:10:24 UTC
+		},
+	}
 	cfg.InitializeForkSchedule()
 	return cfg
 }

config/params/testnet_hoodi_config.go

@@ -1,9 +1,5 @@
 package params
 
-import (
-	"math"
-)
-
 // UseHoodiNetworkConfig uses the Hoodi beacon chain specific network config.
 func UseHoodiNetworkConfig() {
 	cfg := BeaconNetworkConfig().Copy()
@@ -49,11 +45,20 @@ func HoodiConfig() *BeaconChainConfig {
 	cfg.DenebForkVersion = []byte{0x50, 0x00, 0x09, 0x10}
 	cfg.ElectraForkEpoch = 2048
 	cfg.ElectraForkVersion = []byte{0x60, 0x00, 0x09, 0x10}
-	cfg.FuluForkEpoch = math.MaxUint64
+	cfg.FuluForkEpoch = 50688 // 2025-10-28 18:53:12 UTC
 	cfg.FuluForkVersion = []byte{0x70, 0x00, 0x09, 0x10}
 	cfg.TerminalTotalDifficulty = "0"
 	cfg.DepositContractAddress = "0x00000000219ab540356cBB839Cbe05303d7705Fa"
-	cfg.BlobSchedule = []BlobScheduleEntry{}
+	cfg.BlobSchedule = []BlobScheduleEntry{
+		{
+			MaxBlobsPerBlock: 15,
+			Epoch:            52480, // 2025-11-05 18:02:00 UTC
+		},
+		{
+			MaxBlobsPerBlock: 21,
+			Epoch:            54016, // 2025-11-12 13:52:24 UTC
+		},
+	}
 	cfg.DefaultBuilderGasLimit = uint64(60000000)
 	cfg.InitializeForkSchedule()
 	return cfg

config/params/testnet_sepolia_config.go

@@ -1,8 +1,6 @@
 package params
 
 import (
-	"math"
-
 	eth1Params "github.com/ethereum/go-ethereum/params"
 )
 
@@ -46,12 +44,21 @@ func SepoliaConfig() *BeaconChainConfig {
 	cfg.DenebForkVersion = []byte{0x90, 0x00, 0x00, 0x73}
 	cfg.ElectraForkEpoch = 222464 // Wed, Mar 5 at 07:29:36 UTC
 	cfg.ElectraForkVersion = []byte{0x90, 0x00, 0x00, 0x74}
-	cfg.FuluForkEpoch = math.MaxUint64
-	cfg.FuluForkVersion = []byte{0x90, 0x00, 0x00, 0x75} // TODO: Define sepolia fork version for fulu. This is a placeholder value.
+	cfg.FuluForkEpoch = 272640 // 2025-10-14 07:36:00 UTC
+	cfg.FuluForkVersion = []byte{0x90, 0x00, 0x00, 0x75}
 	cfg.TerminalTotalDifficulty = "17000000000000000"
 	cfg.DepositContractAddress = "0x7f02C3E3c98b133055B8B348B2Ac625669Ed295D"
 	cfg.DefaultBuilderGasLimit = uint64(60000000)
-	cfg.BlobSchedule = []BlobScheduleEntry{}
+	cfg.BlobSchedule = []BlobScheduleEntry{
+		{
+			MaxBlobsPerBlock: 15,
+			Epoch:            274176, // 2025-10-21 03:26:24 UTC
+		},
+		{
+			MaxBlobsPerBlock: 21,
+			Epoch:            275712, // 2025-10-27 23:16:48 UTC
+		},
+	}
 	cfg.InitializeForkSchedule()
 	return cfg
 }