core: implement BLOBBASEFEE opcode (0x4a) (#28098)

Implements "EIP-7516: BLOBBASEFEE opcode" for cancun, as per spec: https://eips.ethereum.org/EIPS/eip-7516

core/vm/eips.go

@@ -282,9 +282,15 @@ func opBlobHash(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([
 	return nil, nil
 }
 
-// enable4844 applies EIP-4844 (DATAHASH opcode)
+// opBlobBaseFee implements BLOBBASEFEE opcode
+func opBlobBaseFee(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
+	blobBaseFee, _ := uint256.FromBig(interpreter.evm.Context.BlobBaseFee)
+	scope.Stack.push(blobBaseFee)
+	return nil, nil
+}
+
+// enable4844 applies EIP-4844 (BLOBHASH opcode)
 func enable4844(jt *JumpTable) {
-	// New opcode
 	jt[BLOBHASH] = &operation{
 		execute:     opBlobHash,
 		constantGas: GasFastestStep,
@@ -293,6 +299,16 @@ func enable4844(jt *JumpTable) {
 	}
 }
 
+// enable7516 applies EIP-7516 (BLOBBASEFEE opcode)
+func enable7516(jt *JumpTable) {
+	jt[BLOBBASEFEE] = &operation{
+		execute:     opBlobBaseFee,
+		constantGas: GasQuickStep,
+		minStack:    minStack(0, 1),
+		maxStack:    maxStack(0, 1),
+	}
+}
+
 // enable6780 applies EIP-6780 (deactivate SELFDESTRUCT)
 func enable6780(jt *JumpTable) {
 	jt[SELFDESTRUCT] = &operation{

core/vm/evm.go

@@ -67,14 +67,14 @@ type BlockContext struct {
 	GetHash GetHashFunc
 
 	// Block information
-	Coinbase      common.Address // Provides information for COINBASE
-	GasLimit      uint64         // Provides information for GASLIMIT
-	BlockNumber   *big.Int       // Provides information for NUMBER
-	Time          uint64         // Provides information for TIME
-	Difficulty    *big.Int       // Provides information for DIFFICULTY
-	BaseFee       *big.Int       // Provides information for BASEFEE
-	Random        *common.Hash   // Provides information for PREVRANDAO
-	ExcessBlobGas *uint64        // ExcessBlobGas field in the header, needed to compute the data
+	Coinbase    common.Address // Provides information for COINBASE
+	GasLimit    uint64         // Provides information for GASLIMIT
+	BlockNumber *big.Int       // Provides information for NUMBER
+	Time        uint64         // Provides information for TIME
+	Difficulty  *big.Int       // Provides information for DIFFICULTY
+	BaseFee     *big.Int       // Provides information for BASEFEE
+	BlobBaseFee *big.Int       // Provides information for BLOBBASEFEE
+	Random      *common.Hash   // Provides information for PREVRANDAO
 }
 
 // TxContext provides the EVM with information about a transaction.

core/vm/jump_table.go

@@ -82,7 +82,8 @@ func validate(jt JumpTable) JumpTable {
 
 func newCancunInstructionSet() JumpTable {
 	instructionSet := newShanghaiInstructionSet()
-	enable4844(&instructionSet) // EIP-4844 (DATAHASH opcode)
+	enable4844(&instructionSet) // EIP-4844 (BLOBHASH opcode)
+	enable7516(&instructionSet) // EIP-7516 (BLOBBASEFEE opcode)
 	enable1153(&instructionSet) // EIP-1153 "Transient Storage"
 	enable5656(&instructionSet) // EIP-5656 (MCOPY opcode)
 	enable6780(&instructionSet) // EIP-6780 SELFDESTRUCT only in same transaction

core/vm/opcodes.go

@@ -101,6 +101,7 @@ const (
 	SELFBALANCE OpCode = 0x47
 	BASEFEE     OpCode = 0x48
 	BLOBHASH    OpCode = 0x49
+	BLOBBASEFEE OpCode = 0x4a
 )
 
 // 0x50 range - 'storage' and execution.
@@ -287,6 +288,7 @@ var opCodeToString = map[OpCode]string{
 	SELFBALANCE: "SELFBALANCE",
 	BASEFEE:     "BASEFEE",
 	BLOBHASH:    "BLOBHASH",
+	BLOBBASEFEE: "BLOBBASEFEE",
 
 	// 0x50 range - 'storage' and execution.
 	POP:      "POP",
@@ -444,6 +446,7 @@ var stringToOp = map[string]OpCode{
 	"CHAINID":        CHAINID,
 	"BASEFEE":        BASEFEE,
 	"BLOBHASH":       BLOBHASH,
+	"BLOBBASEFEE":    BLOBBASEFEE,
 	"DELEGATECALL":   DELEGATECALL,
 	"STATICCALL":     STATICCALL,
 	"CODESIZE":       CODESIZE,

core/vm/runtime/env.go

@@ -37,6 +37,7 @@ func NewEnv(cfg *Config) *vm.EVM {
 		Difficulty:  cfg.Difficulty,
 		GasLimit:    cfg.GasLimit,
 		BaseFee:     cfg.BaseFee,
+		BlobBaseFee: cfg.BlobBaseFee,
 		Random:      cfg.Random,
 	}
 

core/vm/runtime/runtime.go

@@ -44,6 +44,7 @@ type Config struct {
 	Debug       bool
 	EVMConfig   vm.Config
 	BaseFee     *big.Int
+	BlobBaseFee *big.Int
 	BlobHashes  []common.Hash
 	Random      *common.Hash
 
@@ -95,6 +96,9 @@ func setDefaults(cfg *Config) {
 	if cfg.BaseFee == nil {
 		cfg.BaseFee = big.NewInt(params.InitialBaseFee)
 	}
+	if cfg.BlobBaseFee == nil {
+		cfg.BlobBaseFee = new(big.Int)
+	}
 }
 
 // Execute executes the code using the input as call data during the execution.