Merge branch 'master' into fix/delete-node-sister-not-resolved

.gitignore

-node_modules
\ No newline at end of file
+node_modules
+artifacts
+cache

CHALLENGE

-Two oracles:
-Implement as three MIPS instructions
+One oracle:
+Implement as a MIPS instruction?
 
-InputOracle -- Preagreed upon inputs
+InputOracle -- Preagreed upon inputs (TODO: replace with memory reads from given address range)
   $a0 = input choice
-    0 -- StateRoot(n)
+    0 -- BlockHash(n)
     1 -- Transactions(n+1)
     2 -- Coinbase(n+1)
     3 -- Uncles(n+1)
@@ -24,31 +24,36 @@ PreimageOracle -- key value store
   returns
   $v0 = preimage[$t7...$t0] >> ($a0 * 32)
 
-Program returns a hash in [$t7...$t0] and exits(special instruction) with the hash in the state
+Program returns a hash in [$t7...$t0] and exits(jump to 0xDEAD0000) with the hash in the state
 
 Challenge Flow:
 C is challenger, D is defender
 Super nice, the defender barely needs to spend gas!
 
-C: InitiateChallenge(bytes blockHeaderN, bytes blockHeaderNp1,
+C: InitiateChallenge(uint blockNumberN, bytes blockHeaderN, bytes blockHeaderNp1,
                      bytes32 assertionHash, bytes32 finalSystemHash, string[] assertionProof, uint256 stepCount)
   * checks hashes of the block headers
   * saves inputs for input oracle
   * confirms assertionHash != blockHeaderNp1.Hash
-  * expectCorrect = (assertionHash == blockHeaderNp1.Hash)
-  * confirm assertionProof proves the final state of [$t7...$t0] in finalSystemHash is assertionHash
-  * confirm assertionProof proves the final state of *$pc in finalSystemHash is special exit instruction
-  * L = 0, R = stepCount-1   # we agree at L=0, we disagree at R=stepCount
+  * confirm assertionProof[0..7] proves the final state of [$t7...$t0] in finalSystemHash is assertionHash
+  * confirm assertionProof[8] proves the final state of $pc in finalSystemHash is 0xDEAD0000
+  * L = 0, R = stepCount   # we agree at L=0, we disagree at R=stepCount
   * return new challengeId
-  * assertedRiscState[0] = GlobalStartSystemHash
-  * assertedRiscState[stepCount-1] = finalSystemHash
-C: ProposeRiscState(uint256 challengeId, uint256 riscState)
+  * assertedState[0] = GlobalStartSystemHash + inputOracleMutations
+  * defendedState[0] = GlobalStartSystemHash + inputOracleMutations
+  * assertedState[stepCount] = finalSystemHash
+........
+if it's one step, we are done. considering it's not, we binary search
+........
+C: ProposeState(uint256 challengeId, uint256 riscState)
   * stepNumber = GetStepNumber(uint256 challengeId) returns floor((L + R) / 2)
-  * assert assertedRiscState[stepNumber] == 0
-  * assertedRiscState[stepNumber] = riscState
-D: RespondRiscState(uint256 challengeId, bool yes) onlyOwner
+  * assert assertedState[stepNumber] == 0
+  * assertedState[stepNumber] = riscState
+D: RespondState(uint256 challengeId, uint256 riscState) onlyOwner
   * off-chain: run to step = stepNumber, get state hash, check if it matches
-  * if yes:
+  * stepNumber = GetStepNumber(uint256 challengeId) returns floor((L + R) / 2)
+  * defendedState[stepNumber] = riscState
+  * if assertedState[stepNumber] == defendedState[stepNumber]:
       L = stepNumber     # we agree at stepNumber
     else:
       R = stepNumber     # we disagree at stepNumber
@@ -56,16 +61,27 @@ D: RespondRiscState(uint256 challengeId, bool yes) onlyOwner
 ........
 binary search until L+1 == R
 the issue is with the L->R transition
-aka assertedRiscState[L] -> assertedRiscState[R]
+aka assertedState[L] -> assertedState[R]
 ........
 # call this at any time (global), adds them to a preimage lookup for PreimageOracle
-C: ProposePreimage(bytes anything)
+# put these on the MIPS contract
+C: AddPreimage(bytes anything)
   * preimageLookup[keccak256(anything)] = anything
-C: ConfirmStateTransition(uint256 challengeId, ustrings proofs)
+C: AddMerkleState(uint256 stateHash, uint32 addr, uint32 value, string proof)
+  * validate proof in assertedState[stepNumber]
+  * riscMemory[stepNumber][address] = value
+
+* Final
+C: ConfirmStateTransition(uint256 challengeId)
   * assert L+1 == R
-  * validate all proofs in assertedRiscState[L]
   * do the state transition
-  * if any needed pieces of start state are missing, challenge fails (it can try again)
-  * reconstruct the riscState after transition -> newRiscState 
-  * assert assertedRiscState[R] == newRiscState
+  * if any needed pieces of start state are missing in riscMemory, challenge fails (it can try again)
+  * reconstruct the riscState after transition -> newState 
+  * assert assertedState[R] == newState
   * pay out bounty
+
+# optional claim for the defender
+# prove the defendedState[L] -> defendedState[R]
+# NOTE, if it's the last step, defendedState[R] might not exist. 
+
+TODO: ensure the state merklization is canonical. if it doesn't match perfectly you can lose
\ No newline at end of file

README.md

@@ -21,6 +21,14 @@ The system is checking an embedded block in CI now
 * TODO: Get initial block info / txs with oracle
 * TODO: Stub all syscalls after it's "booted"
 
+## TODO
+
+* Make minigeth use the 0xD0000000 input oracle / add input oracle to risc/run.py. See [contracts/Challenge.sol](https://github.com/geohot/cannon/blob/master/contracts/Challenge.sol)
+* Add blocks / tx trie to the preimage oracle [see issue](https://github.com/geohot/cannon/issues/2)
+* Finish and test the MIPS state transition function in contracts/MIPS.sol
+* Get minigeth running in Solidity MIPS emulator with reasonable performance (Go code using EVM with native memory)
+* Add merkleization for MIPS ReadMemory and WriteMemory
+
 ## Usage
 ```
 # verify the transition from 13284469 -> 13284470

contracts/Challenge.sol

+// SPDX-License-Identifier: MIT
+pragma solidity ^0.7.3;
+
+import "./lib/Lib_RLPReader.sol";
+
+interface IMIPS {
+  function Step(bytes32 stateHash) external view returns (bytes32);
+  function ReadMemory(bytes32 stateHash, uint32 addr) external view returns (uint32);
+  function ReadBytes32(bytes32 stateHash, uint32 addr) external view returns (bytes32);
+  function WriteMemory(bytes32 stateHash, uint32 addr, uint32 val) external pure returns (bytes32);
+}
+
+contract Challenge {
+  address payable immutable owner;
+
+  // the mips machine state transition function
+  IMIPS immutable mips;
+
+  // the program start state
+  bytes32 immutable GlobalStartState;
+
+  struct Chal {
+    uint256 L;
+    uint256 R;
+    mapping(uint256 => bytes32) assertedState;
+    mapping(uint256 => bytes32) defendedState;
+    address payable challenger;
+  }
+  mapping(uint256 => Chal) challenges;
+
+  constructor(IMIPS imips, bytes32 globalStartState) {
+    owner = msg.sender;
+    mips = imips;
+    GlobalStartState = globalStartState;
+  }
+
+  // allow getting money (and withdrawing the bounty, honor system)
+  fallback() external payable {}
+  receive() external payable {}
+  function withdraw() external {
+    require(msg.sender == owner);
+    owner.transfer(address(this).balance);
+  }
+
+  // memory helpers
+
+  function writeBytes32(bytes32 stateHash, uint32 addr, bytes32 val) internal view returns (bytes32) {
+    for (uint32 i = 0; i < 32; i += 4) {
+      uint256 tv = uint256(val>>(224-(i*8)));
+
+      stateHash = mips.WriteMemory(stateHash, addr+i, uint32(tv));
+    }
+    return stateHash;
+  }
+
+  // create challenge
+  uint256 public lastChallengeId = 0;
+
+  function newChallengeTrusted(bytes32 startState, bytes32 finalSystemState, uint256 stepCount) internal returns (uint256) {
+    uint256 challengeId = lastChallengeId;
+    Chal storage c = challenges[challengeId];
+    lastChallengeId += 1;
+
+    // the challenger arrives
+    c.challenger = msg.sender;
+
+    // the state is set 
+    c.assertedState[0] = startState;
+    c.defendedState[0] = startState;
+    c.assertedState[stepCount] = finalSystemState;
+
+    // init the binary search
+    c.L = 0;
+    c.R = stepCount;
+
+    // find me later
+    return challengeId;
+  }
+
+  function InitiateChallenge(uint blockNumberN, bytes calldata blockHeaderNp1,
+        bytes32 assertionRoot, bytes32 finalSystemState, uint256 stepCount) external returns (uint256) {
+    require(blockhash(blockNumberN+1) == keccak256(blockHeaderNp1), "end block hash wrong");
+
+    // decode the blocks
+    Lib_RLPReader.RLPItem[] memory blockNp1 = Lib_RLPReader.readList(blockHeaderNp1);
+    bytes32 parentHash = Lib_RLPReader.readBytes32(blockNp1[0]);
+    require(blockhash(blockNumberN) == parentHash, "parent block hash somehow wrong");
+
+    bytes32 newroot = Lib_RLPReader.readBytes32(blockNp1[3]);
+    require(assertionRoot != newroot, "asserting that the real state is correct is not a challenge");
+
+    // load starting info into the input oracle
+    // we both agree at the beginning
+    // the first instruction executed in MIPS should be an access of startState
+    // parentblockhash, txhash, coinbase, unclehash, gaslimit
+    bytes32 startState = GlobalStartState;
+    startState = writeBytes32(startState, 0xD0000000, parentHash);
+    startState = writeBytes32(startState, 0xD0000020, Lib_RLPReader.readBytes32(blockNp1[4]));
+    startState = writeBytes32(startState, 0xD0000040, bytes32(uint256(Lib_RLPReader.readAddress(blockNp1[2]))));
+    startState = writeBytes32(startState, 0xD0000060, Lib_RLPReader.readBytes32(blockNp1[1]));
+    startState = writeBytes32(startState, 0xD0000080, bytes32(Lib_RLPReader.readUint256(blockNp1[9])));
+
+    // confirm the finalSystemHash asserts the state you claim (in $t0-$t7) and the machine is stopped
+    // you must load these proofs into MIPS before calling this
+    // we disagree at the end
+    require(mips.ReadBytes32(finalSystemState, 0xC0000020) == assertionRoot, "you are claiming a different state root in machine");
+    require(mips.ReadMemory(finalSystemState, 0xC0000080) == 0xDEAD0000, "machine is not stopped in final state (PC == 0xDEAD0000)");
+
+    return newChallengeTrusted(startState, finalSystemState, stepCount);
+  }
+
+  // binary search
+
+  function getStepNumber(uint256 challengeId) view public returns (uint256) {
+    Chal storage c = challenges[challengeId];
+    require(c.challenger != address(0), "invalid challenge");
+    return (c.L+c.R)/2;
+  }
+
+  function ProposeState(uint256 challengeId, bytes32 riscState) external {
+    Chal storage c = challenges[challengeId];
+    require(c.challenger != address(0), "invalid challenge");
+    require(c.challenger == msg.sender, "must be challenger");
+
+    uint256 stepNumber = getStepNumber(challengeId);
+    require(c.assertedState[stepNumber] == bytes32(0), "state already proposed");
+    c.assertedState[stepNumber] = riscState;
+  }
+
+  function RespondState(uint256 challengeId, bytes32 riscState) external {
+    Chal storage c = challenges[challengeId];
+    require(c.challenger != address(0), "invalid challenge");
+    require(owner == msg.sender, "must be owner");
+
+    uint256 stepNumber = getStepNumber(challengeId);
+    require(c.assertedState[stepNumber] != bytes32(0), "challenger state not proposed");
+    require(c.defendedState[stepNumber] == bytes32(0), "state already proposed");
+    // technically, we don't have to save these states
+    // but if we want to prove us right and not just the attacker wrong, we do
+    c.defendedState[stepNumber] = riscState;
+    if (c.assertedState[stepNumber] == c.defendedState[stepNumber]) {
+      // agree
+      c.L = stepNumber;
+    } else {
+      // disagree
+      c.R = stepNumber;
+    }
+  }
+
+  // final payout
+
+  event ChallengerWins(uint256 challengeId);
+  event ChallengerLoses(uint256 challengeId);
+
+  function ConfirmStateTransition(uint256 challengeId) external {
+    Chal storage c = challenges[challengeId];
+    require(c.challenger != address(0), "invalid challenge");
+    require(c.challenger == msg.sender, "must be challenger");
+    require(c.L + 1 == c.R, "binary search not finished");
+
+    require(mips.Step(c.assertedState[c.L]) == c.assertedState[c.R], "wrong asserted state");
+
+    // pay out bounty!!
+    c.challenger.transfer(address(this).balance);
+    
+    emit ChallengerWins(challengeId);
+  }
+
+  function MockChallengerStateTransition(uint256 challengeId, bytes32 finalRiscState) external {
+    Chal storage c = challenges[challengeId];
+    require(c.challenger != address(0), "invalid challenge");
+    require(owner == msg.sender, "must be owner");
+    require(c.L + 1 == c.R, "binary search not finished");
+
+    // it's 0 if you agree with all attacker states except the final one
+    // in which case, you get a free pass to submit now
+    require(c.defendedState[c.R] == finalRiscState || c.defendedState[c.R] == bytes32(0), "must be consistent with state");
+
+    require(mips.Step(c.defendedState[c.L]) == finalRiscState, "wrong asserted state");
+
+    // consider the challenger mocked
+    // if they staked a bounty, you could claim it here
+    emit ChallengerLoses(challengeId);
+  }
+}

contracts/MIPS.sol

+// SPDX-License-Identifier: MIT
+pragma solidity ^0.7.3;
+
+// https://inst.eecs.berkeley.edu/~cs61c/resources/MIPS_Green_Sheet.pdf
+// https://uweb.engr.arizona.edu/~ece369/Resources/spim/MIPSReference.pdf
+
+// This is a separate contract from the challenge contract
+// Anyone can use it to validate a MIPS state transition
+// First, to prepare, you call AddMerkleState, which adds valid state nodes in the stateHash. 
+// If you are using the Preimage oracle, you call AddPreimage
+// Then, you call Step. Step will revert if state is missing. If all state is present, it will return the next hash
+
+contract MIPS {
+  // This state is global
+  mapping(bytes32 => mapping (uint32 => uint64)) public state;
+  mapping(bytes32 => bytes) public preimage;
+
+  function AddPreimage(bytes calldata anything) public {
+    preimage[keccak256(anything)] = anything;
+  }
+
+  function AddMerkleState(bytes32 stateHash, uint32 addr, uint32 value, string calldata proof) public {
+    // TODO: check proof
+    state[stateHash][addr] = (1 << 32) | value;
+  }
+
+  uint32 constant public REG_OFFSET = 0xc0000000;
+  uint32 constant public REG_PC = REG_OFFSET + 0x20*4;
+
+  function WriteMemory(bytes32 stateHash, uint32 addr, uint32 val) public pure returns (bytes32) {
+    // TODO: does the stateHash mutation
+    require(addr & 3 == 0, "write memory must be 32-bit aligned");
+  }
+
+  // needed for preimage oracle
+  function ReadBytes32(bytes32 stateHash, uint32 addr) public view returns (bytes32) {
+    uint256 ret = 0;
+    for (uint32 i = 0; i < 32; i += 4) {
+      ret <<= 32;
+      ret |= uint256(ReadMemory(stateHash, addr+i));
+    }
+    return bytes32(ret);
+  }
+
+  function ReadMemory(bytes32 stateHash, uint32 addr) public view returns (uint32) {
+    if (addr == REG_OFFSET) {
+      // zero register is always 0
+      return 0;
+    }
+    require(addr & 3 == 0, "read memory must be 32-bit aligned");
+    uint64 ret = state[stateHash][addr];
+    require((ret >> 32) == 1, "memory was not initialized");
+    return uint32(ret);
+  }
+
+  // compute the next state
+  // will revert if any required input state is missing
+  function Step(bytes32 stateHash) public view returns (bytes32) {
+    // instruction fetch
+    uint32 pc = ReadMemory(stateHash, REG_PC);
+    uint32 insn = ReadMemory(stateHash, pc);
+    uint32 opcode = insn >> 26; // 6-bits
+
+    // decode
+
+    // register fetch
+    uint32 rs;
+    uint32 rt;
+    if (opcode != 2 && opcode != 3) {   // J-type: j and jal have no register fetch
+      // R-type or I-type (stores rt)
+      rs = ReadMemory(stateHash, REG_OFFSET + ((insn >> 19) & 0x7C));
+      if (opcode == 0) {
+        // R-type (stores rd)
+        rt = ReadMemory(stateHash, REG_OFFSET + ((insn >> 14) & 0x7C));
+      }
+    }
+
+    // memory fetch (all I-type)
+    // we do the load for stores also
+    uint32 mem;
+    if (opcode >= 0x20) {
+      // M[R[rs]+SignExtImm]
+      uint32 SignExtImm = insn&0xFFFF | (insn&0x8000 != 0 ? 0xFFFF0000 : 0);
+      mem = ReadMemory(stateHash, (rs + SignExtImm) & 0xFFFFFFFC);
+    }
+
+    // execute
+    execute(insn, rs, rt, mem);
+
+    // write back
+
+  }
+
+  // TODO: move pure testable stuff to LibMIPS.sol
+  function execute(uint32 insn, uint32 rs, uint32 rt, uint32 mem) public pure returns (uint32) {
+    uint32 opcode = insn >> 26;    // 6-bits
+    uint32 func = insn & 0x3f; // 6-bits
+    // TODO: deref the immed into a register
+    if (opcode == 0) {
+      uint32 shamt = (insn >> 6) & 0x1f;
+      // R-type (ArithLog)
+      if (func == 0x20 || func == 0x21) { return rs+rt;   // add or addu
+      } else if (func == 0x24) { return rs&rt;            // and
+      } else if (func == 0x27) { return ~(rs|rt);         // nor
+      } else if (func == 0x25) { return (rs|rt);          // or
+      } else if (func == 0x22 || func == 0x23) {
+        return rs-rt;   // sub or subu
+      } else if (func == 0x2a) {
+        return int32(rs)<int32(rt) ? 1 : 0; // slt
+      } else if (func == 0x26) {
+        return rs<rt ? 1 : 0;            // sltu
+      // Shift and ShiftV
+      } else if (func == 0x00) { return rt << shamt;      // sll
+      } else if (func == 0x04) { return rt << rs;         // sllv
+      } else if (func == 0x03) { return rt >> shamt;      // sra
+      } else if (func == 0x07) { return rt >> rs;         // srav
+      } else if (func == 0x02) { return rt >> shamt;      // srl
+      } else if (func == 0x06) { return rt >> rs;         // srlv
+      }
+    } else if (func == 0x20) { return mem;   // lb
+    } else if (func == 0x24) { return mem;   // lbu
+    } else if (func == 0x21) { return mem;   // lh
+    } else if (func == 0x25) { return mem;   // lhu
+    } else if (func == 0x23) { return mem;   // lw
+    } else if (func&0x3c == 0x28) { return rt;  // sb, sh, sw
+    }
+  }
+
+}

hardhat.config.js

+/**
+ * @type import('hardhat/config').HardhatUserConfig
+ */
+module.exports = {
+  solidity: "0.7.3",
+};

minigeth/consensus/ethash/fake_ethash.go

@@ -101,7 +101,7 @@ func (ethash *Ethash) Finalize(chain consensus.ChainHeaderReader, header *types.
 	// Accumulate any block and uncle rewards and commit the final state root
 	accumulateRewards(chain.Config(), state, header, uncles)
 	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
-	//fmt.Println("new Root", header.Root)
+	fmt.Println("new Root", header.Root)
 }
 
 func (ethash *Ethash) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {

minigeth/consensus/misc/eip1559.go

+// Copyright 2021 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package misc
+
+import (
+	"fmt"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+// VerifyEip1559Header verifies some header attributes which were changed in EIP-1559,
+// - gas limit check
+// - basefee check
+func VerifyEip1559Header(config *params.ChainConfig, parent, header *types.Header) error {
+	// Verify that the gas limit remains within allowed bounds
+	parentGasLimit := parent.GasLimit
+	if !config.IsLondon(parent.Number) {
+		parentGasLimit = parent.GasLimit * params.ElasticityMultiplier
+	}
+	if err := VerifyGaslimit(parentGasLimit, header.GasLimit); err != nil {
+		return err
+	}
+	// Verify the header is not malformed
+	if header.BaseFee == nil {
+		return fmt.Errorf("header is missing baseFee")
+	}
+	// Verify the baseFee is correct based on the parent header.
+	expectedBaseFee := CalcBaseFee(config, parent)
+	if header.BaseFee.Cmp(expectedBaseFee) != 0 {
+		return fmt.Errorf("invalid baseFee: have %s, want %s, parentBaseFee %s, parentGasUsed %d",
+			expectedBaseFee, header.BaseFee, parent.BaseFee, parent.GasUsed)
+	}
+	return nil
+}
+
+// CalcBaseFee calculates the basefee of the header.
+func CalcBaseFee(config *params.ChainConfig, parent *types.Header) *big.Int {
+	// If the current block is the first EIP-1559 block, return the InitialBaseFee.
+	if !config.IsLondon(parent.Number) {
+		return new(big.Int).SetUint64(params.InitialBaseFee)
+	}
+
+	var (
+		parentGasTarget          = parent.GasLimit / params.ElasticityMultiplier
+		parentGasTargetBig       = new(big.Int).SetUint64(parentGasTarget)
+		baseFeeChangeDenominator = new(big.Int).SetUint64(params.BaseFeeChangeDenominator)
+	)
+	// If the parent gasUsed is the same as the target, the baseFee remains unchanged.
+	if parent.GasUsed == parentGasTarget {
+		return new(big.Int).Set(parent.BaseFee)
+	}
+	if parent.GasUsed > parentGasTarget {
+		// If the parent block used more gas than its target, the baseFee should increase.
+		gasUsedDelta := new(big.Int).SetUint64(parent.GasUsed - parentGasTarget)
+		x := new(big.Int).Mul(parent.BaseFee, gasUsedDelta)
+		y := x.Div(x, parentGasTargetBig)
+		baseFeeDelta := math.BigMax(
+			x.Div(y, baseFeeChangeDenominator),
+			common.Big1,
+		)
+
+		return x.Add(parent.BaseFee, baseFeeDelta)
+	} else {
+		// Otherwise if the parent block used less gas than its target, the baseFee should decrease.
+		gasUsedDelta := new(big.Int).SetUint64(parentGasTarget - parent.GasUsed)
+		x := new(big.Int).Mul(parent.BaseFee, gasUsedDelta)
+		y := x.Div(x, parentGasTargetBig)
+		baseFeeDelta := x.Div(y, baseFeeChangeDenominator)
+
+		return math.BigMax(
+			x.Sub(parent.BaseFee, baseFeeDelta),
+			common.Big0,
+		)
+	}
+}

minigeth/consensus/misc/gaslimit.go

+// Copyright 2021 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package misc
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/params"
+)
+
+// VerifyGaslimit verifies the header gas limit according increase/decrease
+// in relation to the parent gas limit.
+func VerifyGaslimit(parentGasLimit, headerGasLimit uint64) error {
+	// Verify that the gas limit remains within allowed bounds
+	diff := int64(parentGasLimit) - int64(headerGasLimit)
+	if diff < 0 {
+		diff *= -1
+	}
+	limit := parentGasLimit / params.GasLimitBoundDivisor
+	if uint64(diff) >= limit {
+		return fmt.Errorf("invalid gas limit: have %d, want %d +-= %d", headerGasLimit, parentGasLimit, limit-1)
+	}
+	if headerGasLimit < params.MinGasLimit {
+		return errors.New("invalid gas limit below 5000")
+	}
+	return nil
+}

minigeth/main.go

@@ -2,14 +2,19 @@ package main
 
 import (
 	"fmt"
+	"log"
+	"math/big"
 	"os"
 	"strconv"
 
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus/misc"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/oracle"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
@@ -24,29 +29,33 @@ func main() {
 
 	blockNumber, _ := strconv.Atoi(os.Args[1])
 
-	// read header
-	var header types.Header
-	{
-		f, _ := os.Open(fmt.Sprintf("data/block_%d", blockNumber))
-		rlpheader := rlp.NewStream(f, 0)
-		rlpheader.Decode(&header)
-		f.Close()
-		fmt.Println("read old block")
+	// non mips
+	oracle.PrefetchBlock(big.NewInt(int64(blockNumber)), true, trie.NewStackTrie(nil))
+	oracle.PrefetchBlock(big.NewInt(int64(blockNumber)+1), false, trie.NewStackTrie(nil))
+
+	// read start block header
+	var parent types.Header
+	rlperr := rlp.DecodeBytes(oracle.Preimage(oracle.Input(0)), &parent)
+	if rlperr != nil {
+		log.Fatal(rlperr)
 	}
 
 	// read header
 	var newheader types.Header
-	{
-		f, _ := os.Open(fmt.Sprintf("data/block_%d", blockNumber+1))
-		rlpheader := rlp.NewStream(f, 0)
-		rlpheader.Decode(&newheader)
-		f.Close()
-		fmt.Println("read new block")
-	}
+	// from parent
+	newheader.ParentHash = parent.Hash()
+	newheader.Number = big.NewInt(0).Add(parent.Number, big.NewInt(1))
+	newheader.BaseFee = misc.CalcBaseFee(params.MainnetChainConfig, &parent)
+
+	// from input oracle
+	newheader.TxHash = oracle.Input(1)
+	newheader.Coinbase = common.BigToAddress(oracle.Input(2).Big())
+	newheader.UncleHash = oracle.Input(3)
+	newheader.GasLimit = oracle.Input(4).Big().Uint64()
 
 	bc := core.NewBlockChain()
-	database := state.NewDatabase(header)
-	statedb, _ := state.New(header.Root, database, nil)
+	database := state.NewDatabase(parent)
+	statedb, _ := state.New(parent.Root, database, nil)
 	vmconfig := vm.Config{}
 	processor := core.NewStateProcessor(params.MainnetChainConfig, bc, bc.Engine())
 	fmt.Println("made state processor")
@@ -64,23 +73,23 @@ func main() {
 	var uncles []*types.Header
 	var receipts []*types.Receipt
 	block := types.NewBlock(&newheader, txs, uncles, receipts, trie.NewStackTrie(nil))
-	fmt.Println("made block, parent:", header.ParentHash)
+	fmt.Println("made block, parent:", newheader.ParentHash)
 
 	// if this is correct, the trie is working
 	// TODO: it's the previous block now
 	if newheader.TxHash != block.Header().TxHash {
 		panic("wrong transactions for block")
 	}
+	if newheader.UncleHash != block.Header().UncleHash {
+		panic("wrong uncles for block")
+	}
 
 	_, _, _, err := processor.Process(block, statedb, vmconfig)
 	if err != nil {
-		panic("processor error")
+		log.Fatal(err)
 	}
+	newroot := statedb.IntermediateRoot(bc.Config().IsEIP158(newheader.Number))
 
-	fmt.Println("process done with hash", header.Root, "->", block.Header().Root, "real", newheader.Root)
-	if block.Header().Root == newheader.Root {
-		fmt.Println("good transition")
-	} else {
-		panic("BAD transition :((")
-	}
+	fmt.Println("process done with hash", parent.Root, "->", newroot)
+	oracle.Output(newroot)
 }

minigeth/oracle/apitypes.go

+//go:build !mips
+// +build !mips
+
+package oracle
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+// SendTxArgs represents the arguments to submit a transaction
+// This struct is identical to ethapi.TransactionArgs, except for the usage of
+// common.MixedcaseAddress in From and To
+type SendTxArgs struct {
+	From                 common.MixedcaseAddress  `json:"from"`
+	To                   *common.MixedcaseAddress `json:"to"`
+	Gas                  hexutil.Uint64           `json:"gas"`
+	GasPrice             *hexutil.Big             `json:"gasPrice"`
+	MaxFeePerGas         *hexutil.Big             `json:"maxFeePerGas"`
+	MaxPriorityFeePerGas *hexutil.Big             `json:"maxPriorityFeePerGas"`
+	Value                hexutil.Big              `json:"value"`
+	Nonce                hexutil.Uint64           `json:"nonce"`
+
+	// We accept "data" and "input" for backwards-compatibility reasons.
+	// "input" is the newer name and should be preferred by clients.
+	// Issue detail: https://github.com/ethereum/go-ethereum/issues/15628
+	Data  *hexutil.Bytes `json:"data"`
+	Input *hexutil.Bytes `json:"input,omitempty"`
+
+	// For non-legacy transactions
+	AccessList *types.AccessList `json:"accessList,omitempty"`
+	ChainID    *hexutil.Big      `json:"chainId,omitempty"`
+}
+
+type Header struct {
+	ParentHash  *common.Hash      `json:"parentHash"       gencodec:"required"`
+	UncleHash   *common.Hash      `json:"sha3Uncles"       gencodec:"required"`
+	Coinbase    *common.Address   `json:"miner"            gencodec:"required"`
+	Root        *common.Hash      `json:"stateRoot"        gencodec:"required"`
+	TxHash      *common.Hash      `json:"transactionsRoot" gencodec:"required"`
+	ReceiptHash *common.Hash      `json:"receiptsRoot"     gencodec:"required"`
+	Bloom       *types.Bloom      `json:"logsBloom"        gencodec:"required"`
+	Difficulty  *hexutil.Big      `json:"difficulty"       gencodec:"required"`
+	Number      *hexutil.Big      `json:"number"           gencodec:"required"`
+	GasLimit    *hexutil.Uint64   `json:"gasLimit"         gencodec:"required"`
+	GasUsed     *hexutil.Uint64   `json:"gasUsed"          gencodec:"required"`
+	Time        *hexutil.Uint64   `json:"timestamp"        gencodec:"required"`
+	Extra       *hexutil.Bytes    `json:"extraData"        gencodec:"required"`
+	MixDigest   *common.Hash      `json:"mixHash"`
+	Nonce       *types.BlockNonce `json:"nonce"`
+	BaseFee     *hexutil.Big      `json:"baseFeePerGas" rlp:"optional"`
+	// transactions
+	Transactions []SendTxArgs `json:"transactions"`
+}
+
+func (dec *Header) ToHeader() types.Header {
+	var h types.Header
+	h.ParentHash = *dec.ParentHash
+	h.UncleHash = *dec.UncleHash
+	h.Coinbase = *dec.Coinbase
+	h.Root = *dec.Root
+	h.TxHash = *dec.TxHash
+	h.ReceiptHash = *dec.ReceiptHash
+	h.Bloom = *dec.Bloom
+	h.Difficulty = (*big.Int)(dec.Difficulty)
+	h.Number = (*big.Int)(dec.Number)
+	h.GasLimit = uint64(*dec.GasLimit)
+	h.GasUsed = uint64(*dec.GasUsed)
+	h.Time = uint64(*dec.Time)
+	h.Extra = *dec.Extra
+	if dec.MixDigest != nil {
+		h.MixDigest = *dec.MixDigest
+	}
+	if dec.Nonce != nil {
+		h.Nonce = *dec.Nonce
+	}
+	if dec.BaseFee != nil {
+		h.BaseFee = (*big.Int)(dec.BaseFee)
+	}
+	return h
+}
+
+// ToTransaction converts the arguments to a transaction.
+func (args *SendTxArgs) ToTransaction() *types.Transaction {
+	// Add the To-field, if specified
+	var to *common.Address
+	if args.To != nil {
+		dstAddr := args.To.Address()
+		to = &dstAddr
+	}
+
+	var input []byte
+	if args.Input != nil {
+		input = *args.Input
+	} else if args.Data != nil {
+		input = *args.Data
+	}
+
+	var data types.TxData
+	switch {
+	case args.MaxFeePerGas != nil:
+		al := types.AccessList{}
+		if args.AccessList != nil {
+			al = *args.AccessList
+		}
+		data = &types.DynamicFeeTx{
+			To:         to,
+			ChainID:    (*big.Int)(args.ChainID),
+			Nonce:      uint64(args.Nonce),
+			Gas:        uint64(args.Gas),
+			GasFeeCap:  (*big.Int)(args.MaxFeePerGas),
+			GasTipCap:  (*big.Int)(args.MaxPriorityFeePerGas),
+			Value:      (*big.Int)(&args.Value),
+			Data:       input,
+			AccessList: al,
+		}
+	case args.AccessList != nil:
+		data = &types.AccessListTx{
+			To:         to,
+			ChainID:    (*big.Int)(args.ChainID),
+			Nonce:      uint64(args.Nonce),
+			Gas:        uint64(args.Gas),
+			GasPrice:   (*big.Int)(args.GasPrice),
+			Value:      (*big.Int)(&args.Value),
+			Data:       input,
+			AccessList: *args.AccessList,
+		}
+	default:
+		data = &types.LegacyTx{
+			To:       to,
+			Nonce:    uint64(args.Nonce),
+			Gas:      uint64(args.Gas),
+			GasPrice: (*big.Int)(args.GasPrice),
+			Value:    (*big.Int)(&args.Value),
+			Data:     input,
+		}
+	}
+	return types.NewTx(data)
+}

minigeth/oracle/embedded_mips.go

@@ -8,12 +8,47 @@ import (
 	"io/ioutil"
 	"math/big"
 	"os"
+	"strconv"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
 var preimages = make(map[common.Hash][]byte)
+var inputs [6]common.Hash
+var inputsLoaded bool = false
+
+func Input(index int) common.Hash {
+	if index < 0 || index > 5 {
+		panic("bad input index")
+	}
+	if !inputsLoaded {
+		blockNumber, _ := strconv.Atoi(os.Args[1])
+		f, err := os.Open(fmt.Sprintf("/tmp/eth/%d", blockNumber))
+		if err != nil {
+			panic("missing inputs")
+		}
+		defer f.Close()
+		ret, err := ioutil.ReadAll(f)
+
+		for i := 0; i < len(inputs); i++ {
+			inputs[i] = common.BytesToHash(ret[i*0x20 : i*0x20+0x20])
+		}
+
+		inputsLoaded = true
+	}
+	return inputs[index]
+}
+
+func Output(output common.Hash) {
+	if output == inputs[5] {
+		fmt.Println("good transition")
+	} else {
+		fmt.Println(output, "!=", inputs[5])
+		panic("BAD transition :((")
+	}
+}
 
 func Preimage(hash common.Hash) []byte {
 	val, ok := preimages[hash]
@@ -43,4 +78,5 @@ func Preimage(hash common.Hash) []byte {
 // these are stubs in embedded world
 func PrefetchStorage(*big.Int, common.Address, common.Hash, func(map[common.Hash][]byte)) {}
 func PrefetchAccount(*big.Int, common.Address, func(map[common.Hash][]byte))              {}
-func PrefetchCode(*big.Int, common.Hash)                                                  {}
+func PrefetchCode(blockNumber *big.Int, addrHash common.Hash)                      {}
+func PrefetchBlock(blockNumber *big.Int, startBlock bool, hasher types.TrieHasher) {}

minigeth/oracle/prefetch.go

@@ -16,7 +16,9 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/rlp"
 )
 
 type jsonreq struct {
@@ -38,6 +40,12 @@ type jsonresps struct {
 	Result  string `json:"result"`
 }
 
+type jsonrespt struct {
+	Jsonrpc string `json:"jsonrpc"`
+	Id      uint64 `json:"id"`
+	Result  Header `json:"result"`
+}
+
 // Result structs for GetProof
 type AccountResult struct {
 	Address      common.Address  `json:"address"`
@@ -169,8 +177,85 @@ func PrefetchCode(blockNumber *big.Int, addrHash common.Hash) {
 	preimages[hash] = ret
 }
 
-func PrefetchBlock(blockNumber *big.Int) {
-	// TODO: Write this.
+var inputs [6]common.Hash
+
+func Input(index int) common.Hash {
+	if index < 0 || index > 5 {
+		panic("bad input index")
+	}
+	return inputs[index]
+}
+
+func Output(output common.Hash) {
+	if output == inputs[5] {
+		fmt.Println("good transition")
+	} else {
+		fmt.Println(output, "!=", inputs[5])
+		panic("BAD transition :((")
+	}
+}
+
+func PrefetchBlock(blockNumber *big.Int, startBlock bool, hasher types.TrieHasher) {
+	r := jsonreq{Jsonrpc: "2.0", Method: "eth_getBlockByNumber", Id: 1}
+	r.Params = make([]interface{}, 2)
+	r.Params[0] = fmt.Sprintf("0x%x", blockNumber.Int64())
+	r.Params[1] = true
+	jsonData, _ := json.Marshal(r)
+
+	/*dat, _ := ioutil.ReadAll(getAPI(jsonData))
+	fmt.Println(string(dat))*/
+
+	jr := jsonrespt{}
+	err := json.NewDecoder(getAPI(jsonData)).Decode(&jr)
+	if err != nil {
+		panic("bad block prefetch")
+	}
+	//fmt.Println(jr.Result)
+	blockHeader := jr.Result.ToHeader()
+
+	// put in the start block header
+	if startBlock {
+		blockHeaderRlp, _ := rlp.EncodeToBytes(blockHeader)
+		hash := crypto.Keccak256Hash(blockHeaderRlp)
+		preimages[hash] = blockHeaderRlp
+		inputs[0] = hash
+		return
+	}
+
+	// second block
+	if blockHeader.ParentHash != Input(0) {
+		fmt.Println(blockHeader.ParentHash, Input(0))
+		panic("block transition isn't correct")
+	}
+	inputs[1] = blockHeader.TxHash
+	inputs[2] = blockHeader.Coinbase.Hash()
+	inputs[3] = blockHeader.UncleHash
+	inputs[4] = common.BigToHash(big.NewInt(int64(blockHeader.GasLimit)))
+
+	// secret input
+	inputs[5] = blockHeader.Root
+
+	// save the inputs
+	saveinput := make([]byte, 0)
+	for i := 0; i < len(inputs); i++ {
+		saveinput = append(saveinput, inputs[i].Bytes()[:]...)
+	}
+	key := fmt.Sprintf("/tmp/eth/%d", blockNumber.Uint64()-1)
+	ioutil.WriteFile(key, saveinput, 0644)
+
+	txs := make([]*types.Transaction, len(jr.Result.Transactions))
+	for i := 0; i < len(jr.Result.Transactions); i++ {
+		txs[i] = jr.Result.Transactions[i].ToTransaction()
+	}
+
+	// put in transaction trie
+
+	//return blockHeader, txs
+
+	/*var uncles []*types.Header
+	var receipts []*types.Receipt
+	block := types.NewBlock(&blockHeader, txs, uncles, receipts, trie.NewStackTrie(nil))*/
+
 }
 
 func getProofAccount(blockNumber *big.Int, addr common.Address, skey common.Hash, storage bool) []string {

package.json

@@ -2,6 +2,7 @@
   "dependencies": {
     "@types/node": "^16.9.2",
     "ethers": "^5.4.7",
+    "hardhat": "^2.6.4",
     "rlp": "^2.2.6",
     "typescript": "^4.4.3"
   }

risc/run.py

@@ -286,7 +286,7 @@ mu.mem_write(SIZE-0x2000, struct.pack(">IIIIIIIII",
   _AT_PAGESZ, 0x1000, 0)) # auxv
 
 # block
-mu.mem_write(SIZE-0x800, b"13284491\x00")
+mu.mem_write(SIZE-0x800, b"13284469\x00")
 #mu.mem_write(SIZE-0x800, b"13284469\x00")
 
 mu.mem_write(SIZE-0x400, b"GOGC=off\x00")