Calculating Genesis Block

chainparams.cpp

// ... snip ...

#include <arith_uint256.h>

// ... snip ...

class CMainParams : public CChainParams {
public:
    CMainParams() {

        // ... snip ...

        genesis = CreateGenesisBlock(1534567890, 0, 0x1d00ffff, 1, 50 * COIN);

        consensus.hashGenesisBlock = uint256S("0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
        if (true && (genesis.GetHash() != consensus.hashGenesisBlock)) {
            std::cout << std::string("Begin calculating Mainnet Genesis Block:\n");
            arith_uint256 hashTarget = arith_uint256().SetCompact(genesis.nBits);
            uint256 hash;
            genesis.nNonce = 0;
            while (UintToArith256(genesis.GetHash()) > hashTarget) {
                ++genesis.nNonce;
                if (genesis.nNonce == 0) {
                    std::cout << std::string("NONCE WRAPPED, incrementing time:\n");
                    ++genesis.nTime;
                }
                if (genesis.nNonce % 1000 == 0) {
                    std::cout << strNetworkID << " nonce: " << genesis.nNonce << " time: " << genesis.nTime << " hash: " << genesis.GetHash().ToString().c_str() << "\n";
                }
            }
            std::cout << "Mainnet ---\n";
            std::cout << "  nonce: " << genesis.nNonce <<  "\n";
            std::cout << "   time: " << genesis.nTime << "\n";
            std::cout << "   hash: " << genesis.GetHash().ToString().c_str() << "\n";
            std::cout << "   merklehash: "  << genesis.hashMerkleRoot.ToString().c_str() << "\n";
            std::cout << std::string("Finished calculating Mainnet Genesis Block:\n");
        }

        consensus.hashGenesisBlock = genesis.GetHash();

        // ... snip ...

}

// ... snip ...

Exactly what I needed. Couldn't find a python tool for a custom new hash, and this snippet did the job. Thanks.

you are my hero ;-))