start bitcoin core private blockchain

[victorkimba17]

To start a customised private bitcoin core blockchain, all i need to do is:

1) change the genesis block
2) change the timestamp of genesis block

is there anything else?

[1715285494]

1715285494

[1715285494]

1715285494

[QRC]

To start a customised private bitcoin core blockchain, all i need to do is:

1) change the genesis block
2) change the timestamp of genesis block

is there anything else?

what do you mean by private bitcoin core chain?
1) bitcoin core it's just a client, so use bitcoin blockchain term.
2) do you want to fork bitcoin codebase? In this case you have to change more parameters than genesis block: port number, magic message number ect.
3) But if you just want to run private bitcoin blockchain for your own testing or something similar, you don't have to change anything just start daemon with -regtest option.

[victorkimba17]

what do you mean by private bitcoin core chain?
1) bitcoin core it's just a client, so use bitcoin blockchain term.
2) do you want to fork bitcoin codebase? In this case you have to change more parameters than genesis block: port number, magic message number ect.
3) But if you just want to run private bitcoin blockchain for your own testing or something similar, you don't have to change anything just start daemon with -regtest option.

Thank you. I would like to fork bitcoin code base.

In src/chainparams.cpp

    const char* pszTimestamp = "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks";
    const CScript genesisOutputScript = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3 8c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;

Can i just change the timestamp and genesis output script, to create a customised bitcoin ?

[QRC]

what do you mean by private bitcoin core chain?
1) bitcoin core it's just a client, so use bitcoin blockchain term.
2) do you want to fork bitcoin codebase? In this case you have to change more parameters than genesis block: port number, magic message number ect.
3) But if you just want to run private bitcoin blockchain for your own testing or something similar, you don't have to change anything just start daemon with -regtest option.

Thank you. I would like to fork bitcoin code base.

In src/chainparams.cpp

    const char* pszTimestamp = "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks";
    const CScript genesisOutputScript = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3 8c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;

Can i just change the timestamp and genesis output script, to create a customised bitcoin ?

No it's not enough.
Read some guide, for example this one:
Complete Guide on How to Create a New Alt Coin

[victorkimba17]

i found a good link
https://bitcoin.stackexchange.com/questions/13122/scriptsig-coinbase-structure-of-the-genesis-block

i tried to print out the value in chainparams.cpp before assert in line 125. But value is printed out as 0x0,  and 0x103?

fprintf(stdout,"0x%x\n",consensus.hashGenesisBlock);
fprintf(stdout,"0x%x\n",genesis.hashMerkleRoot);

the warning is : format specifies type 'unsigned int' but the argument has type 'uint256'

Update: use this to print uint256. They are string.

fprintf(stdout,"%s\n", consensus.hashGenesisBlock.ToString().c_str());
fprintf(stdout,"%s\n",genesis.hashMerkleRoot.ToString().c_str());

[victorkimba17]

No it's not enough.
Read some guide, for example this one:
Complete Guide on How to Create a New Alt Coin

I read it.

[victorkimba17]

i only changed the timestamp, when starting bitcoind, i got the error in debug.log

2018-05-24 07:50:44 mapAddressBook.size() = 1
2018-05-24 07:50:44 ERROR: ReadBlockFromDisk: Errors in block header at CBlockDiskPos(nFile=0, nPos=8)
2018-05-24 07:50:44 *** Failed to read block
2018-05-24 07:50:44 Error: Error: A fatal internal error occurred, see debug.log for details

It is solved by running bitcoind with -reindex

[victorkimba17]

when i run the bitcoin-cli, i got the error

error code: -28
error message:
Loading wallet...

In the protocol.h, the error meaning is:

RPC_IN_WARMUP                   = -28, //!< Client still warming up