How do I generate a TrustedCheckpoint(CHT) on my private chain?

Question

I saw this link, but still don't know how to get CHTRoot and BloomRoot, only know that SectionHead is block[(SectionIndex+1)*32768-1].headhash

https://github.com/ethereum/devp2p/blob/master/caps/les.md#gethelpertrieproofs-0x11

ex:

// MainnetTrustedCheckpoint contains the light client trusted checkpoint for the main network.
MainnetTrustedCheckpoint = &TrustedCheckpoint{
    Name:         "mainnet",
    SectionIndex: 227,
    SectionHead:  common.HexToHash("0xa2e0b25d72c2fc6e35a7f853cdacb193b4b4f95c606accf7f8fa8415283582c7"),
    CHTRoot:      common.HexToHash("0xf69bdd4053b95b61a27b106a0e86103d791edd8574950dc96aa351ab9b9f1aa0"),
    BloomRoot:    common.HexToHash("0xec1b454d4c6322c78ccedf76ac922a8698c3cac4d98748a84af4995b7bd3d744"),
}

Answer 1

set Command Line Options:--lightserv value --lightpeers value

than it will Automatic update SectionIndex and printf Storing CHT ,Storing bloom trie

the client just set:--syncmode=light