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"),
}