comments: add comments to clarify flags and byte codes (bnb-chain#1245)

core/systemcontracts/upgrade.go

@@ -52,6 +52,12 @@ var (
 )
 
 func init() {
+
+	// For contract upgrades, the following information is from `bsc-genesis-contract`, to be specifically,
+	// 1) `CommitUrl` is the specific git commit, based on which the byte code is compiled from;
+	// 2) `Code` is the byte code of the contract, which is generated by compiling `bsc-genesis-contract`.
+	// You can refer to `https://github.com/bnb-chain/bsc-genesis-contract` to compile the smart contracts and do the verification.
+
 	ramanujanUpgrade[rialtoNet] = &Upgrade{
 		UpgradeName: "ramanujan",
 		Configs: []*UpgradeConfig{

eth/ethconfig/config.go

@@ -128,8 +128,15 @@ type Config struct {
 	Genesis *core.Genesis `toml:",omitempty"`
 
 	// Protocol options
-	NetworkId              uint64 // Network ID to use for selecting peers to connect to
-	SyncMode               downloader.SyncMode
+	NetworkId uint64 // Network ID to use for selecting peers to connect to
+	SyncMode  downloader.SyncMode
+
+	// DisablePeerTxBroadcast is an optional config and disabled by default, and usually you do not need it.
+	// When this flag is enabled, you are requesting remote peers to stop broadcasting new transactions to you, and
+	// it does not mean that your node will stop broadcasting transactions to remote peers.
+	// If your node does care about new mempool transactions (e.g., running rpc services without the need of mempool
+	// transactions) or is continuously under high pressure (e.g., mempool is always full), then you can consider
+	// to turn it on.
 	DisablePeerTxBroadcast bool
 
 	// This can be set to list of enrtree:// URLs which will be queried for