docs: first update (#188)

* docs: update

* update +

* txs

* update docs

* more docs

* spec update

* doc fixes

docs/core/README.md

@@ -10,5 +10,6 @@ This repository contains reference documentation on the core concepts of Ethermi
 
 1. [Encoding](./encoding.md)
 2. [Pending State](./pending_state.md)
+3. [Protobuf Docs](./proto-docs.md)
 
 After reading the core concepts, head on to the [guides](../guides/README.md) to learn how to use Ethereum tooling with Ethermint.

docs/core/encoding.md

@@ -17,14 +17,14 @@ Learn about the encoding formats used on Ethermint. {synopsis}
 
 The Cosmos [Stargate](https://stargate.cosmos.network/) release introduces
 [protobuf](https://developers.google.com/protocol-buffers) as the main encoding format for both
-client and state serialization. All the EVM module structs that are used for state and clients
+client and state serialization. All the EVM module types that are used for state and clients
 (transaction messages, genesis, query services, etc) will be implemented as protocol buffer messages.
 
 ### Amino
 
 The Cosmos SDK also supports the legacy Amino encoding format for backwards compatibility with
-previous versions, specially for client encoding. Ethermint will not support Amino in the EVM module
-once the migration to SDK `v0.40` is finalized.
+previous versions, specially for client encoding and signing with Ledger devices. Ethermint does not
+support Amino in the EVM module, but it is supported for all other Cosmos SDK modules that enable it.
 
 ### RLP
 
@@ -33,9 +33,36 @@ allows for quick reconstruction of encoded data. Ethermint uses RLP to encode/de
 messages for JSON-RPC handling to conform messages to the proper Ethereum format. This allows
 messages to be encoded and decoded in the exact format as Ethereum's.
 
-Each message type defined on the EVM module define the `EncodeRLP` and `DecodeRLP` methods which
-implement the `rlp.Encoder` and `rlp.Decoder` interfaces respectively. The RLP encode method is used
-to sign bytes and transactions in `RLPSignBytes` and `Sign`.
+The `x/evm` transactions (`MsgEthereumTx`) encoding is performed by casting the message to a go-ethereum's `Transaction` and then marshaling the transaction data using RLP:
+
+```go
+// TxEncoder overwrites sdk.TxEncoder to support MsgEthereumTx
+func (g txConfig) TxEncoder() sdk.TxEncoder {
+  return func(tx sdk.Tx) ([]byte, error) {
+    msg, ok := tx.(*evmtypes.MsgEthereumTx)
+    if ok {
+      return msg.AsTransaction().MarshalBinary()
+   }
+    return g.TxConfig.TxEncoder()(tx)
+  }
+}
+
+// TxDecoder overwrites sdk.TxDecoder to support MsgEthereumTx
+func (g txConfig) TxDecoder() sdk.TxDecoder {
+  return func(txBytes []byte) (sdk.Tx, error) {
+    tx := &ethtypes.Transaction{}
+
+    err := tx.UnmarshalBinary(txBytes)
+    if err == nil {
+      msg := &evmtypes.MsgEthereumTx{}
+      msg.FromEthereumTx(tx)
+      return msg, nil
+    }
+
+    return g.TxConfig.TxDecoder()(txBytes)
+  }
+}
+```
 
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