docs(x/evmutil): Remove akava and evmbankkeeper from spec (#1968)

x/evmutil/spec/01_concepts.md

@@ -4,34 +4,6 @@ order: 1
 
 # Concepts
 
-## EVM Gas Denom
-
-In order to use the EVM and be compatible with existing clients, the gas denom used by the EVM must be in 18 decimals. Since `ukava` has 6 decimals of precision, it cannot be used as the EVM gas denom directly.
-
-To use the Kava token on the EVM, the evmutil module provides an `EvmBankKeeper` that is responsible for the conversion of `ukava` and `akava`. A user's excess `akava` balance is stored in the `x/evmutil` store, while its `ukava` balance remains in the cosmos-sdk `x/bank` module.
-
-## `EvmBankKeeper` Overview
-
-The `EvmBankKeeper` provides access to an account's total `akava` balance and the ability to transfer, mint, and burn `akava`. If anything other than the `akava` denom is requested, the `EvmBankKeeper` will panic.
-
-This keeper implements the `x/evm` module's `BankKeeper` interface to enable the usage of `akava` denom on the EVM.
-
-### `x/evm` Parameter Requirements
-
-Since the EVM denom `akava` is required to use the `EvmBankKeeper`, it is necessary to set the `EVMDenom` param of the `x/evm` module to `akava`.
-
-### Balance Calculation of `akava`
-
-The `akava` balance of an account is derived from an account's **spendable** `ukava` balance times 10^12 (to derive its `akava` equivalent), plus the account's excess `akava` balance that can be accessed via the module `Keeper`.
-
-### `akava` <> `ukava` Conversion
-
-When an account does not have sufficient `akava` to cover a transfer or burn, the `EvmBankKeeper` will try to swap 1 `ukava` to its equivalent `akava` amount. It does this by transferring 1 `ukava` from the sender to the `x/evmutil` module account, then adding the equivalent `akava` amount to the sender's balance in the module state.
-
-In reverse, if an account has enough `akava` balance for one or more `ukava`, the excess `akava` balance will be converted to `ukava`. This is done by removing the excess `akava` balance in the module store, then transferring the equivalent `ukava` coins from the `x/evmutil` module account to the target account.
-
-The swap logic ensures that all `akava` is backed by the equivalent `ukava` balance stored in the module account.
-
 ## ERC20 token <> sdk.Coin Conversion
 
 `x/evmutil` facilitates moving assets between Kava's EVM and Cosmos co-chains. This must be handled differently depending on which co-chain to which the asset it native. The messages controlling these flows involve two accounts:
@@ -65,7 +37,3 @@ EVM-native asset conversion is done through the use of the `MsgConvertERC20ToCoi
 Only ERC20 contract address that are in the `EnabledConversionPairs` param (see **[Params](05_params.md)**) can be converted via these messages.
 
 `EnabledConversionPairs` can be altered through governance.
-
-## Module Keeper
-
-The module Keeper provides access to an account's excess `akava` balance and the ability to update the balance.

x/evmutil/spec/02_state.md

@@ -51,24 +51,12 @@ message AllowedCosmosCoinERC20Token {
 
 ```protobuf
 message GenesisState {
-  repeated Account accounts = 1 [(gogoproto.nullable) = false];
+  // previously stored accounts containing fractional balances.
+  reserved 1;
   Params params = 2 [(gogoproto.nullable) = false];
 }
 ```
 
-## Account
-
-An `Account` is a struct representing the excess `akava` balance of an address.
-
-Since an address's total `akava` balance is derived from its `ukava` balance and the excess `akava` balance stored by the `Account` struct, the `akava` balance here should never exceed 1 `ukava` (10^12 `akava`).
-
-```protobuf
-message Account {
-  bytes address = 1;
-  string balance = 2;
-}
-```
-
 ## Deployed Cosmos Coin Contract Addresses
 
 Addresses for the ERC20 contracts representing cosmos-sdk `Coin`s are kept in the module store. They are stored as bytes by the cosmos-sdk denom they represent.

x/evmutil/spec/README.md

@@ -21,13 +21,6 @@ parent:
 
 The evmutil module provides additional functionalities on top of the evm module.
 
-### EVM `akava` Usage
-
-evmutil stores additional state data for evm accounts and exposes an `EvmBankKeeper` that should be used by the `x/evm` keeper for bank operations.
-The purpose of the `EvmBankKeeper` is to allow the usage of the `akava` balance on the EVM via an account's existing `ukava` balance. This is needed because the EVM gas token use 18 decimals, and since `ukava` has 6 decimals, it cannot be used as the EVM gas denom directly.
-
-For additional details on how balance conversions work, see **[Concepts](01_concepts.md)**.
-
 ### ERC20 Token <> sdk.Coin Conversion
 
 evmutil exposes messages to allow for the conversion of Kava ERC20 tokens and sdk.Coins via a whitelist.