Refactor command execution into commands module

This patch refactors the command execution.  A command is represented by
a struct implementing the Command trait.  The enum_cmd macro is used to
generate a mapping from the CommandId enum to a Command instance and to
execute the command.  The request and response data is manually
converted from and to raw byte slices.

As we do not have a standard library, we cannot create a Box<Command>
from a CommandId.  Instead, we directly delegate the execute method to
the corresponding Command.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index e10f4d2..caf7fdf 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,6 +9,7 @@ extern crate panic_halt;
 #[macro_use]
 mod util;
 
+mod commands;
 mod device;
 mod hid;