Reworking the Cmdline crate

Redesigning the Cmdline crate to be able to handle boot args and
init args properly. The Cmdline struct now contains two strings
which will store the boot args and init args separately. When
the kernel command line is needed, we join those to strings,
adding a ' -- ' delimiter between them.

Signed-off-by: Traistaru Andrei Cristian <[email protected]>

Author: Traistaru Andrei Cristian

CHANGELOG.md

@@ -1,3 +1,20 @@
+# [Unreleased]
+
+## Added
+- Added `NoBootArgsInserted` error type used when calling `as_cstring` on a `Cmdline`
+  containing only init args.
+- Added `InvalidCapacity` error type used when trying to create a `Cmdline`
+  either with zero capacity (using `new` or `try_from`) or with smaller capacity
+  than required for arguments (using `try_from`).
+- Added `insert_init_args` method allowing insertion of init arguments into `Cmdline`.
+
+## Changed
+- Removed `InvalidDevice` error type (it wasn't used anywhere).
+- Replaced `From` with `TryFrom<Cmdline>` for `Vec<u8>` to be able
+  to propagate errors returned by `as_cstring` when converting a `Cmdline` to `Vec<u8>`.
+- Support added for both boot and init arguments in `try_from`.
+- Changed `new` to return `Result` for invalid command line capacity handling.
+
 # [v0.6.0]
 
 ## Changed

coverage_config_x86_64.json

@@ -1,5 +1,5 @@
 {
-  "coverage_score": 76.2,
+  "coverage_score": 77.6,
   "exclude_path": "",
   "crate_features": "bzimage,elf",
   "exclude_path": "benches/,loader_gen/"