Download and install custom target JSONs automatically

Cargo.toml

@@ -11,7 +11,7 @@ edition = "2018"
 
 [dependencies]
 cargo_metadata = "0.11.0"
-clap = { version = "3.1.12", features = ["derive"] }
+clap = { version = "4.1.8", features = ["derive"] }
 goblin = "0.2.3"
 serde = "1.0"
 serde_derive = "1.0"

README.md

@@ -2,11 +2,14 @@
 
 Builds a Nano App and outputs a JSON manifest file that can be used by [ledgerctl](https://github.com/LedgerHQ/ledgerctl) to install an application directly.
 
-In order to build for Nano S, Nano X, and Nano S Plus, [custom target files](https://docs.rust-embedded.org/embedonomicon/custom-target.html) are used. They can be found at the root of the [Rust SDK](https://github.com/LedgerHQ/ledger-nanos-sdk/).
+In order to build for Nano S, Nano X, and Nano S Plus, [custom target files](https://docs.rust-embedded.org/embedonomicon/custom-target.html) are used. They can be found at the root of the [Rust SDK](https://github.com/LedgerHQ/ledger-nanos-sdk/) and can be installed automatically with the command `setup`.
 
 ## Installation
 
-Only `arm-none-eabi-objcopy` is needed.
+This program requires:
+
+- `arm-none-eabi-objcopy`
+- [`ledgerctl`](https://github.com/LedgerHQ/ledgerctl)
 
 Install this repo with:
 
@@ -23,28 +26,32 @@ cargo install --path .
 Note that `cargo`'s dependency resolver may behave differently when installing, and you may end up with errors.
 In order to fix those and force usage of the versions specified in the tagged `Cargo.lock`, append `--locked` to the above commands.
 
-### Setting up custom targets
-
-The preferred method is to have all custom target files (`nanos.json`, `nanox.json` and `nanosplus.json`) in a separate folder, and set an environment variable called `LEDGER_TARGETS` pointing to this folder.
+## Usage
 
-`cargo ledger` will check for this environment variable (or default to "" if it is empty) to fetch the current target specification.
+General usage is displayed when invoking `cargo ledger`.
 
-## Usage
+### Setup
 
+This will install custom target files from the SDK directly into your environment.
 
 ```
-cargo ledger nanos
-cargo ledger nanox
-cargo ledger nanosplus
+cargo ledger setup
 ```
 
-Loading can optionally be performed by appending `--load` or `-l` to the command.
+### Building
+
+```
+cargo ledger build nanos
+cargo ledger build nanox
+cargo ledger build nanosplus
+```
 
-By default, this program will attempt to build the current program with in `release` mode (full command: `cargo build -Zbuild-std -Zbuild-std-features=compiler-builtins-mem --release --target=nanos.json --message-format=json`)
+Loading on device can optionally be performed by appending `--load` or `-l` to the command.
 
+By default, this program will attempt to build the current program with in `release` mode (full command: `cargo build --release --target=nanos --message-format=json`)
 
 Arguments can be passed to modify this behaviour after inserting a `--` like so:
 
 ```
-cargo ledger nanos --load -- --features one -Z unstable-options --out-dir ./output/
+cargo ledger build nanos --load -- --features one -Z unstable-options --out-dir ./output/
 ```