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| permalink: /trustzone-sdk-docs/ta-development-modes.md |
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| |
| # TA Development Modes |
| |
| ## Comparison |
| |
| ### `no-std` |
| |
| - **Pros**: |
| - Reuses standard Rust tier-1 toolchain targets (`aarch64-unknown-linux-gnu`, |
| `arm-unknown-linux-gnueabihf`). |
| - Significant performance improvements. |
| - Substantial reduction in binary size. |
| |
| - **Cons**: |
| - Limited support for third-party crates. In the no-std mode, Trusted |
| Applications (TAs) are unable to utilize crates dependent on the standard |
| library (std). |
| |
| ### `std` |
| |
| - **Pros**: |
| - Enables the utilization of more third-party crates, including those |
| requiring `std`, such as `rustls`, which are essential for functionality. |
| |
| - **Cons**: |
| - Manual porting of `std` with infrequent updates. Currently using `std` |
| version `1.80.0` and `Rust` version `nightly-2024-05-14`, which might not |
| meet the MSRV requirements of some crates. |
| |
| ## Supported Examples |
| |
| - **Common**: See |
| [Overview of OP-TEE Rust Examples](https://teaclave.apache.org/trustzone-sdk-docs/overview-of-optee-rust-examples/). |
| |
| - **`no-std`**: Excludes `test_serde`, `test_message_passing_interface`, |
| `test_tls_client`, `test_tls_server`, `test_secure_db_abstraction`. |
| |
| - **`std`**: Excludes `test_mnist_rs`, `test_build_with_optee_utee_sys`. |
