Rblhost

This is a concept implementation of the blhost tool in Rust programming language. It includes McuBoot implementation, similar to the one in spsdk, together with spsdk-like Python bindings using pyo3 crate.

Features

• UART communication with configurable baudrate and timeout
• I2C communication with configurable slave address
• Command-line interface compatible with the original blhost tool
• Python bindings for integration with other tools
• C/C++ bindings

Performance Benchmark

The Rust implementation offers performance improvements compared to both the Python SPSDK implementation and the original C/C++ blhost tool.

Benchmark performed on MacBook Air M2 comparing rblhost with SPSDK blhost and C/C++ blhost 2.6.7. Benchmark measures get-property 1 command execution time with MCXN236 board and 57600 baud rate. Resulting time is in miliseconds.

Key performance highlights:

• Faster startup time compared to both Python and C++ implementations

• Improved command execution speed

• Native performance with the convenience of Python bindings

Installation

Prerequisites

• Rust toolchain
• For Python bindings: Python 3.8+ with development headers
• libudev-dev package (for Linux)

Building from Source

Clone the repository and cd into it:

git clone https://github.com/nxp-mcuxpresso/rblhost
cd rblhost

Refer to sections below to build bindings or the CLI tool.

Building CLI tool

Build the CLI tool:

cargo build --release

The binary will be available at target/release/rblhost. For example usage of the library, look in examples folder.

Building Python bindings

1. Create and activate a virtual environment.
2. Build rblhost with Python bindings

   cargo build --release --features python
   

3. Install pymboot into the virtual environment
   • Normal installation

     pip install .
     

   • Development installation:

     pip install -e .
     

For examples on how to use Python bindings, look into examples folder.

Building C bindings

Note: Compiling together python and c_api features/bindings may result in malfunctioning libraries.

Prerequisites:

• Rust toolchain (rustc, cargo)
• C compiler (gcc, clang)
• For Linux: libudev-dev package
• For macOS: Xcode command line tools

1. Run the following to build C bindings:

   cargo build --release --features c_api
   

2. This build process will:
   1. Compile the Rust library
   2. Generate C header files (compatible with C++) using cbindgen
   3. Create the shared library
3. Output files are:
   • Library:
     • Linux: target/release/libmboot.so
     • macOS: target/release/libmboot.dylib
     • Windows: target/release/mboot.dll
   • Header file: include/mboot.h

For more information about the bindings, refer to C Bindings section. For examples on how to use C bindings and an example CMakeLists.txt file, look into examples folder.

System-specific Requirements

Linux

• For UART: No additional requirements
• For I2C: The i2c-dev kernel module must be loaded

  sudo modprobe i2c-dev
  

Windows

• For UART: No additional requirements
• I2C communication is not supported on Windows

macOS

• For UART: No additional requirements

• I2C communication is not supported on macOS

CLI Usage

Basic Command Structure

rblhost [OPTIONS] -- COMMAND [ARGS]...

Communication Options

UART Connection

rblhost -p <port>[,<baudrate>] [OPTIONS] -- COMMAND [ARGS]...

• <port>: Serial port name (e.g., COM3, /dev/ttyUSB0)
• <baudrate>: Optional baudrate (default: 57600)

Example:

rblhost -p COM3,115200 -- reset

I2C Connection

Basic information:

1. Uses the Linux I2C device interface (/dev/i2c-X)
2. Supports specifying a slave address or uses the default (0x10)
3. Follows the same packet protocol as UART communication
4. Requires the i2c-dev kernel module to be loaded on Linux systems (refer to System-specific Requirements)

rblhost --i2c <device>:<slave_address> [OPTIONS] -- COMMAND [ARGS]...

• <device>: I2C device path in /dev/i2c-X format, where X is the I2C bus number
• <slave_address>: Optional slave address in hex format (e.g., 0x3A), default is 0x10

Example:

rblhost --i2c /dev/i2c-1:0x3A -- reset

Common Options

• -t, --timeout <MILLISECONDS>: Serial read timeout in milliseconds (default: 5000)
• -s, --silent: Suppress status response and response words
• -v, --verbose: Increase verbosity level (can be used multiple times)

Example with timeout:

rblhost -p COM3 -t 10000 -- flash-erase-all

Available Commands

• get-property: Queries various bootloader properties and settings
• reset: Reset the device
• execute: Jumps to code at the provided address
• call: Invokes code at an address, passing an argument to it
• flash-erase-all: Perform an erase of the entire flash memory
• fill-memory: Fills the memory with a pattern
• read-memory: Reads the memory and writes it to a file or stdout
• set-property: Changes properties and options in the bootloader
• configure-memory: Sets a config at internal memory to memory with ID
• flash-erase-all-unsecure: Erase Complete Flash and Unlock
• flash-erase-region: Erases one or more sectors of the flash memory
• write-memory: Write memory from a file or CLI
• fuse-program: Program fuse
• fuse-read: Reads the fuse and writes it to the file or stdout
• receive-sb-file: Receives a file in a Secure Binary (SB) format
• flash-read-once: Read from MCU flash program once region (eFuse/OTP)
• flash-program-once: Write into MCU program once region (eFuse/OTP)
• trust-provisioning: Group of subcommands related to trust provisioning
• key-provisioning: Group of subcommands related to key provisioning
• load-image: Sends a boot image file to the device

MBoot C Bindings

The MCU Boot library provides a C API that allows C/C++ applications to communicate with MCU bootloaders. The API provides functions for:

• Connecting to MCU bootloaders over UART
• Reading and writing memory
• Getting device properties
• Executing commands on the device

Including the Library

1. Include the header file in your C code:

   #include "mboot.h"
   

2. Compile your C program with the library:

   # Linux/macOS
   gcc -o my_program my_program.c -L./target/release -lmboot -Wl,-rpath,./target/release
   
   # Windows
   gcc -o my_program.exe my_program.c -L./target/release -lmboot
   

   You can also use cmake example in examples.

Look into the generated header to see all currently available functions.

Error Handling

The API functions return integer status codes:

• 0: Success
• -1: Invalid parameters (null pointers)
• -2: Invalid property tag
• -3: Communication error

All of these errors are specified as macros in the generated header. It's also possible to use mbot_get_status_text function to get a text description of the error during runtime.

Memory Management

All functions containing Allocations section in their documentation allocate data on heap, which must be later freed.

Thread Safety

The MCU Boot C API is not thread-safe. Do not use the same MBOOT_CMcuBoot instance from multiple threads simultaneously.

Troubleshooting

Library Not Found

If you get a "library not found" error when running your program:

• Linux: Set the LD_LIBRARY_PATH environment variable:

  export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:./target/release
  

• macOS: Set the DYLD_LIBRARY_PATH environment variable:

  export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:./target/release
  

• Windows: Add the library directory to your PATH or copy the DLL to the same directory as your executable.

Linking Errors

If you get undefined symbol errors when linking:

1. Make sure you're using the correct library name (-lmboot)

2. Check that the library path is correct (-L./target/release)

3. Verify that the library was built successfully

4. "Undefined reference to Py*" -- Build the library with only the c_api feature, like shown here:

   cargo build -rF c_api
   

License

This project is licensed under the BSD 3-Clause License - see the LICENSE file for details.

Missing and unimplemented features

• Implement all of blhost and McuBoot commands
• Add doc comments to everything This could be enforced by using lints in rustdoc.
• Implement missing python bindings
• Address all TODO and FIXME comments
• Add different texts for different board families
• Refactor and optimize the code

State of work

This table compares the commands available in rblhost (Rust implementation) with the original blhost (C implementation), and indicates which commands are supported in the Python bindings.