The MR framework is a lightweight framework designed specifically for embedded systems. It fully considers the resource and performance requirements of embedded systems.

By providing standardized device management interfaces, it greatly simplifies the development of embedded applications and helps developers quickly build embedded applications.

The framework provides developers with standardized open, close, ioctl, read, write and other interfaces. It decouples the applications from the low-level hardware drivers. The applications do not need to know the implementation details of the drivers.

When the hardware changes, the applications can seamlessly migrate to the new hardware by only adapting the low-level drivers. This greatly improves the reusability of software and its extensibility to new hardware.

Key characteristic

Standardized device access interfaces
Decoupled application and driver development
Simplified lower-level driver and application development
Lightweight and easy to use with low resource usage
Modular design with loose coupling between components for independent development and extremely low hardware migration costs
Supported in bare-metal and operating system environments

Major component

Device framework: Provides standardized device access interfaces
Memory management: Dynamic memory management
Tools: Common data structures like lists, queues, balanced trees etc.
Various functional components

Standardized device interface

All operations of the device can be implemented through the following interfaces:

interface	describe
mr_dev_register	Registered device
mr_dev_open	Open device
mr_dev_close	Close device
mr_dev_ioctl	Control device
mr_dev_read	Read data from the device
mr_dev_write	Writes data to the device
mr_dev_isr	Device interrupt control

Configuration tool

MR provides Kconfig visual configuration tool that developers can configure without deep knowledge of the source code.

Kconfig will automatically generate the configuration options interface based on the configuration file. Developers can select the functional components that need to be enabled and set relevant parameters through simple operations.

By modifying parameters, you can quickly tailor the required functions. After the configuration is complete, the Python script automatically generates the configuration file.

Directory structure

name	describe
bsp	Board support package
components	Components
device	Device file
document	Document
driver	Driver file
include	Library header file
source	Library source file
Kconfig	Configuration files
kconfig.py	Automatic configuration script
LICENSE	Open-source license

Get Started

Configure the Kconfig Environment

Note: Kconfig is not mandatory, but recommended (installation and configuration are very quick, and the following tutorials are based on applying Kconfig).

Verify that the system has a Python environment installed. Run python --version in the command line to check the Python version (Kconfig depends on python, please install python if it is not available).

Use the following commands to install Kconfig in the command line:

python -m pip install windows-curses
python -m pip install kconfiglib

Run menuconfig -h in the command line to verify successful installation.

Import the Framework into the Project

Download the latest version source code from the Gitee or Github repository to the local.
Import the source code into the directory where your project is located. Taking an STM32 project as an example:
If the used chip has BSP adaptation, please refer to the chip's corresponding BSP configuration tutorial to complete the BSP configuration.
Remove unnecessary files such as bsp、document、module directories (you can also remove the .git file to delete GIT if not needed). The directory structure is shown below after completion:

Open the command line tool in the mr-library directory and run menuconfig to configure the menu.

Note: When the corresponding chip driver is added, Device configure and Driver configure will be displayed. Please refer to the tutorial under BSP for Driver configure.
Enter the menu by pressing the Enter key on Device configure, and configure the desired functions according to needs.
After configuration is complete, press Q to exit the menu configuration interface, press Y to save the configuration.

Generate Configuration File

Run python kconfig.py in the command line tool under mr-library directory to automatically generate the configuration file mr_config.h.

Add Include Paths

Add the include paths of mr-library in the compiler, taking keil as an example:
Configure automatic initialization (GCC environment), find the link script file with suffix .ld in your project directory (usually link.ld), and add the following code to the script file:
```
/* mr-library auto init */
. = ALIGN(4);
_mr_auto_init_start = .;
KEEP(*(SORT(.auto_init*)))
_mr_auto_init_end = .;
```
Example:
Include #include "include/mr_lib.h" in your project.
Add the automatic initialization function mr_auto_init(); in the main function.

Let's Light an LED

#include "include/mr_lib.h"

/* Define the LED pin-number (PC13) */
#define LED_PIN_NUMBER                  45

int main(void)
{
    /* Automatic initialization */
    mr_auto_init();

    /* Open the PIN device */
    int ds = mr_dev_open("pin", MR_OFLAG_RDWR);
    /* Set to the LED pin */
    mr_dev_ioctl(ds, MR_CTL_PIN_SET_NUMBER, mr_make_local(int, LED_PIN_NUMBER));
    /* Set the LED pin to push-pull output mode */
    mr_dev_ioctl(ds, MR_CTL_PIN_SET_MODE, mr_make_local(int, MR_PIN_MODE_OUTPUT));

    while(1)
    {
        /* Light up the LED */
        mr_dev_write(ds, mr_make_local(uint8_t, MR_PIN_HIGH_LEVEL), sizeof(uint8_t));
        mr_delay_ms(500);
        mr_dev_write(ds, mr_make_local(uint8_t, MR_PIN_LOW_LEVEL), sizeof(uint8_t));
        mr_delay_ms(500);
    }
}

Hello World

#include "include/mr_lib.h"

int main(void)
{
    /* Automatic initialization */
    mr_auto_init();

    /* Open the Serial-1 device */
    int ds = mr_dev_open("serial1", MR_OFLAG_RDWR);
    /* Output Hello World */
    mr_dev_write(ds, "Hello World\r\n", sizeof("Hello World\r\n"));
    
    while(1);
}

Now you have completed the basics, start exploring the MR library further.

Welcome to refer to more tutorials, document directory is in document.
You can try developing drivers based on certain chips to practice device driver programming.
Try writing more device templates and developing more features.
Welcome to provide your opinions and suggestions. If you are interested in development, you are welcome to participate in the development of the MR project. The project discussion group is: 199915649(QQ).

README_EN.md

MR frame

Brief introduction