ThreadX RTOS快速入门

ThreadX 是由 Express Logic 开发的一款硬实时操作系统，是唯一同时通过汽车电子、工业控制和医疗设备等高安全认证的RTOS，起初是收费RTOS，在2019年微软收购后，改为MIT开源协议，商用免费，是目前最强开源RTOS，具有完整的全家桶，如GUIX、NetX、NetX Duo、FileX、USBX。
2019年微软收购Express Logic, 2023年，微软把ThreadX捐给Eclipse基金会，ThreadX经过3次改名:

• ThreadX (2019年之前)
• Azure RTOS (2019~2023年)
• Eclipse ThreadX (2023年之后)

在叫Azure RTOS时，有大量示例代码，开箱即用，改为Eclipse ThreadX后，采用简洁模式，没什么示例代码了，想用就要自己移植，相比由Linux基金会托管的Zephyr RTOS就有比较完整的支持平台和示例代码，微软选择Eclipse基金会而不选择Linux基金会运营ThreadX，真的感到惋惜。

我们使用树莓派 pico rp2040进行测试，由于threadx没有适配这款设备，我们进行简单的移植，开发平台是ubuntu 22.04, gcc交叉编译器。

1. 安装开发环境

$ sudo apt install build-essential flex bc gawk texinfo file liblz4-dev ssh git libssl-dev libncurses-dev cmake
$ sudo apt install gcc-arm-none-eabi libnewlib-arm-none-eabi libstdc++-arm-none-eabi-newlib pkg-config libusb-1.0-0-dev

2. 设置Pico开发环境

下载树莓派官方pico相关代码:

$ mkdir -p ~/pico
$ cd ~/pico
$ git clone --recurse-submodules https://github.com/raspberrypi/pico-sdk.git
$ git clone https://github.com/raspberrypi/picotool.git
$ git clone https://github.com/raspberrypi/pico-examples.git

设置环境变量:

$ export PICO_SDK_PATH=$HOME/pico/pico-sdk

编译安装picotool:

$ cd ~/pico/picotool/
$ mkdir build
$ cd build/
$ cmake ..
$ make -j4
$ sudo make install

3. 移植ThreadX

创建文件夹和下载ThreadX源码:

$ mkdir -p ~/pico/pico-threadx
$ cd ~/pico/pico-threadx
$ mkdir -p samples/blink
$ git clone https://github.com/eclipse-threadx/threadx.git

目录如下:

$ ls ~/pico/
pico-examples  pico-sdk  pico-threadx  picotool

代码git id:

$ cd ~/pico/pico-threadx/threadx
$ git branch -vv
* master 7ad78c40 [origin/master] Merge pull request #387 from netomi/patch-1

设置pico-threadx相关文件：

$ cp ~/pico/pico-examples/CMakeLists.txt ~/pico/pico-threadx
$ cp ~/pico/pico-examples/pico_sdk_import.cmake ~/pico/pico-threadx
$ cp ~/pico/pico-examples/i2c/CMakeLists.txt ~/pico/pico-threadx/samples
$ cp ~/pico/pico-examples/blink/CMakeLists.txt ~/pico/pico-threadx/samples/blink
$ cp ~/pico/pico-threadx/threadx/ports_module/cortex_m0+/gnu/example_build/sample_threadx/tx_initialize_low_level.S ~/pico/pico-threadx/samples/blink
$ cp ~/pico/pico-threadx/threadx/ports_module/cortex_m0+/gnu/example_build/sample_threadx/sample_threadx.c ~/pico/pico-threadx/samples/blink

最终目录如下:

$ cd ~/pico/pico-threadx
$ tree -L 3 .
.
├── CMakeLists.txt
├── pico_sdk_import.cmake
├── samples
│   ├── blink
│   │   ├── CMakeLists.txt
│   │   ├── sample_threadx.c
│   │   └── tx_initialize_low_level.S
│   └── CMakeLists.txt
└── threadx
    └── ...

上面3个CMakeLists.txt都需要进行一些修改。

由于官方不同版本的代码可能有所不同，这里不使用diff，直接贴出修改后的最终文件:

1. ~/pico/pico-threadx/CMakeLists.txt

cmake_minimum_required(VERSION 3.12)

# Pull in SDK (must be before project)
include(pico_sdk_import.cmake)

project(pico_examples C CXX ASM)

set(CMAKE_C_STANDARD 11)
set(CMAKE_CXX_STANDARD 17)

set(PICO_EXAMPLES_PATH ${PROJECT_SOURCE_DIR})

# Initialize the SDK
pico_sdk_init()

function(add_subdirectory_exclude_platforms NAME)
    if (ARGN)
        if (PICO_PLATFORM IN_LIST ARGN)
            message("Skipping ${NAME} example which is unsupported on this platform")
            return()
        endif()
        foreach(PATTERN IN LISTS ARGN)
            string(REGEX MATCH "${PATTERN}" MATCHED "${PICO_PLATFORM}")
            if (MATCHED)
                message("Skipping ${NAME} example which is unsupported on this platform")
                return()
            endif()
        endforeach()
    endif()
    add_subdirectory(${NAME})
endfunction()

set(THREADX_ARCH "cortex_m0")
set(THREADX_TOOLCHAIN "gnu")

add_subdirectory(threadx)
add_subdirectory(samples)

2. ~/pico/pico-threadx/samples/CMakeLists.txt

add_subdirectory_exclude_platforms(blink)

3. ~/pico/pico-threadx/samples/blink/CMakeLists.txt

project(blink)

add_executable(${PROJECT_NAME}
    tx_initialize_low_level.S
    sample_threadx.c
    )

# pull in common dependencies
target_link_libraries(${PROJECT_NAME} pico_stdlib cmsis_core threadx)

pico_enable_stdio_usb(${PROJECT_NAME} 1)

# create map/bin/hex file etc.
pico_add_extra_outputs(${PROJECT_NAME})

4. ~/pico/pico-threadx/samples/blink/tx_initialize_low_level.S

@
    .global  _tx_thread_system_stack_ptr
    .global  _tx_initialize_unused_memory
@   .global  __RAM_segment_used_end__
    .global  _tx_thread_context_save
    .global  _tx_thread_context_restore
    .global  _tx_timer_interrupt
    .global  ram_vector_table
@
@
SYSTEM_CLOCK      =   125000000
SYSTICK_CYCLES    =   ((SYSTEM_CLOCK / 100) -1)

    .text
    .align 4
    .syntax unified

@VOID   _tx_initialize_low_level(VOID)
@{
    .global  _tx_initialize_low_level
    .thumb_func
_tx_initialize_low_level:
@
@    /* Disable interrupts during ThreadX initialization.  */
@
    CPSID   i
@
@    /* Set base of available memory to end of non-initialised RAM area.  */
@     
@   LDR     r0, =_tx_initialize_unused_memory       @ Build address of unused memory pointer
@   LDR     r1, =__RAM_segment_used_end__           @ Build first free address   
@   ADDS    r1, r1, #4                              @ 
@   STR     r1, [r0]                                @ Setup first unused memory pointer
@
@    /* Enable the cycle count register.  */
@    /* Not all M0 have DWT, uncomment if you have a DWT and want to use it. */
@    LDR     r0, =0xE0001000                         @ Build address of DWT register
@    LDR     r1, [r0]                                @ Pickup the current value
@    MOVS    r2, #1
@    ORRS    r1, r1, r2                              @ Set the CYCCNTENA bit
@    STR     r1, [r0]                                @ Enable the cycle count register 
@
@    /* Setup Vector Table Offset Register.  */
@    
    LDR     r0, =0xE000E000                         @ Build address of NVIC registers
    LDR     r2, =0xD08                              @ Offset to vector base register
    ADD     r0, r0, r2                              @ Build vector base register
    LDR     r1, =ram_vector_table                   @ Pickup address of vector table
    STR     r1, [r0]                                @ Set vector table address    
@
@    /* Set system stack pointer from vector value.  */
@
    LDR     r0, =_tx_thread_system_stack_ptr        @ Build address of system stack pointer
    LDR     r1, =ram_vector_table                   @ Pickup address of vector table
    LDR     r1, [r1]                                @ Pickup reset stack pointer
    STR     r1, [r0]                                @ Save system stack pointer
@
@    /* Configure SysTick for 100Hz clock, or 16384 cycles if no reference.  */
@
    LDR     r0, =0xE000E000                         @ Build address of NVIC registers
    LDR     r1, =SYSTICK_CYCLES
    STR     r1, [r0, #0x14]                         @ Setup SysTick Reload Value
    LDR     r1, =0x7                                @ Build SysTick Control Enable Value
    STR     r1, [r0, #0x10]                         @ Setup SysTick Control
@
@    /* Configure handler priorities.  */
@
    LDR     r1, =0x00000000                         @ Rsrv, UsgF, BusF, MemM
    LDR     r0, =0xE000E000                         @ Build address of NVIC registers
    LDR     r2, =0xD18                              @
    ADD     r0, r0, r2                              @ 
    STR     r1, [r0]                                @ Setup System Handlers 4-7 Priority Registers
    LDR     r1, =0xFF000000                         @ SVCl, Rsrv, Rsrv, Rsrv
    LDR     r0, =0xE000E000                         @ Build address of NVIC registers
    LDR     r2, =0xD1C                              @ 
    ADD     r0, r0, r2                              @ 
    STR     r1, [r0]                                @ Setup System Handlers 8-11 Priority Registers
                                                    @ Note: SVC must be lowest priority, which is 0xFF
    LDR     r1, =0x40FF0000                         @ SysT, PnSV, Rsrv, DbgM
    LDR     r0, =0xE000E000                         @ Build address of NVIC registers
    LDR     r2, =0xD20                              @   
    ADD     r0, r0, r2                              @ 
    STR     r1, [r0]                                @ Setup System Handlers 12-15 Priority Registers
                                                    @ Note: PnSV must be lowest priority, which is 0xFF
        
@
@    /* Return to caller.  */
@    
    BX      lr 
@}
@
@ /* System Tick timer interrupt handler */
    .global  __tx_SysTickHandler
    .global  SysTick_Handler
    .thumb_func
__tx_SysTickHandler:
    .thumb_func
SysTick_Handler:
@ VOID SysTick_Handler (VOID)
@ {
@
    PUSH    {r0, lr}
#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY
    BL      _tx_execution_isr_enter                 @ Call the ISR enter function
#endif
    BL      _tx_timer_interrupt
#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY
    BL      _tx_execution_isr_exit                  @ Call the ISR exit function
#endif
    POP     {r0, r1}
    MOV     lr, r1
    BX      lr
@ }

5. ~/pico/pico-threadx/samples/blink/sample_threadx.c (文件太大， 给出diff)

--- threadx/ports_module/cortex_m0+/gnu/example_build/sample_threadx/sample_threadx.c
+++ samples/blink/sample_threadx.c
@@ -2,7 +2,11 @@
    threads of different priorities, using a message queue, semaphore, mutex, event flags group,
    byte pool, and block pool.  */

+#include <stdio.h>
 #include "tx_api.h"
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+

 #define DEMO_STACK_SIZE         1024
 #define DEMO_BYTE_POOL_SIZE     9120
@@ -57,7 +61,7 @@ void    thread_6_and_7_entry(ULONG threa

 int main()
 {
-
+    stdio_init_all();
     /* Enter the ThreadX kernel.  */
     tx_kernel_enter();
 }
@@ -179,7 +183,9 @@ void    thread_0_entry(ULONG thread_inpu
 {

 UINT    status;
-
+    gpio_init(PICO_DEFAULT_LED_PIN);
+    gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+    gpio_put(PICO_DEFAULT_LED_PIN, 0);

     /* This thread simply sits in while-forever-sleep loop.  */
     while(1)
@@ -188,8 +194,15 @@ UINT    status;
         /* Increment the thread counter.  */
         thread_0_counter++;

+       if (thread_0_counter % 2 == 0) {
+            gpio_put(PICO_DEFAULT_LED_PIN, 1);
+        } else {
+            gpio_put(PICO_DEFAULT_LED_PIN, 0);
+        }
+
+       printf("hello world: %d.\n", thread_0_counter++);
         /* Sleep for 10 ticks.  */
-        tx_thread_sleep(10);
+        tx_thread_sleep(100);

         /* Set event flag 0 to wakeup thread 5.  */
         status =  tx_event_flags_set(&event_flags_0, 0x1, TX_OR);

直接复制替换掉原有内容，或修改diff代码即可。

后续，如果想要添加新的示例代码，则可以在blink同一级:

• ’pico-threadx/samples/CMakeLists.txt‘
• 'pico-threadx/samples/blink/*'

添加相应的文件和配置即可，另外，比如netx等移植时，则跟threadx处于相同一级目录即可。

4. 编译验证

编译:

$ cd ~/pico/pico-threadx
$ mkdir build
$ cd build
$ cmake ..
$ make -j4

 其中blink文件夹下会生成blink.uf2:

$ ls ~/pico/pico-threadx/build/samples/blink
...
blink.uf2
...

直接把blink.uf2复制到raspberry pi pico的内存中，就会看到板载LED闪烁和串口打印数据了。