freeRTOS中文学习

The port was developed by John Feller on an ATEB40X prototyping board from Embest (Atmel AT91EB40 clone) using the open

source GCC development tools (想用这里的指令就用上面两块板之一).

The development board came with a parallel port JTAG interface and flash programming utility. 并口 JTAG 接口和 FLASH 编程功能

As downloaded this demo application does not demonstrate the use of co-routines. See the co-routine documentation page for

information on how co-routine functionality can be quickly added to this demonstration. 联合程序

IMPORTANT! Notes on using the AT91R40008 RTOS port

Please read all the following points before using this RTOS port.

1. Source Code Organisation

The AT91R40008 GCC demo application makefile 包含

在 FreeRTOS/Demo/ARM7_AT91FR40008_GCC 目录中.

The directory FreeRTOS/Demo/ARM7_AT91FR40008_GCC/Serial contains a sample

interrupt driven serial port driver. 包含示例中断驱动串口驱动程序

The Demo Application

The FreeRTOS source code download includes a fully preemptive multitasking demo application for the AT91 GCC RTOS port. 完全

抢占多任务演示

ARM, THUMB, ROM and RAM builds

The following batch files are provided to build the demo application. The batch files set the environment variables necessary for the

relevant built before calling make.

 ROM_ARM.bat - Creates an ARM mode release build suitable for programming into flash.

The demo application includes the ComTest tasks - where one task transmits RS232 characters to another. For correct operation of

this real time task a loopback connector must be fitted to the RS232 port 0 of the Embest prototyping board (pins 2 and 3 must be

connected together on the 9Way connector).

The demo application uses the LEDs built onto the prototyping board so no further hardware setup is required.

Building and executing the RTOS demo application - Standalone

from flash

tools are already installed correctly and included in your PATH (to make them available from a Windows DOS prompt).

To build the application:

1. Open a DOS prompt, and navigate to the Demo/ARM7_AT91FR40008_GCC directory.

2. Type "rom_arm" (or "rom_thumb") to execute the rom_arm.bat batch file. The batch file sets up the environment

necessary for a release build then calls make. The build should complete with no errors or warnings.

Demo/ARM7_AT91FR40008/rtosdemo.hex. This is the hex file output from the build

process described above.

5. Erase the flash contents by pressing the Erase button, then reprogram the flash by pressing the Program button.

Executing the demo application:

Power down the prototyping board, remove the JTAG interface, then apply power again. The demo application will start to execute.

Building and executing the RTOS demo application - Debug

from RAM

The port authour has also tested and provided linker scripts for RAM execution.

See the corresponding section on the LPC2106 ARM7 GCC port documentation page for details of using the GCC debug tools.

 When the loopback connector is in place every character transmitted by the ComTest Tx task is received by the ComTest

Rx task. Each transmitted character causes LED D8 to toggle, each correctly received character causes LED D7 to toggle.

LED D7 will only toggle if the received character matches the character the ComTest Rx task expected to receive.

 Not all the tasks update an LED so have no visible indication that they are operating correctly. Therefore a 'Check' task is

created whose job it is to ensure that no errors have been detected in any of the other tasks.

LED D10 is under control of the 'Check' task. Every three seconds the 'Check' task examines all the tasks in the system to

ensure they are executing without error. It then toggles LED D10. If LED D10 is toggling every three seconds then no