김민수 Cortex-M4 Processor - Getting Started with the GNU Compiler Collection(gcc)

목차 1.Typical development flow 2.Creating a simple blinky project 3.Overview of the command line options 4.Flash programming 5.Using Keil MDK-ARM with GNU tools for ARM 6.Using CoIDE with GNU tools for ARM Embedded - Processors 7.Commercial gcc-based development suites

- The gcc toolchain contains a C compiler, assembler, linker, libraries, debugger and additional utilities. - Users can develop applications using C language, assembly language or a mixture of both. - The prefix of commands reflects the type of the prebuilt toolchain. 1. Typical development flow

- It is common for have the compile and link operations combined in one gcc run. 1. Typical development flow

- In order to make software development easier, the microcontroller vendors provide a set of files. 1. Typical development flow File typeDescriptions Application codeSource code of your application. Device-specific CMSIS Header filesThe definition header files. Device-specific startup code for gccThe device specific startup code. Device-specific system initialization filesSystemInit() function and additional functions for system clock updates. Generic CMSIS Header filesIn the device driver library package or tool installation. Linker scriptThe complete linker script can be composed of several files, with one file to specify the memory layout and other files to define the settings required for gcc itself. Library filesInclude the runtime libraries provided by the toolchain.

-The installation of GNU Tools for ARM Embedded Processors only provide command line tools. -Users can invoke the compilation using the command line, make file, batch file or using a third-party IDE. -In batch file case, the compilation and link process is carried out by arm-none-eabi-gcc. 2. Creating a simple blinky project

3. Overview of the command line options - Users can specify which target processor is to be used and which architecture is to be used. - By default the GNU C compiler uses a run-time library called Newlib(good performance but larger code size). - In version 4.7 of the GNU Tools for ARM Embedded Processors, Newlib-nano was introduced. It is optimized for size and can produce much smaller binary code.

4. Flash programming - The GNU Tools for ARM Embedded Processors do not include any flash programming support. So users need to use third-party tools to handle the flash programming Using Keil MDK-ARM - Users’ program image file extension of the executable needs to be changed to “.axf” Using third-party flash programming utilities - A common flash programming utility is CoFlash from coocox.org. - Users can select the program image that can be binary or executable image “.elf”.

5. Using Keil MDK-ARM with GNU tools for ARM - Users can select between using the ARM C compiler and using GNU C compiler. - Once the toolchain path is set up, users can add their program file to projects by using the Keil MDK normally. - Some of the project settings such as debug, trace and flash programming are the same as the normal MDK environment. However, other project settings are different and toolchain specific. - uVision automatically adds the location of the CMSIS-Core files in the Keil MDK-ARM installation to the include path.

6. Using CoIDE with GNU tools for ARM Embedded - Processors - The CoIDE does not include the GNU toolchain, so the GNU toolchain needs to be installed separately. 7. Commercial gcc-based development suites 7.1. Atollic TrueSTUDIO for ARM - The TrueSTUDIO is based on the gcc and Eclipse IDE. - Utilizing the Serial Wire Viewing(SWV) feature in the Cortex- M3&4 processors, TrueSTUDIO provides a wide range of analysis features.

7. Commercial gcc-based development suites 7.2. Red Suite - The Red Suite is a fully featured development suite for ARM based microcontrollers, which includes all the tools necessary to develop high-quality software solutions. - The Red Suite provides a comprehensive C/C++ programing environment and is based on Eclipse IDE. - Red Trace enables a high level of visualization of what is happening in the target device. - The debugger includes a peripheral viewer that provides complete visibility of all register and bit fields.

7. Commercial gcc-based development suites 7.3. CrossWorks for ARM - CrossWork for ARM is a C, C++ and assembly development suite. - It contains an IDE called CrossStudio which integrated the GNU toolchain. - The source-level debugger in Cross Studio can work with a number of debug adaptors.