Table of contents
3. Installation of the cross-compilation chain
1. What is cross compilation
Cross-compilation refers to the compilation of programs written in one programming language into programs in another programming language, usually for use in different operating systems or hardware environments. This compilation process produces one or more binary files that can be run on another operating system or hardware environment. In short, it is to generate executable code for another platform on one platform.
2. Why cross compile?
1. Due to the lack of resources on the target platform, the compiler we need cannot be run
2. Does the Raspberry Pi not require cross-compilation?
wrong. Also, Raspberry Pi is sometimes because the target platform has not yet been established, and there is no operating system, so it is impossible to talk about running any compiler. The operating system is also code and must be compiled!
The platform needs at least two things: bootloader (boot code) and operating system core
Host (host): The platform for editing and compiling programs, generally an X86-based PC, also known as a host.
Target machine (target): The system developed by the user is usually a non-X86 platform. The executable code compiled by the host runs on the target.
3. Installation of the cross-compilation chain
1. Open the URL: https://github.com/raspberrypi/
2. Select tool
3. Click to download
4. Create a new folder and copy it from the shared folder to the working directory
cp /mnt/hgfs/share/tools-master.zip .Put the downloaded tools-master.zip into it and unzip it
unzip tools-master.zip5. Go to the corresponding file
cd tools-master
cd arm-bcm2708/
cd gcc-linaro-arm-linux-gnueabihf-raspbian-x64
cd /bin
6. Configure environment variables
echo $PATH shows environment variables
Configure temporary environment variables
export PATH=/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/CLC/lessonPI/tools-master/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/binOr you can also configure permanent and effective environment variables
Modify the .bashrc hidden file in the working directory
vi /home/liujiaxin/.bashrc Add in the last line of the file:
export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/liujiaxin/lessonPi/tools-master/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin
Load the configuration file and the configuration will take effect immediately.
4. Related usage methods
1. How to use cross-compilation:
arm-linux-gnueabihf-gcc xxx.c -o xxx
2. Use the -v parameter to view the version information of the GCC compiler
3. Upload the virtual machine code to the Raspberry Pi
scp clientInPi [email protected]:/home/Command File Name Development Board Username@Development Board Address: Absolute path of the development board
4.file Executable file name: View file type
Five. Soft connection
Soft link concept: 1. Soft link files have shortcuts similar to Windows.
2. In a symbolic link, the file is actually a text file that contains information about the location of another file.
3. Generate a mirror image of the file on the location you choose, which will not take up disk space
How to generate:
ln -s libwiringPi.so.2.50 libwiringPi.so