How to Cross-Compile C Programs for Raspberry Pi Using GCC on Ubuntu

Introduction

Cross-compiling a C program for the Raspberry Pi using GCC on Ubuntu is a powerful skill that allows developers to build applications for the Raspberry Pi from a more robust environment. This tutorial will guide you through the process of setting up your environment, creating a simple C program, and using a Makefile to streamline the build process.

Prerequisites

• Ubuntu operating system (18.04 or later recommended)
• Basic knowledge of C programming
• Familiarity with the command line
• Access to a Raspberry Pi (for testing the compiled program)

Parts/Tools

• GCC (GNU Compiler Collection)
• Raspberry Pi cross-compiler toolchain
• Make utility
• Text editor (e.g., Vim, Nano, Visual Studio Code)

Steps

1. Install Required Packages
   1. Open a terminal and update your package list:

   sudo apt update

   2. Install the cross-compiler toolchain:

   sudo apt install gcc-arm-linux-gnueabi

   3. Install Make utility:

   sudo apt install make

2. Create Your C Program
   1. Create a new directory for your project:

   mkdir my_raspberry_pi_project && cd my_raspberry_pi_project

   2. Create a C file, e.g., hello.c:

   nano hello.c

   3. Write a simple C program:

   
   #include <stdio.h>
   
   int main() {
       printf("Hello, Raspberry Pi!n");
       return 0;
   }
               

   4. Save and exit the editor.
3. Create a Makefile
   1. Create a file named Makefile:

   nano Makefile

   2. Write the following content in the Makefile:

   
   CC = arm-linux-gnueabi-gcc
   CFLAGS = -Wall -Wextra
   TARGET = hello
   
   all: $(TARGET)
   
   $(TARGET): hello.o
       $(CC) $(CFLAGS) -o $@ $^
   
   hello.o: hello.c
       $(CC) $(CFLAGS) -c $<
   
   clean:
       rm -f $(TARGET) *.o
               

   3. Save and exit the editor.
4. Compile Your Program
   1. Run the following command in the terminal:

   make

   2. If successful, you should see hello executable in your directory.
5. Transfer and Test on Raspberry Pi
   1. Transfer the compiled program to your Raspberry Pi using SCP:

   scp hello pi@:~

   2. SSH into your Raspberry Pi:

   ssh pi@

   3. Run the program:

   ./hello

   4. You should see the output: Hello, Raspberry Pi!

Troubleshooting

• Issue: Compiler not found.

Solution: Ensure you have installed the cross-compiler toolchain correctly. Check with which arm-linux-gnueabi-gcc.

• Issue: Errors during compilation.

Solution: Verify your C code for syntax errors and ensure you are using the correct flags in the Makefile.

• Issue: Program does not run on Raspberry Pi.

Solution: Ensure you have transferred the executable correctly and that it has execute permissions. Run chmod +x hello on the Raspberry Pi.

Conclusion

Congratulations! You have successfully cross-compiled a C program for the Raspberry Pi using GCC on Ubuntu. By leveraging a Makefile, you can streamline your build process for future projects. Explore further by adding more features to your C program and experimenting with different libraries.