2.8. Cross-Compiling Applications

2.8.1. References

• Bootlin slides, chapter Cross-Compiling Toolchains
• Main Buildroot documentation: https://buildroot.uclibc.org/downloads/manual/manual.html

2.8.2. Goals

• Cross-compile an application for the target
• Using the Buildroot cross-compiler and sysroot

2.8.3. Steps

1. Compile a simple C program with the host toolchain, using a Makefile.
2. Adapt the Makefile and compile a simple C program with the toolchain from Buildroot:

user@host: ls -l ${BR_PATH}/output/host/usr/bin

3. Copy the binary to the target and test it (use the simple SD card image from previous lab).

2.8.4. Questions

• Which binaries are present in the toolchain directory?
• Which version of gcc is used?
• Which libc is gcc using?
• Are there other interesting parameters used in the gcc configuration?
• Check the location of the sysroot.
• Show that the generated binary is built for the target architecture using readelf:

user@host: readelf -a <binary>
user@host: readelf -h <binary>