llkm-cross-arm64

Test loadable linux kernel module cross-compilation for arm64 at x86_64 Linux machine

Work platform:

# uname -a
Linux maxim 4.15.0-36-lowlatency #39-Ubuntu SMP PREEMPT Tue Sep 25 00:16:08 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

Install cross-compiler toolchain:

# sudo apt install -y gcc-7-aarch64-linux-gnu
# sudo ln -s /usr/bin/aarch64-linux-gnu-gcc-7 /usr/bin/aarch64-linux-gnu-gcc

Setup linux headers for arm64 arch:

# cd /usr/src/linux-headers-$(shell uname -r)
# sudo make ARCH=arm64 oldconfig
# sudo make ARCH=arm64 prepare
# sudo make ARCH=arm64 headers_check
# sudo make ARCH=arm64 headers_install
# sudo make ARCH=arm64 scripts

Go back to test module sources and make:

# make CROSS=/usr/bin/aarch64-linux-gnu-

Check:

# file hello.ko
hello.ko: ELF 64-bit LSB relocatable, ARM aarch64, version 1 (SYSV), BuildID[sha1]=2bd5a6a6b436899ee635ee7f44e8d4e97e3019e5, not stripped