# Linux Kernel Module Cheat
The perfect emulation setup to study and develop the <<linux-kernel>> v5.9.2, kernel modules, <<qemu-buildroot-setup,QEMU>>, <<gem5-buildroot-setup,gem5>> and x86_64, ARMv7 and ARMv8 <<userland-assembly,userland>> and <<baremetal-setup,baremetal>> assembly, <<c,ANSI C>>, <<cpp,C++>> and <<posix,POSIX>>. <<gdb>> and <<kgdb>> just work. Powered by <<about-the-qemu-buildroot-setup,Buildroot>> and <<about-the-baremetal-setup,crosstool-NG>>. Highly automated. Thoroughly documented. Automated <<test-this-repo,tests>>.

#### 27.8.3. Eigen

Header only linear algebra library with a mainline Buildroot package:

    ./build-buildroot --config 'BR2_PACKAGE_EIGEN=y'
    ./build-userland --package eigen -- userland/libs/eigen/hello.cpp

Just create an array and print it:

    ./run --eval-after './libs/eigen/hello.out'

Output:

      3  -1
    2.5 1.5

Source: userland/libs/eigen/hello.cpp

This example just creates a matrix and prints it out.

Tested on: a4bdcf102c068762bb1ef26c591fcf71e5907525