reproduce (this is a W=1 build):
        # https://github.com/thierryreding/linux/commit/f5ff652a1c2ce0a75ce86425cbc5f499933c9018
        git remote add thierryreding https://github.com/thierryreding/linux
        git fetch --no-tags thierryreding pmc
        git checkout f5ff652a1c2ce0a75ce86425cbc5f499933c9018
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kernel/cpu/microcode/ kernel/printk/