Linux From Scratch - Version r12.2-51-systemd

Chapter 5. Compiling a Cross-Toolchain

5.4. Linux-6.12.5 API Headers

The Linux API Headers (in linux-6.12.5.tar.xz) expose the kernel's API for use by Glibc.

Approximate build time: less than 0.1 SBU
Required disk space: 1.6 GB

5.4.1. Installation of Linux API Headers

The Linux kernel needs to expose an Application Programming Interface (API) for the system's C library (Glibc in LFS) to use. This is done by way of sanitizing various C header files that are shipped in the Linux kernel source tarball.

Make sure there are no stale files embedded in the package: 

make mrproper

Now extract the user-visible kernel headers from the source. The recommended make target “headers_install” cannot be used, because it requires rsync, which may not be available. The headers are first placed in ./usr, then copied to the needed location. 

make headers
find usr/include -type f ! -name '*.h' -delete
cp -rv usr/include $LFS/usr

5.4.2. Contents of Linux API Headers

Installed headers: /usr/include/asm/*.h, /usr/include/asm-generic/*.h, /usr/include/drm/*.h, /usr/include/linux/*.h, /usr/include/misc/*.h, /usr/include/mtd/*.h, /usr/include/rdma/*.h, /usr/include/scsi/*.h, /usr/include/sound/*.h, /usr/include/video/*.h, and /usr/include/xen/*.h
Installed directories: /usr/include/asm, /usr/include/asm-generic, /usr/include/drm, /usr/include/linux, /usr/include/misc, /usr/include/mtd, /usr/include/rdma, /usr/include/scsi, /usr/include/sound, /usr/include/video, and /usr/include/xen

Short Descriptions

/usr/include/asm/*.h

The Linux API ASM Headers

/usr/include/asm-generic/*.h

The Linux API ASM Generic Headers

/usr/include/drm/*.h

The Linux API DRM Headers

/usr/include/linux/*.h

The Linux API Linux Headers

/usr/include/misc/*.h

The Linux API Miscellaneous Headers

/usr/include/mtd/*.h

The Linux API MTD Headers

/usr/include/rdma/*.h

The Linux API RDMA Headers

/usr/include/scsi/*.h

The Linux API SCSI Headers

/usr/include/sound/*.h

The Linux API Sound Headers

/usr/include/video/*.h

The Linux API Video Headers

/usr/include/xen/*.h

The Linux API Xen Headers