linux-headers

• Provide before musl-headers in stage 1 (toolchain) to prevent overwriting libc headers

Prepare

• mrproper requires ARCH

Package

• headers_install requires rsync and removes kernel headers cmd files by default
• INSTALL_HDR_PATH="$cross"/usr only works with headers_install target (not headers)
• find usr/include ! -name '*.h' -type f -delete removes all .cmd files, .gitignore, headers_check.pl and Makefile
• Remove usr/include/drm to use headers from libdrm

Other

• The headers_check target runs a few trivial sanity checks on the headers before install
  • checks if a header includes something nonexistent
  • checks if the declarations inside the headers are sane
  • checks if kernel internals are leaked into user space
  • not that useful for release tarballs but could come in handy when working with kernel git trees