[PATCH v4 1/3] linux-custom: Split up binaries from kernel headers to kbuild package

[Stefan Koch <stefan-koch@siemens.com>]

This patch does introduce specific kernel kbuild packages that
ship the "scripts" and "tools" binaries.
The kernel headers fulfill this using symlinks to point
to the "scripts" and "tools" of the kernel kbuild package.

This is already known from debian kernel packages structure:
- Generate a kernel headers package without binaries
- Create kernel kbuild packages that
  ship the "scripts" and "tools" binaries
- Using symlinks to point to the "scripts"
  and "tools" binaries

Signed-off-by: Stefan Koch <stefan-koch@siemens.com>
---
 .../linux/files/debian/control.tmpl           |  9 +++-
 .../linux/files/debian/isar/common.tmpl       |  2 +
 .../linux/files/debian/isar/install.tmpl      | 51 +++++++++++++++----
 meta/recipes-kernel/linux/linux-custom.inc    |  4 ++
 4 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/meta/recipes-kernel/linux/files/debian/control.tmpl b/meta/recipes-kernel/linux/files/debian/control.tmpl
index dd0b6245..b19ca2c9 100644
--- a/meta/recipes-kernel/linux/files/debian/control.tmpl
+++ b/meta/recipes-kernel/linux/files/debian/control.tmpl
@@ -26,7 +26,7 @@ Section: devel
 Provides: linux-kernel-headers
 Architecture: any
 Description: Linux support headers for userspace development
- This package provides userspaces headers from the Linux kernel.  These headers
+ This package provides userspaces headers from the Linux kernel. These headers
  are used by the installed headers for GNU glibc and other system libraries.
 
 Package: linux-image-${KERNEL_NAME_PROVIDED}-dbg
@@ -35,3 +35,10 @@ Architecture: any
 Description: Linux kernel debugging symbols for @KR@
  This package will come in handy if you need to debug the kernel. It provides
  all the necessary debug symbols for the kernel and its modules.
+
+Package: linux-kbuild-${KERNEL_NAME_PROVIDED}
+Architecture: any
+Depends: ${perl:Depends}, ${shlib:Depends}
+Description: ${KERNEL_NAME_PROVIDED} Linux kbuild scripts and tools for @KR@
+ This package provides kernel kbuild scripts and tools for @KR@
+ This is useful for people who need to build external modules
diff --git a/meta/recipes-kernel/linux/files/debian/isar/common.tmpl b/meta/recipes-kernel/linux/files/debian/isar/common.tmpl
index 52ebebb0..f4c0519f 100644
--- a/meta/recipes-kernel/linux/files/debian/isar/common.tmpl
+++ b/meta/recipes-kernel/linux/files/debian/isar/common.tmpl
@@ -9,6 +9,7 @@ ARCH=${KERNEL_ARCH}
 KERNEL_PKG_IMAGE=linux-image-${KERNEL_NAME_PROVIDED}
 KERNEL_PKG_KERN_HEADERS=linux-headers-${KERNEL_NAME_PROVIDED}
 KERNEL_PKG_LIBC_HEADERS=linux-libc-dev
+KERNEL_PKG_KERN_KBUILD=linux-kbuild-${KERNEL_NAME_PROVIDED}
 
 # Constants
 KCONF=.config
@@ -19,6 +20,7 @@ deb_img_dir=${deb_top_dir}/${KERNEL_PKG_IMAGE}
 deb_dbg_dir=${deb_img_dir}-dbg
 deb_kern_hdr_dir=${deb_top_dir}/${KERNEL_PKG_KERN_HEADERS}
 deb_libc_hdr_dir=${deb_top_dir}/${KERNEL_PKG_LIBC_HEADERS}
+deb_kern_kbuild_dir=${deb_top_dir}/${KERNEL_PKG_KERN_KBUILD}
 
 # Array of packages to be generated
 declare -A kern_pkgs
diff --git a/meta/recipes-kernel/linux/files/debian/isar/install.tmpl b/meta/recipes-kernel/linux/files/debian/isar/install.tmpl
index 8a604e45..236b67c4 100644
--- a/meta/recipes-kernel/linux/files/debian/isar/install.tmpl
+++ b/meta/recipes-kernel/linux/files/debian/isar/install.tmpl
@@ -33,6 +33,7 @@ do_install() {
     # Trace what we do here
     set -x
 
+    # Run the install steps
     install_image
     if [ "${ARCH}" != "um" ]; then
         install_config
@@ -43,6 +44,10 @@ do_install() {
     install_kmods
     install_headers
 
+    # Cleanup and install kernel scripts and tools
+    rm -rf ${deb_kern_kbuild_dir}
+    install_kbuild ${deb_kern_kbuild_dir}
+
     # Stop tracing
     set +x
 }
@@ -168,21 +173,15 @@ kernel_headers() {
     mkdir -p ${destdir}
     mkdir -p ${deb_kern_hdr_dir}/lib/modules/${krel}
 
-    (cd ${S}; find . -name 'Makefile*' -o -name 'Kconfig*' -o -name '*.pl') >>${src_hdr_files}
-    (cd ${S}; find arch/*/include include scripts -type f -o -type l) >>${src_hdr_files}
+    (cd ${S}; find . -not -path './scripts/*' -a -not -path './tools/*' -a \( -name 'Makefile*' -o -name 'Kconfig*' -o -name '*.pl' \)) >>${src_hdr_files}
+    (cd ${S}; find arch/*/include include -type f -o -type l) >>${src_hdr_files}
     (cd ${S}; find arch/${ARCH} -name module.lds -o -name Kbuild.platforms -o -name Platform) >>${src_hdr_files}
     (cd ${S}; find $(find arch/${ARCH} -name include -o -name scripts -type d) -type f) >>${src_hdr_files}
 
     if [ -n "${CONFIG_MODULES}" ]; then
         echo Module.symvers >> ${obj_hdr_files}
     fi
-    (cd ${O}; find arch/${ARCH}/include include scripts -type f) >>${obj_hdr_files}
-    if [ -n "${CONFIG_STACK_VALIDATION}" -o -n "${CONFIG_HAVE_OBJTOOL}" ]; then
-        (cd ${O}; find tools/objtool -type f -executable) >>${obj_hdr_files}
-    fi
-    if [ -n "${CONFIG_GCC_PLUGINS}" ]; then
-        (cd ${O}; find scripts/gcc-plugins -name *.so -o -name gcc-common.h) >>${obj_hdr_files}
-    fi
+    (cd ${O}; find arch/${ARCH}/include include -type f) >>${obj_hdr_files}
 
     # deploy files that were matched above
     tar -C ${S} -cf - -T - <${src_hdr_files} | tar -C ${destdir} -xf -
@@ -191,8 +190,11 @@ kernel_headers() {
     # add the kernel config
     cp ${O}/${KCONF} ${destdir}/.config
 
-    # handle kernel development tools
-    kernel_tools
+    # add symlink to scripts and tools directories
+    ln -sf ../../lib/linux-kbuild-${krel}/scripts ${destdir}/scripts
+    if [ -n "${CONFIG_STACK_VALIDATION}" -o -n "${CONFIG_HAVE_OBJTOOL}" ]; then
+        ln -sf ../../lib/linux-kbuild-${krel}/tools ${destdir}/tools
+    fi
 
     # create symlinks
     ln -sf /${kernel_headers_dir} ${deb_kern_hdr_dir}/lib/modules/${krel}/build
@@ -206,4 +208,31 @@ install_headers() {
     kernel_headers
 }
 
+install_kbuild() {
+    kernel_kbuild_dir=usr/lib/linux-kbuild-${krel}
+    destdir=${1}/${kernel_kbuild_dir}
+    src_kbuild_files=$(mktemp)
+    obj_kbuild_files=$(mktemp)
+
+    mkdir -p ${destdir}
+
+    (cd ${S}; find . -path './scripts/*' -a -path './tools/*' -a \( -name 'Makefile*' -o -name 'Kconfig*' -o -name '*.pl' \)) >>${src_kbuild_files}
+    (cd ${S}; find scripts -type f -o -type l) >>${src_kbuild_files}
+
+    (cd ${O}; find scripts -type f) >>${obj_kbuild_files}
+    if [ -n "${CONFIG_STACK_VALIDATION}" -o -n "${CONFIG_HAVE_OBJTOOL}" ]; then
+        (cd ${O}; find tools/objtool -type f -executable) >>${obj_kbuild_files}
+    fi
+    if [ -n "${CONFIG_GCC_PLUGINS}" ]; then
+        (cd ${O}; find scripts/gcc-plugins -name *.so -o -name gcc-common.h) >>${obj_kbuild_files}
+    fi
+
+    # deploy files that were matched above
+    tar -C ${S} -cf - -T - <${src_kbuild_files} | tar -C ${destdir} -xf -
+    tar -C ${O} -cf - -T - <${obj_kbuild_files} | tar -C ${destdir} -xf -
+
+    # handle kernel development tools
+    kernel_tools
+}
+
 main install ${*}
diff --git a/meta/recipes-kernel/linux/linux-custom.inc b/meta/recipes-kernel/linux/linux-custom.inc
index 8b367a2f..94ed84a2 100644
--- a/meta/recipes-kernel/linux/linux-custom.inc
+++ b/meta/recipes-kernel/linux/linux-custom.inc
@@ -100,6 +100,10 @@ python() {
     kernel_name = d.getVar("KERNEL_NAME_PROVIDED")
     d.setVar('PROVIDES', 'linux-image-' + kernel_name + ' ' + \
                          'linux-headers-' + kernel_name)
+    headers_depends = "linux-kbuild-" + kernel_name
+
+    # Set dependency for kernel headers
+    d.appendVar("KERNEL_HEADERS_DEBIAN_DEPENDS", headers_depends)
 }
 
 def get_kernel_arch(d):
-- 
2.39.2