kernel: Add kernel specific OBJDUMP

This helps in switching toolchains cleanly for kernel build
between gcc and clang

Currently, some kernels allow building with clang but not all
the distro might use clang as default system compiler but kernel
may demand gcc which is provided via KERNEL_* variables, however
kernel does use OBJCOPY at places during build and it maybe set
to use llvm objcopy when using clang. That should be a deliberate
setting when clang is used for kernel as well, otherwise it should
use binutils provided objcopy

(From OE-Core rev: 17b409f2fd97894e0943d13c2cb0d52abde647e3)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Cc: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes-recipe/kernel-arch.bbclass

@@ -68,9 +68,12 @@ TARGET_LD_KERNEL_ARCH ?= ""
 HOST_LD_KERNEL_ARCH ?= "${TARGET_LD_KERNEL_ARCH}"
 TARGET_AR_KERNEL_ARCH ?= ""
 HOST_AR_KERNEL_ARCH ?= "${TARGET_AR_KERNEL_ARCH}"
+TARGET_OBJCOPY_KERNEL_ARCH ?= ""
+HOST_OBJCOPY_KERNEL_ARCH ?= "${TARGET_OBJCOPY_KERNEL_ARCH}"
 
 KERNEL_CC = "${CCACHE}${HOST_PREFIX}gcc ${HOST_CC_KERNEL_ARCH} -fuse-ld=bfd ${DEBUG_PREFIX_MAP} -fdebug-prefix-map=${STAGING_KERNEL_DIR}=${KERNEL_SRC_PATH} -fdebug-prefix-map=${STAGING_KERNEL_BUILDDIR}=${KERNEL_SRC_PATH}"
 KERNEL_LD = "${CCACHE}${HOST_PREFIX}ld.bfd ${HOST_LD_KERNEL_ARCH}"
 KERNEL_AR = "${CCACHE}${HOST_PREFIX}ar ${HOST_AR_KERNEL_ARCH}"
+KERNEL_OBJCOPY = "${CCACHE}${HOST_PREFIX}objcopy ${HOST_OBJCOPY_KERNEL_ARCH}"
 TOOLCHAIN ?= "gcc"
 

meta/classes-recipe/kernel-devicetree.bbclass

@@ -68,7 +68,7 @@ do_compile:append() {
 
 	for dtbf in ${KERNEL_DEVICETREE}; do
 		dtb=`normalize_dtb "$dtbf"`
-		oe_runmake $dtb CC="${KERNEL_CC} $cc_extra " LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
+		oe_runmake $dtb CC="${KERNEL_CC} $cc_extra " LD="${KERNEL_LD}" OBJCOPY="${KERNEL_OBJCOPY}" ${KERNEL_EXTRA_ARGS}
 	done
 }
 

meta/classes-recipe/kernel-uboot.bbclass

@@ -34,7 +34,7 @@ uboot_prep_kimage() {
 		linux_comp="${FIT_KERNEL_COMP_ALG}"
 	fi
 
-	[ -n "${vmlinux_path}" ] && ${OBJCOPY} -O binary -R .note -R .comment -S "${vmlinux_path}" linux.bin
+	[ -n "${vmlinux_path}" ] && ${KERNEL_OBJCOPY} -O binary -R .note -R .comment -S "${vmlinux_path}" linux.bin
 
 	if [ "${linux_comp}" != "none" ] ; then
 		if [ "${linux_comp}" = "gzip" ] ; then

meta/classes-recipe/kernel-yocto.bbclass

@@ -455,7 +455,7 @@ do_kernel_configme() {
 		bbfatal_log "Could not find configuration queue (${meta_dir}/config.queue)"
 	fi
 
-	CFLAGS="${CFLAGS} ${TOOLCHAIN_OPTIONS}" HOSTCC="${BUILD_CC} ${BUILD_CFLAGS} ${BUILD_LDFLAGS}" HOSTCPP="${BUILD_CPP}" CC="${KERNEL_CC}" LD="${KERNEL_LD}" ARCH=${ARCH} merge_config.sh -O ${B} ${config_flags} ${configs} > ${meta_dir}/cfg/merge_config_build.log 2>&1
+	CFLAGS="${CFLAGS} ${TOOLCHAIN_OPTIONS}" HOSTCC="${BUILD_CC} ${BUILD_CFLAGS} ${BUILD_LDFLAGS}" HOSTCPP="${BUILD_CPP}" CC="${KERNEL_CC}" LD="${KERNEL_LD}" OBJCOPY="${KERNEL_OBJCOPY}" ARCH=${ARCH} merge_config.sh -O ${B} ${config_flags} ${configs} > ${meta_dir}/cfg/merge_config_build.log 2>&1
 	if [ $? -ne 0 -o ! -f ${B}/.config ]; then
 		bberror "Could not generate a .config for ${KMACHINE}-${LINUX_KERNEL_TYPE}"
 		if [ ${KCONF_AUDIT_LEVEL} -gt 1 ]; then
@@ -489,6 +489,7 @@ python do_config_analysis() {
     env['PATH'] = "%s:%s%s" % (d.getVar('PATH'), s, "/scripts/util/")
     env['LD'] = d.getVar('KERNEL_LD')
     env['CC'] = d.getVar('KERNEL_CC')
+    env['OBJCOPY'] = d.getVar('KERNEL_OBJCOPY')
     env['ARCH'] = d.getVar('ARCH')
     env['srctree'] = s
 
@@ -550,6 +551,7 @@ python do_kernel_configcheck() {
     env['PATH'] = "%s:%s%s" % (d.getVar('PATH'), s, "/scripts/util/")
     env['LD'] = d.getVar('KERNEL_LD')
     env['CC'] = d.getVar('KERNEL_CC')
+    env['OBJCOPY'] = d.getVar('KERNEL_OBJCOPY')
     env['ARCH'] = d.getVar('ARCH')
     env['srctree'] = s
 

meta/classes-recipe/kernel.bbclass

@@ -234,7 +234,7 @@ UBOOT_LOADADDRESS ?= "${UBOOT_ENTRYPOINT}"
 # Some Linux kernel configurations need additional parameters on the command line
 KERNEL_EXTRA_ARGS ?= ""
 
-EXTRA_OEMAKE += ' CC="${KERNEL_CC}" LD="${KERNEL_LD}"'
+EXTRA_OEMAKE += ' CC="${KERNEL_CC}" LD="${KERNEL_LD}" OBJCOPY="${KERNEL_OBJCOPY}"'
 EXTRA_OEMAKE += ' HOSTCC="${BUILD_CC}" HOSTCFLAGS="${BUILD_CFLAGS}" HOSTLDFLAGS="${BUILD_LDFLAGS}" HOSTCPP="${BUILD_CPP}"'
 EXTRA_OEMAKE += ' HOSTCXX="${BUILD_CXX}" HOSTCXXFLAGS="${BUILD_CXXFLAGS}" PAHOLE=false'
 

meta/classes-recipe/module.bbclass

@@ -32,6 +32,7 @@ python do_devshell:prepend () {
     os.environ['CC'] = d.getVar('KERNEL_CC')
     os.environ['LD'] = d.getVar('KERNEL_LD')
     os.environ['AR'] = d.getVar('KERNEL_AR')
+    os.environ['OBJCOPY'] = d.getVar('KERNEL_OBJCOPY')
     os.environ['O'] = d.getVar('STAGING_KERNEL_BUILDDIR')
     kbuild_extra_symbols = d.getVar('KBUILD_EXTRA_SYMBOLS')
     if kbuild_extra_symbols:
@@ -45,7 +46,7 @@ module_do_compile() {
 	oe_runmake KERNEL_PATH=${STAGING_KERNEL_DIR}   \
 		   KERNEL_VERSION=${KERNEL_VERSION}    \
 		   CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
-		   AR="${KERNEL_AR}" \
+		   AR="${KERNEL_AR}" OBJCOPY="${KERNEL_OBJCOPY}" \
 	           O=${STAGING_KERNEL_BUILDDIR} \
 		   KBUILD_EXTRA_SYMBOLS="${KBUILD_EXTRA_SYMBOLS}" \
 		   ${MAKE_TARGETS}
@@ -55,7 +56,7 @@ module_do_install() {
 	unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS
 	oe_runmake DEPMOD=echo MODLIB="${D}${nonarch_base_libdir}/modules/${KERNEL_VERSION}" \
 	           INSTALL_FW_PATH="${D}${nonarch_base_libdir}/firmware" \
-	           CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
+	           CC="${KERNEL_CC}" LD="${KERNEL_LD}" OBJCOPY="${KERNEL_OBJCOPY}" \
 	           O=${STAGING_KERNEL_BUILDDIR} \
 	           ${MODULES_INSTALL_TARGET}
 

meta/recipes-kernel/make-mod-scripts/make-mod-scripts_1.0.bb

@@ -27,7 +27,8 @@ EXTRA_OEMAKE += " HOSTCXX="${BUILD_CXX} ${BUILD_CXXFLAGS} ${BUILD_LDFLAGS}" CROS
 do_configure() {
 	unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS
 	for t in prepare scripts_basic scripts; do
-		oe_runmake CC="${KERNEL_CC}" LD="${KERNEL_LD}" AR="${KERNEL_AR}" \
+		oe_runmake CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
+		AR="${KERNEL_AR}" OBJCOPY="${KERNEL_OBJCOPY}" \
 		-C ${STAGING_KERNEL_DIR} O=${STAGING_KERNEL_BUILDDIR} $t
 	done
 }

meta/recipes-kernel/systemtap/systemtap-uprobes_git.bb

@@ -21,12 +21,12 @@ do_compile() {
 	then
 		unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS CC LD CPP
 		oe_runmake CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
-			   AR="${KERNEL_AR}" \
+			   AR="${KERNEL_AR}" OBJCOPY="${KERNEL_OBJCOPY}" \
 			   -C ${STAGING_KERNEL_DIR} scripts
 		oe_runmake KDIR=${STAGING_KERNEL_DIR}   \
 			   M="${S}/runtime/uprobes/" \
 			   CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
-			   AR="${KERNEL_AR}" \
+			   AR="${KERNEL_AR}" OBJCOPY="${KERNEL_OBJCOPY}" \
 			   -C "${S}/runtime/uprobes/"
 	fi
 }