linux-kernel: Build only one kernel per platform

With this change we are building the same kernel config for all
hardwares belonging to the same platform. The configs only differ from
one or two drivers which are enabled or not and they are anyway not
loaded as long as the devicetree is not matching.

But having only one config for several hardwares is reducing maintenance
(like enabling or disabling kernel security features) and also reducing
build time when building for different machines.

BugzID: 75223

conf/machine/am335x-hw25.conf

@@ -7,7 +7,7 @@ MACHINEOVERRIDES .= ":am335x-nmhw24"
 
 UBOOT_MACHINE = "am335x_hw25_defconfig"
 
-KERNEL_DEVICETREE = "am335x-hw25.dtb "
+KERNEL_DEVICETREE_TO_USE = "${HW25_DT}"
 
 SERIAL_CONSOLES = "115200;ttyS0"
 DEFAULT_ETH = "lan0"

conf/machine/am335x-hw26.conf

@@ -4,7 +4,7 @@
 
 #require conf/machine/include/ti33x.inc
 require am335x-nmhw21.conf
-KERNEL_DEVICETREE = "am335x-hw26.dtb "
+KERNEL_DEVICETREE_TO_USE = "${HW26_DT}"
 MACHINEOVERRIDES .= ":am335x-nmhw21"
 MACHINE_FEATURES += "pps"
 MACHINE_FEATURES_remove = "user-module"

conf/machine/am335x-nmhw21.conf

@@ -6,11 +6,7 @@ require conf/machine/include/ti33x.inc
 
 MACHINE_EXTRA_RRECOMMENDS = " kernel-modules kernel-devicetree"
 
-KERNEL_DEFCONFIG ??= "am335x-nmhw21_defconfig"
+KERNEL_DEVICETREE_TO_USE = "${HW21_DT}"
-KERNEL_DEVICETREE = "am335x-nmhw21-prod1.dtb \
-    "
-
-KERNEL_IMAGETYPE = "zImage"
 
 PREFERRED_PROVIDER_virtual/bootloader = "u-boot-ti33x"
 UBOOT_MACHINE = "am335x_nmhw21_defconfig"

conf/machine/am335x-nmhw24.conf

@@ -6,11 +6,7 @@ require conf/machine/include/ti33x.inc
 
 MACHINE_EXTRA_RRECOMMENDS = " kernel-modules kernel-devicetree"
 
-KERNEL_DEFCONFIG ??= "am335x-nmhw24_defconfig"
+KERNEL_DEVICETREE_TO_USE = "${HW24_DT}"
-KERNEL_DEVICETREE = "am335x-nmhw24-prod1.dtb \
-    "
-
-KERNEL_IMAGETYPE = "zImage"
 
 PREFERRED_PROVIDER_virtual/bootloader = "u-boot-ti33x"
 UBOOT_MACHINE = "am335x_nrhw24_defconfig"

conf/machine/am335x-nrhw16.conf

@@ -6,14 +6,7 @@ require conf/machine/include/ti33x.inc
 
 MACHINE_EXTRA_RRECOMMENDS = " kernel-modules kernel-devicetree"
 
-KERNEL_DEFCONFIG ??= "am335x-nrhw16_defconfig"
+KERNEL_DEVICETREE_TO_USE = "${HW16_DT}"
-KERNEL_DEVICETREE = "am335x-nrhw16.dtb \
-    am335x-nrhw16-prod2.dtb \
-    am335x-nrhw16-prod3.dtb \
-    am335x-nrhw16-prod4.dtb \
-    am335x-nrhw16-prod5.dtb \
-    "
-KERNEL_IMAGETYPE = "zImage"
 
 PREFERRED_PROVIDER_virtual/bootloader = "u-boot-ti33x"
 UBOOT_MACHINE = "am335x_nbhw16_v2_defconfig"

conf/machine/am335x-nrhw20.conf

@@ -6,10 +6,7 @@ require conf/machine/include/ti33x.inc
 
 MACHINE_EXTRA_RRECOMMENDS = " kernel-modules kernel-devicetree"
 
-KERNEL_DEFCONFIG ??= "am335x-nrhw20_defconfig"
+KERNEL_DEVICETREE_TO_USE = "${HW20_DT}"
-KERNEL_DEVICETREE = "am335x-nrhw20-prod1.dtb \
-    "
-KERNEL_IMAGETYPE = "zImage"
 
 PREFERRED_PROVIDER_virtual/bootloader = "u-boot-ti33x"
 UBOOT_MACHINE = "am335x_nrhw20_defconfig"

conf/machine/include/ti33x.inc

@@ -45,3 +45,25 @@ MACHINE_FEATURES = "kernel26 apm usbgadget usbhost pci vfat ext2 screen alsa eth
 NM_TARGET = "netbird"
 NM_ARCH = "arm"
 MACHINEOVERRIDES =. "${NM_TARGET}:"
+
+
+# We have one kernel for all TI machines
+KERNEL_IMAGETYPE = "zImage"
+KERNEL_DEFCONFIG = "am335x-netmodule_defconfig"
+STAGING_KERNEL_DIR = "${TMPDIR}/work-shared/${TUNE_PKGARCH}/kernel-source"
+STAGING_KERNEL_BUILDDIR = "${TMPDIR}/work-shared/${TUNE_PKGARCH}/kernel-build-artifacts"
+
+# We need to specify all devicetrees here in order to build them with the kernel
+HW16_DT = "am335x-nrhw16.dtb \
+    am335x-nrhw16-prod2.dtb \
+    am335x-nrhw16-prod3.dtb \
+    am335x-nrhw16-prod4.dtb \
+    am335x-nrhw16-prod5.dtb \
+    "
+HW20_DT = "am335x-nrhw20-prod1.dtb"
+HW21_DT = "am335x-nmhw21-prod1.dtb"
+HW24_DT = "am335x-nmhw24-prod1.dtb"
+HW25_DT = "am335x-hw25.dtb"
+HW26_DT = "am335x-hw26.dtb"
+
+KERNEL_DEVICETREE = "${HW16_DT} ${HW20_DT} ${HW21_DT} ${HW24_DT} ${HW25_DT} ${HW26_DT}"

recipes-kernel/linux/linux-netmodule_git.bb

@@ -18,6 +18,9 @@ SRC_URI_append_netbird = " file://wlan.cfg"
 
 SRCREV ?= "${AUTOREV}"
 
+# We are building one kernel for all machines with the same architecture
+PACKAGE_ARCH = "${TUNE_PKGARCH}"
+
 # HW23 is using a different source
 SRC_URI_imx8-nmhw23 = "git://git.netmodule.intranet/yoctoproject/linux-netmodule.git;protocol=ssh;user=gitea;branch=4.14/nxp/nmhw23"
 LIC_FILES_CHKSUM_imx8-nmhw23 = "file://COPYING;md5=d7810fab7487fb0aad327b76f1be7cd7"

recipes-kernel/linux/netmodule-fitimage.bb

@@ -26,6 +26,8 @@ INITRAMFS_IMAGE_NAME ?= "${INITRAMFS_IMAGE}-${MACHINE}"
 
 UBOOT_LOADADDRESS ?= "${UBOOT_ENTRYPOINT}"
 
+KERNEL_DEVICETREE = "${KERNEL_DEVICETREE_TO_USE}"
+
 do_configure_prepend () {
 	install -d ${S}/arch/${ARCH}/boot/
 	for DTB in ${KERNEL_DEVICETREE}; do