diff --git a/openpower/configs/barreleye_defconfig b/openpower/configs/barreleye_defconfig
index e15a22d..1793273 100644
--- a/openpower/configs/barreleye_defconfig
+++ b/openpower/configs/barreleye_defconfig
@@ -14,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
diff --git a/openpower/configs/firenze_defconfig b/openpower/configs/firenze_defconfig
index c83e254..0c9c3c9 100644
--- a/openpower/configs/firenze_defconfig
+++ b/openpower/configs/firenze_defconfig
@@ -13,7 +13,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
diff --git a/openpower/configs/firestone_defconfig b/openpower/configs/firestone_defconfig
index b8a44e2..e08f365 100644
--- a/openpower/configs/firestone_defconfig
+++ b/openpower/configs/firestone_defconfig
@@ -14,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
diff --git a/openpower/configs/garrison_defconfig b/openpower/configs/garrison_defconfig
index 06876af..e399ac2 100644
--- a/openpower/configs/garrison_defconfig
+++ b/openpower/configs/garrison_defconfig
@@ -14,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
diff --git a/openpower/configs/habanero_defconfig b/openpower/configs/habanero_defconfig
index 40a7e4d..8b6d82d 100644
--- a/openpower/configs/habanero_defconfig
+++ b/openpower/configs/habanero_defconfig
@@ -15,7 +15,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
diff --git a/openpower/configs/linux/skiroot_p9_defconfig b/openpower/configs/linux/skiroot_p9_defconfig
index 7b08bae..309f182 100644
--- a/openpower/configs/linux/skiroot_p9_defconfig
+++ b/openpower/configs/linux/skiroot_p9_defconfig
@@ -13,6 +13,7 @@
 CONFIG_TASK_DELAY_ACCT=y
 CONFIG_TASK_XACCT=y
 CONFIG_TASK_IO_ACCOUNTING=y
+# CONFIG_CPU_ISOLATION is not set
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_LOG_BUF_SHIFT=20
@@ -75,6 +76,7 @@
 CONFIG_BLK_DEV_RAM_SIZE=65536
 CONFIG_VIRTIO_BLK=m
 CONFIG_BLK_DEV_NVME=m
+CONFIG_NVME_MULTIPATH=y
 CONFIG_EEPROM_AT24=y
 # CONFIG_CXL is not set
 CONFIG_BLK_DEV_SD=m
@@ -135,6 +137,7 @@
 CONFIG_IXGBE=m
 CONFIG_I40E=m
 CONFIG_MLX4_EN=m
+# CONFIG_MLX4_CORE_GEN2 is not set
 CONFIG_MLX5_CORE=m
 CONFIG_MLX5_CORE_EN=y
 # CONFIG_MLX5_MPFS is not set
@@ -152,6 +155,7 @@
 CONFIG_SERIAL_8250=y
 CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_IPMI_HANDLER=y
+# CONFIG_IPMI_PROC_INTERFACE is not set
 CONFIG_IPMI_DEVICE_INTERFACE=y
 CONFIG_IPMI_POWERNV=y
 CONFIG_HW_RANDOM=y
@@ -159,7 +163,6 @@
 # CONFIG_I2C_COMPAT is not set
 CONFIG_I2C_CHARDEV=y
 # CONFIG_I2C_HELPER_AUTO is not set
-# CONFIG_RC_CORE is not set
 CONFIG_DRM=y
 CONFIG_DRM_RADEON=y
 CONFIG_DRM_AST=m
diff --git a/openpower/configs/openpower_mambo_defconfig b/openpower/configs/openpower_mambo_defconfig
index 3f7e48d..66e0c24 100644
--- a/openpower/configs/openpower_mambo_defconfig
+++ b/openpower/configs/openpower_mambo_defconfig
@@ -11,7 +11,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
diff --git a/openpower/configs/openpower_p9_mambo_defconfig b/openpower/configs/openpower_p9_mambo_defconfig
index b0487bc..1f2e4b4 100644
--- a/openpower/configs/openpower_p9_mambo_defconfig
+++ b/openpower/configs/openpower_p9_mambo_defconfig
@@ -11,7 +11,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
diff --git a/openpower/configs/p9dsu_defconfig b/openpower/configs/p9dsu_defconfig
index 4362939..98e6355 100644
--- a/openpower/configs/p9dsu_defconfig
+++ b/openpower/configs/p9dsu_defconfig
@@ -14,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_p9_defconfig"
diff --git a/openpower/configs/palmetto_defconfig b/openpower/configs/palmetto_defconfig
index 3389caa..f3be7df 100644
--- a/openpower/configs/palmetto_defconfig
+++ b/openpower/configs/palmetto_defconfig
@@ -13,7 +13,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_defconfig"
diff --git a/openpower/configs/pseries_defconfig b/openpower/configs/pseries_defconfig
index e27136f..9c3ff98 100644
--- a/openpower/configs/pseries_defconfig
+++ b/openpower/configs/pseries_defconfig
@@ -14,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/pseries_skiroot_defconfig"
diff --git a/openpower/configs/romulus_defconfig b/openpower/configs/romulus_defconfig
index 5920e3e..401a516 100644
--- a/openpower/configs/romulus_defconfig
+++ b/openpower/configs/romulus_defconfig
@@ -14,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_p9_defconfig"
@@ -41,7 +41,7 @@
 BR2_OPENPOWER_POWER9=y
 BR2_HOSTBOOT_CONFIG_FILE="romulus.config"
 BR2_OPENPOWER_MACHINE_XML_GITHUB_PROJECT_VALUE="romulus-xml"
-BR2_OPENPOWER_MACHINE_XML_VERSION="b788f99848d65192bbb76aa76ab456a5792f4315"
+BR2_OPENPOWER_MACHINE_XML_VERSION="dbebf6c151618c3e2d40b5cab5a8a53d07e62e62"
 BR2_OPENPOWER_MACHINE_XML_FILENAME="romulus.xml"
 BR2_OPENPOWER_SYSTEM_XML_FILENAME="ROMULUS_hb.system.xml"
 BR2_OPENPOWER_MRW_XML_FILENAME="ROMULUS_hb.mrw.xml"
diff --git a/openpower/configs/witherspoon_defconfig b/openpower/configs/witherspoon_defconfig
index 1e0e7b0..f534215 100644
--- a/openpower/configs/witherspoon_defconfig
+++ b/openpower/configs/witherspoon_defconfig
@@ -1,6 +1,5 @@
 BR2_powerpc64le=y
 BR2_powerpc_power8=y
-BR2_GLOBAL_PATCH_DIR="$(BR2_EXTERNAL_OP_BUILD_PATH)/patches/witherspoon-patches"
 BR2_BINUTILS_EXTRA_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
 BR2_EXTRA_GCC_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
 BR2_TOOLCHAIN_BUILDROOT_CXX=y
@@ -15,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_p9_defconfig"
diff --git a/openpower/configs/zaius_defconfig b/openpower/configs/zaius_defconfig
index a09716c..524902a 100644
--- a/openpower/configs/zaius_defconfig
+++ b/openpower/configs/zaius_defconfig
@@ -1,6 +1,5 @@
 BR2_powerpc64le=y
 BR2_powerpc_power8=y
-BR2_GLOBAL_PATCH_DIR="$(BR2_EXTERNAL_OP_BUILD_PATH)/patches/zaius-patches"
 BR2_BINUTILS_EXTRA_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
 BR2_EXTRA_GCC_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
 BR2_TOOLCHAIN_BUILDROOT_CXX=y
@@ -15,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_p9_defconfig"
diff --git a/openpower/configs/zz_defconfig b/openpower/configs/zz_defconfig
index f78a43f..42b1764 100644
--- a/openpower/configs/zz_defconfig
+++ b/openpower/configs/zz_defconfig
@@ -13,7 +13,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var ../openpower/scripts/firmware-whitelist"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.14.20"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.15.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL_OP_BUILD_PATH)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_OP_BUILD_PATH)/configs/linux/skiroot_p9_defconfig"