diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 7f891ebfbd85..34be3247fca4 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -317,7 +317,7 @@ config PPC_BPA
 
 config PPC_OF
 	bool
-	depends on PPC_MULTIPLATFORM	# for now
+	depends on PPC_MULTIPLATFORM || PPC_ISERIES
 	default y
 
 config XICS
@@ -836,7 +836,7 @@ endmenu
 if PPC64
 config KERNEL_START
 	hex
-	default "0xc0000000"
+	default "0xc000000000000000"
 endif
 
 source "net/Kconfig"
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 61653cb60c4e..19df881bf67b 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -55,7 +55,7 @@ config BDI_SWITCH
 
 config BOOTX_TEXT
 	bool "Support for early boot text console (BootX or OpenFirmware only)"
-	depends PPC_OF
+	depends PPC_OF && !PPC_ISERIES
 	help
 	  Say Y here to see progress messages from the boot firmware in text
 	  mode. Requires either BootX or Open Firmware.