-GENERIC_LINUX_CONFIG?=$(firstword $(wildcard $(GENERIC_PLATFORM_DIR)/config-$(KERNEL_PATCHVER) $(GENERIC_PLATFORM_DIR)/config-default))
-LINUX_CONFIG?=$(firstword $(wildcard $(foreach subdir,$(PLATFORM_DIR) $(PLATFORM_SUBDIR),$(subdir)/config-$(KERNEL_PATCHVER) $(subdir)/config-default)) $(PLATFORM_DIR)/config-$(KERNEL_PATCHVER))
-LINUX_SUBCONFIG?=$(if $(SHARED_LINUX_CONFIG),,$(firstword $(wildcard $(PLATFORM_SUBDIR)/config-$(KERNEL_PATCHVER) $(PLATFORM_SUBDIR)/config-default)))
-ifeq ($(LINUX_CONFIG),$(LINUX_SUBCONFIG))
- LINUX_SUBCONFIG:=
+__config_name_list = $(1)/config-$(KERNEL_PATCHVER) $(1)/config-default
+__config_list = $(firstword $(wildcard $(call __config_name_list,$(1))))
+find_kernel_config=$(if $(__config_list),$(__config_list),$(lastword $(__config_name_list)))
+
+GENERIC_LINUX_CONFIG = $(call find_kernel_config,$(GENERIC_PLATFORM_DIR))
+LINUX_TARGET_CONFIG = $(call find_kernel_config,$(PLATFORM_DIR))
+ifneq ($(PLATFORM_DIR),$(PLATFORM_SUBDIR))
+ LINUX_SUBTARGET_CONFIG = $(call find_kernel_config,$(PLATFORM_SUBDIR))
+endif
+
+# config file list used for compiling
+LINUX_KCONFIG_LIST = $(wildcard $(GENERIC_LINUX_CONFIG) $(LINUX_TARGET_CONFIG) $(LINUX_SUBTARGET_CONFIG) $(TOPDIR)/env/kernel-config)
+
+# default config list for reconfiguring
+# defaults to subtarget if subtarget exists and target does not
+# defaults to target otherwise
+USE_SUBTARGET_CONFIG = $(if $(wildcard $(LINUX_TARGET_CONFIG)),,$(if $(LINUX_SUBTARGET_CONFIG),1))
+
+LINUX_RECONFIG_LIST = $(wildcard $(GENERIC_LINUX_CONFIG) $(LINUX_TARGET_CONFIG) $(if $(USE_SUBTARGET_CONFIG),$(LINUX_SUBTARGET_CONFIG)))
+LINUX_RECONFIG_TARGET = $(if $(USE_SUBTARGET_CONFIG),$(LINUX_SUBTARGET_CONFIG),$(LINUX_TARGET_CONFIG))
+
+# select the config file to be cahnged by kernel_menuconfig/kernel_oldconfig
+ifeq ($(CONFIG_TARGET),platform)
+ LINUX_RECONFIG_LIST = $(wildcard $(GENERIC_LINUX_CONFIG) $(LINUX_TARGET_CONFIG))
+ LINUX_RECONFIG_TARGET = $(LINUX_TARGET_CONFIG)