-GENERIC_PLATFORM_DIR := $(TOPDIR)/target/linux/generic-$(KERNEL)
-GENERIC_PATCH_DIR := $(GENERIC_PLATFORM_DIR)/patches$(shell [ -d "$(GENERIC_PLATFORM_DIR)/patches-$(KERNEL_PATCHVER)" ] && printf -- "-$(KERNEL_PATCHVER)" || true )
+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))