-ifeq ($(LINUX_VERSION),)
- ifeq ($(KERNEL),2.4)
- LINUX_VERSION:=2.4.34
- LINUX_RELEASE:=1
- LINUX_KERNEL_MD5SUM:=f59665540a7f3351ea416a0dad104b55
- else
- LINUX_VERSION:=2.6.19.2
- LINUX_RELEASE:=1
- LINUX_KERNEL_MD5SUM:=ca0ce8f288e8ae93ac243b568f906bf8
- endif
-endif
-KERNEL:=2.$(word 2,$(subst ., ,$(strip $(LINUX_VERSION))))
+ifeq ($(KERNEL),2.4)
+ LINUX_VERSION?=2.4.35.4
+else
+ LINUX_VERSION?=2.6.21.7
+endif
+LINUX_RELEASE?=1
+
+ifeq ($(LINUX_VERSION),2.4.34)
+ LINUX_KERNEL_MD5SUM:=f59665540a7f3351ea416a0dad104b55
+endif
+ifeq ($(LINUX_VERSION),2.4.35.4)
+ LINUX_KERNEL_MD5SUM:=34066faff3d8c042df1c7600b08b8070
+endif
+ifeq ($(LINUX_VERSION),2.6.21.7)
+ LINUX_KERNEL_MD5SUM:=bc15fad1487336d5dcb0945cd039d8ed
+endif
+ifeq ($(LINUX_VERSION),2.6.23.17)
+ LINUX_KERNEL_MD5SUM:=a0300a393ac91ce9c64bf31522b45e2e
+endif
+ifeq ($(LINUX_VERSION),2.6.24.7)
+ LINUX_KERNEL_MD5SUM:=40a73780d51525d28d36dec852c680c4
+endif
+ifeq ($(LINUX_VERSION),2.6.25.20)
+ LINUX_KERNEL_MD5SUM:=0da698edccf03e2235abc2830a495114
+endif
+ifeq ($(LINUX_VERSION),2.6.26.8)
+ LINUX_KERNEL_MD5SUM:=05dd0d4f8f110b4219ae6ec7a36c046d
+endif
+ifeq ($(LINUX_VERSION),2.6.27.19)
+ LINUX_KERNEL_MD5SUM:=182b23174febe7cc8106dd394f368dee
+endif
+ifeq ($(LINUX_VERSION),2.6.28.7)
+ LINUX_KERNEL_MD5SUM:=72d7d509c1f997e6d043bc9c683d89f1
+endif
+
+# disable the md5sum check for unknown kernel versions
+LINUX_KERNEL_MD5SUM?=x
+
+split_version=$(subst ., ,$(1))
+merge_version=$(subst $(space),.,$(1))
+KERNEL=$(call merge_version,$(wordlist 1,2,$(call split_version,$(LINUX_VERSION))))
+KERNEL_PATCHVER=$(call merge_version,$(wordlist 1,3,$(call split_version,$(LINUX_VERSION))))