-ifeq ($(LINUX_VERSION),)
- ifeq ($(KERNEL),2.4)
- LINUX_VERSION:=2.4.33.4
- LINUX_RELEASE:=1
- LINUX_KERNEL_MD5SUM:=aca0257549c385a227088ad8853a72a2
- else
- LINUX_VERSION:=2.6.19.1
- LINUX_RELEASE:=1
- LINUX_KERNEL_MD5SUM:=2ab08fdfddc00e09b3d5bc7397d3c8be
- endif
-endif
-KERNEL:=2.$(word 2,$(subst ., ,$(strip $(LINUX_VERSION))))
+ifeq ($(KERNEL),2.4)
+ LINUX_VERSION?=2.4.37.9
+endif
+LINUX_RELEASE?=1
+
+ifeq ($(LINUX_VERSION),2.4.37.9)
+ LINUX_KERNEL_MD5SUM:=b85b8962840c13f17f944e7b1890f8f8
+endif
+ifeq ($(LINUX_VERSION),2.6.25.20)
+ LINUX_KERNEL_MD5SUM:=0da698edccf03e2235abc2830a495114
+endif
+ifeq ($(LINUX_VERSION),2.6.30.10)
+ LINUX_KERNEL_MD5SUM:=eb6be465f914275967a5602cb33662f5
+endif
+ifeq ($(LINUX_VERSION),2.6.31.12)
+ LINUX_KERNEL_MD5SUM:=517be354b81b780e2f4b2ad614d030de
+endif
+ifeq ($(LINUX_VERSION),2.6.32.8)
+ LINUX_KERNEL_MD5SUM:=82023ede52f067fcc55c5e70b02e48ae
+endif
+
+# disable the md5sum check for unknown kernel versions
+LINUX_KERNEL_MD5SUM?=x
+
+split_version=$(subst ., ,$(1))
+merge_version=$(subst $(space),.,$(1))
+KERNEL_BASE=$(firstword $(subst -, ,$(LINUX_VERSION)))
+KERNEL=$(call merge_version,$(wordlist 1,2,$(call split_version,$(KERNEL_BASE))))
+KERNEL_PATCHVER=$(call merge_version,$(wordlist 1,3,$(call split_version,$(KERNEL_BASE))))