add criteria for kernel patches

README.md

@@ -3,7 +3,14 @@
 # SONiC - Kernel
 
 ## Description
-This repository contains the scripts and patches to build the kernel for SONiC.
+This repository contains the scripts and patches to build the kernel for SONiC. SONiC uses the same kernel for all platforms. We prefer to out-of-tree kernel platform modules. We accept kernel patches on following conditions:
+
+- Existing kernel modules need to be enabled
+- Existing kernel modules need to be patched and those patches are available in upstream
+- New kernel modules which are common to all platforms
+- Platform specific kernel modules which are impossible or very difficul to be built out of kernel tree
+
+Platform specific kernel modules are expected to develop out-of-tree kernel modules, provide them in debian packages to be embeded into SONiC ONE image and installed on their platforms.
 
 Usage: