Add cmake command for OpenCL kernel code

The OpenCL kernel gets parsed and copied into a byte array accessible
by a specific header during the cmake configuration step.

We are now adding a special command "make clbin2h" which would generate
this header byte array on demand

libethash-cl/CMakeLists.txt

@@ -5,6 +5,16 @@ bin2h(SOURCE_FILE ethash_cl_miner_kernel.cl
 	VARIABLE_NAME ethash_cl_miner_kernel
 	HEADER_FILE ${CMAKE_CURRENT_BINARY_DIR}/ethash_cl_miner_kernel.h)
 
+#   Add a custom command so that the user can regenerate the header file containing the kernel
+#   code's bytearray by running "make clbin2h"
+	add_custom_target(clbin2h)
+	add_custom_command(TARGET clbin2h
+	PRE_BUILD
+	COMMAND ${CMAKE_COMMAND} -DBIN2H_SOURCE_FILE="${CMAKE_CURRENT_SOURCE_DIR}/ethash_cl_miner_kernel.cl"
+	-DBIN2H_VARIABLE_NAME=ethash_cl_miner_kernel
+	-DBIN2H_HEADER_FILE="${CMAKE_CURRENT_BINARY_DIR}/ethash_cl_miner_kernel.h"
+	-P "${CMAKE_CURRENT_SOURCE_DIR}/bin2h.cmake")
+
 aux_source_directory(. SRC_LIST)
 file(GLOB HEADERS "*.h")