1) Read from Nvram(read_nvram)
   fd = NVM_GetFileDesc(LID, &rec_size, &rec_num, ISWRITE);
   read(fd, &nvram_gpcustom, rec_num*rec_size);
   NVM_CloseFileDesc(gp_custom_fd);
2) Write to device file(write_device)
   device_fd = open("/dev/als_ps", O_RDONLY);
   ioctl(device_io_fd, ALSPS_SET_PS_MODE, &ps_threshold);
3) Nvram agent main()
   void main(int argc, char *argv[])   {
        read_nvram();
        write_device();
   }

LOCAL_PATH := $(my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE_TAGS := eng
LOCAL_SRC_FILES := \
       nvram_customop.c
LOCAL_C_INCLUDES := \
       $(MTK_PATH_SOURCE)/external/nvram/libnvram
LOCAL_PRELINK_MODULE := false 
LOCAL_SHARED_LIBRARIES := \
        libnvram \
        libnativehelper \
        libcutils \
        libutils
 LOCAL_MODULE := nvram_customop
include $(BUILD_EXECUTABLE)

service nvram_daemon /system/bin/nvram_daemon
    user root
    group nvram
    oneshot

service nvram_customop /system/bin/nvram_customop
    user system 
    group system nvram
    oneshot
    disabled
on property:nvram_init=Ready
    start nvram_customop