Add some comments about using kernel dvb-core.

README.md

@@ -1,5 +1,7 @@
 # DDBridge Driver
 
+Device driver for all Digital Devices DVB demodulator and modulator cards.
+
 ### Patches
 We can only accept patches which don't break compilation for older kernels (as far back as 2.6.37).
 
@@ -9,12 +11,23 @@ incompatiblities to this driver package.
 For installation instructions see:
 
 http://support.digital-devices.eu/index.php?article=152
-### Prepare for Building
 
-   TBD
-  
-### Building
 
-   TBD
-  
-  
+To compile against the dvb-core of a current kernel compile with KERNEL_DVB_CORE=y:
+
+make KERNEL_DVB_CORE=y install
+
+This will only work with current mainline kernels.
+
+Some features will also not work correctly with the mainline kernel dvb-core:
+
+- some devices will have fewer delivery systems enumerated
+  if one you need is missing you will have to fix it yourself
+
+- the DTV_INPUT property will not work
+
+- local bugfixes in dvb-core will be missing
+
+- Some device names will be different because they do not exist in the kernel
+
+Also, do not forget to delete old dvb-core modules from e.g. /lib/modules/x.y.z-amd64/updates/ !