updated readme with note for static and global variables

Author: itzandroidtab

Readme.md renamed to readme.md

@@ -8,6 +8,8 @@ To create a OFL executable you need the following:
 * Way to feed the watchdog if enabled
 * A way to restore modified registers after deinit
 
+Note: When using the flash loader no startup code will run. Make sure to initialize any (non const) static and global variables at runtime as they will not be initialized when loading the flash loader.
+
 ## Stack usage
 In the previous documentation Segger reserved 256 bytes of stack for Open flash loaders. In newer versions the documentation mentions 512 bytes of stack with a fallback to 256 bytes for devices with low amounts of memory (for testing, the linkerscript configures 256 bytes of stack).