Merge pull request #57 from ARMmbed/portability-improvements-documentation

Portability improvements documentation

Author: meriac

README.md

@@ -56,7 +56,7 @@ On OS X [st-flash](https://github.com/texane/stlink) is available via `brew inst
 
 Hit the reset button after flashing to start program execution. The application starts running right after you reset the processor. When the blue (K64F) or green (STM32F4) LED blinks with a 1s period, it means that the program is simply comparing the password with the challenge, the comparison is not successful and it is ready to try again.
 
-If you press the on-board push-button (`SW2` on the K64F, `USER` on the STM32F4), you trigger an interrupt service routine that tries to read the secret from the (leaked) secure box context pointer. If the read is successful the same LED starts blinking faster (a period of 200ms). If the uVisor captures the denied access, the system halts and the red LED blinks (`PERMISSION_DENIED` error code). On the K64F do not use `SW3`, as it triggers a non-maskable interrupt, which is currently unsupported and results in a halt with a `NOT_ALLOWED` error code.
+If you press the on-board push-button (`SW2` on the K64F, `USER` on the STM32F4), or wait 10 seconds, a routine runs that tries to read the secret from the secure box. If the read is successful the same LED starts blinking faster (a period of 200ms). If the uVisor captures the denied access, the system halts and the red LED blinks (`PERMISSION_DENIED` error code). On the K64F do not use `SW3`, as it triggers a non-maskable interrupt, which is currently unsupported and results in a halt with a `NOT_ALLOWED` error code.
 
 ### Debugging