Update Hardware Button page

docs/helios64/button.md

@@ -1,42 +1,26 @@
-## Onboard Button
+## On-board Button
 
-![!Button location](img/button/button_location.jpg)
+![Helios64 Button](img/button/helios64_button.jpg)
+
+!!! note
+    All these on-board buttons are also exposed on the [Front Panel](/helios64/front-panel).
 
 ### Power Button
 
-Helios64 board provides a POWER push button (PWR BTN) to power on/off the system.
-This button is connected to PMIC RK808-D.
+Helios64 board provides a POWER push button (SW1) to power ON/OFF the system. This button is connected to Power Management IC (PMIC) RK808-D. The following actions can be performed:
 
-Short press (~1 second) will turn on the system when the current state is power off. On Linux, this will inform kernel to perform gracefull shutdown.
-
-Long press (~4 seconds **TBC**) will signals PMIC to cut off the power in case of system not responding (Force power off).
-
-This button also routed to Front Panel, so user don't need to open the case to power on/off the system.
+* **Power ON** : Short press (~1 second) will turn on the system when the current state is power off.
+* **Power OFF** : Short press (~1 second) will inform system to perform graceful shutdown when the system is on.
+* **Force Power OFF** : Long press (~4 seconds) will signals PMIC to cut off the power in case of system not responding.
 
 ### Reset Button
 
-Helios64 board provides a RESET push button (RST BTN) to hard reset the board.
-
-This button also routed to Front Panel, so user don't need to open the case to hard reset the system.
+Helios64 board provides a RESET push button (SW3) to hard reset the system.
 
 ### Recovery Button
 
-User can enter recovery mode by pressing this button during boot up (bootloader stage). U-Boot will read this button and switch the USB type C into USB Mass Storage device with eMMC as the storage.
-User then can use Balena Etcher or dd to write OS image into eMMC.
+Helios64 board provides a RECOVERY push button (SW2) to allow user to easily flash over USB the on-board eMMC storage. This can be useful if you want to do a fresh install or if you want to repair a system that doesn't boot anymore.
 
-On Linux, this button behave as user button and when pressed will emit **BTN_0** keycode.
+User can enter recovery mode by pressing this button during boot up (bootloader stage). U-Boot will read the button state and switch the USB type-C port into USB Mass Storage device to expose eMMC flash as storage device. User can then use flash tools to write new OS image into eMMC flash.
 
-This button also routed to Front Panel, so user don't need to open the case to enter Recovery Mode.
-
-
-## Front Panel Button
-
-For button location on front panel please refer to [Front Panel](/helios64/front-panel/#the-front-panel-description).
-
-### USR2 Button
-
-There is additional user button on Front Panel board located on [P2](/helios64/front-panel/#wiring-diagram). On Linux, this button when pressed will emit **BTN_1** keycode.
-
-
-## References
-[input-event-codes.h](https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/plain/include/uapi/linux/input-event-codes.h)
+Under Linux, this button behaves as user button and when pressed will emit **BTN_0** keycode (refer to [Linux Input Codes](https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/plain/include/uapi/linux/input-event-codes.h)). Therefore this button can also be used to trigger other actions than recovery.