add BIOS/UEFI glitch workaround (#4)

README.md

@@ -208,5 +208,18 @@ Pi-KVM OS is based on Arch Linux ARM and contains all required packages and conf
     ```
     And run `make install` again.
 
+
+* **Glitchy/Wrong BIOS resolution**
+
+    On some motherboards, the BIOS may be displayed at a lower resolution, or with some rendering issues/glitches, specially on newer ASUS ones.
+
+    e.g
+
+    <img src="bios_glitch.png" alt="ASUS BIOS glitch" width="400"/>
+
+    This can be solved by enabling **Compatibility Support Module (CSM)** on your BIOS, usually under the **Boot** options.
+
+    If you can't or don't want to enable CSM, you can try connecting a DisplayPort monitor, or a [dummy plug](http://amazon.com/s?k=displayport+dummy+plug).
+
 * If you have any problems or questions, you can contact us using Discord: https://discord.gg/bpmXfz5