Bad news, i just notice something. when i query setup_var 0x398 for Launch CSM. it's returning 0x00. So i change it to 0x01 using setup_var 0x398 0x1, setup_var2 0x398 0x1, setup_var_3 0x398 0x1. Everytime i restart i query the value, it comes back to 0x00. From the BIOS exe i gave you first time, CSM is enabled by default yes? I'll try to install the BIOS update this time around.
Update: I've already installed the BIOS update. I've confirm BIOS version has changed from BIOS setting page. Launch CSM value is still 0x00. Even though i've changed it to 0x01, when i restart, the values goes back to 0x00.
I changed BIOS lock 0x92 to 0x00 first before attempting to change the Launch CSM value. Change is not persisted regardless.
Well i know my problem now. Thanks Eugene for being so patient guiding me and teaching me new stuff like BIOS setting from efi shell. This is whole new world for me. I'll do some more research in how to change this stuborn Launch CSM value on my laptop.