How to boot from USB on the Asus T101HA

biosbootusb

I have a Asus Transformer Book T101HA and I am trying to boot a bootable USB stick to dual boot a 2nd operating system (it is currently running Windows 10 as it was out of the box).

When I press ESC on start up to load the boot menu, I only get the following regardless of whether a bootable USB is plugged in or not.

Boot Menu

I have also looked in the BIOS to look at the boot order but the options look very limited compared to others ive seen in the past. There is only on boot option and it can only be set to 'Windows Boot Manager' or 'Disabled' (there is no option for USB). There doesn't appear to be any ability to add new boot options.

Trying to edit boot order in BIOS

Can anybody help me out with a way forward to booting from a USB?

Best Answer

Asus T100 is Intel Bay Trail device and most of those, despite having a 64bit CPU, have IA32 (32bit) EFI firmware. Also feature called Secure Boot is enabled in EFI setup by default and that might block some operating systems from showing up in boot menu. In order to make firmware recognize flash-drive as bootable it needs to be formatted as FAT32 and have signed 32bit operating system loader in EFI/bootia32.efi.

You do not mention which 2nd operating system you are trying to boot so I can only assume it's a Linux distribution. It probably does not show up in menu because:

  • SecureBoot is enabled and EFI/bootia32.efi is not signed by valid key - easiest is to disable SecureBoot in EFI setup (there should be a toggle). Beware that some Windows 10 features (e.g. BitLocker) don't work in that state.

  • 32bit EFI loader is not present on flash-drive at all (this applies for most 64bit Linux distribution Live USBs - e.g. Ubuntu). In that case you will need to compile GRUB for 32bit EFI and place it to proper directory (and also disable SecureBoot, obviously). For Ubuntu, there are ISOs already prepared. You can find them here: http://linuxiumcomau.blogspot.com/2016/10/running-ubuntu-on-intel-bay-trail-and.html (NOTE: those are not official Ubuntu images, have patched kernel to support specific hardware and are not officially supported in any way - please read the information on that page before trying them out.)

This page might give you some hints on getting Linux running on your device (if Linux is case): http://www.jfwhome.com/2014/03/07/perfect-ubuntu-or-other-linux-on-the-asus-transformer-book-t100/

Related Question