create UEFI shell on USB flash drive

Boot Process under UEFI

1. System switched on. The Power On Self Test (POST) is executed.
2. UEFI firmware is loaded. Firmware initializes the hardware required for booting.
3. Firmware reads the boot entries in the firmware's boot manager to determine which UEFI application to be launched and from where (i.e. from which disk and partition).
4. Firmware launches the UEFI application.
   • This could be the Arch kernel itself (since EFISTUB is enabled by default).
   • It could be some other application such as a shell or a graphical boot manager.
   • Or the boot entry could simply be a disk. In this case the firmware looks for an EFI system partition on that disk and tries to run the fallback UEFI application \EFI\BOOT\BOOTX64.EFI (BOOTIA32.EFI on 32-bit systems). This is how UEFI bootable thumb drives work.

If Secure Boot is enabled, the boot process will verify authenticity of the EFI binary by signature.

 

Create UEFI shell on USB flash drive

1. Format your USB stick with FAT32
2. Create this folder structure on the stick: "EFI\BOOT"
3. Download Intel's Tianocore UEFI Shell 1.0 and rename the file to "BOOTX64.EFI"
4. Copy "BOOTX64.EFI" to "EFI\BOOT" on your stick
5. Goto BIOS, change to UEFI boot
6. Plugin in your USB stick, boot and hit F10 to enter the boot menu.
7. Press enter the shell will start. When loaded type "fs0:" to switch to the USB stick file system:
   
8. Do whatever you like