Compile and run GNU-EFI applications under linux

Requirements :

Download gnu-efi from here : https://sourceforge.net/projects/gnu-efi/

gcc-3.0 or newer

	gcc --version

A version of objcopy that supports EFI applications :

	objcopy --help

Check if supported target contains elf64-x86-64 elf32-i386 elf32-x86-64

mtools : Utilities to access MS-DOS disks from Linux

Compile and install GNU-EFI Library:

Go to gnu-efi source folder

	make
	make install

Compile GNU-EFI application :

Use this makefile to easily compile and run gnu-efi application. It will recursively compile all c files in the sub-directories. Change the following macros to locate the libraries and headers installed on the previous step.

```makefile
IMAGE		= uefi_app 
TARGET		= main.efi 

INCDIR		= /usr/local/include
LIBDIR		= /usr/local/lib
EFILIB		= /usr/local/lib
```

Run on qemu :

Locate OVMF in Makefile:

To run the compiled application in qemu we need OVMF for UEFI emulation. OVMF is a port of Intel's tianocore firmware to the qemu virtual machine. Download it from here. makefile OVMF_DIR = ../OVMF Change the OVMF directory in the makefile.

Create Image :

```bash
	make img
```

It will do the following tasks :

	# Create a new image file that will contain the GNU-EFI application. 
	dd if=/dev/zero of=$(IMAGE).img bs=512 count=93750
	# mformat to format it with FAT16.
	mformat -i $(IMAGE).img -h 32 -t 32 -n 64 -c 1 ::
	# Create directory
	mmd -i $(IMAGE).img ::/EFI
	mmd -i $(IMAGE).img ::/EFI/BOOT
	# Copy image
	mcopy -i $(IMAGE).img $(TARGET) ::/EFI/BOOT
	# Copy the nsh script to load efi application automatically from fs0
	mcopy -i $(IMAGE).img startup.nsh ::

Run :

	make run

Running on real hardware :

Format a pendrive with FAT32 file system.
Create /efi/boot/ folders in the pendrive
Rename main.efi to bootx64.efi for 64 bit and bootia32.efi for 32 bit application.
For 64 bit application the pendrive should look like this : /efi/boot/bootx64.efi
For 32 bit application the pendrive should look like this : /efi/boot/bootia32.efi

2.3 KiB Raw Blame History