Making a UEFI bootable iPXE USB drive

make_ipxe_uefi_usb.md

Making a UEFI bootable iPXE USB drive

Build the UEFI executable for iPXE

# First we'll clone iPXE
$ git clone git://git.ipxe.org/ipxe.git
# Go into the src directory of the cloned git repo
$ cd ipxe/src
# Compile the UEFI iPXE executable
$ make bin-x86_64-efi/ipxe.efi

Format the USB drive

# First we'll wipe the USB drive (THIS WILL DESTROY ALL DATA)
$ sudo dd if=/dev/zero of=/dev/sdxY bs=512 count=1
# Then we'll partition the drive
$ sudo cfdisk /dev/sdxY
# cfdisk will ask you what type of partition table you want, select GPT

Partitioning the USB drive

1. Make a partition at least 512M in size.
2. Switch the type from Linux Filesystem to EFI system.
3. Write these changes to the USB drive and quit.

Formatting, and mounting the USB drive

# First we'll format it FAT32
$ sudo mkfs.fat -F32 /dev/sdxY
# Now we'll make a directory to mount the USB drive in
$ mkdir /tmp/efidrive
# Now we can mount the USB drive
$ sudo mount /dev/sdxY /tmp/efidrive

Placing the UEFI iPXE executable

# Assuming you're still in the ipxe/src directory
# Make the necessary efi/boot directory in the USB drive
$ sudo mkdir -p /tmp/efidrive/efi/boot
# copy the executable and rename it to bootx64.efi to conform to the UEFI standard
$ sudo cp bin-x86_64-efi/ipxe.efi /tmp/efidrive/efi/boot/bootx64.efi
# unmount the drive
$ sudo umount /tmp/efidrive

You did it!

That's it! You should now have a UEFI-bootable USB drive with the UEFI ipxe binary!

Credit

• arch wiki ESP page
• iPXE download page

Nice gist. Would you know how to create a bootable .iso file instead of making a bootable USB drive?

@jsprickle technically no you cannot replace this with that. One the surface both result in a USB that will boot to iPXE. The document is UEFI bootable USB. What you are providing is a legacy BIOS bootable USB. They are not the same thing.

This is wrong, just try mdir -i bin-x86_64-efi/ipxe.usb 'EFI/BOOT'.

Nice gist. Would you know how to create a bootable .iso file instead of making a bootable USB drive?

I think you want to look into mkisofs. I think you just need to have the same /efi/boot/bootx64.efi file in the iso filesystem, and it should "just work".

Nice gist. Would you know how to create a bootable .iso file instead of making a bootable USB drive?

I think you want to look into mkisofs. I think you just need to have the same /efi/boot/bootx64.efi file in the iso filesystem, and it should "just work".

Or just replace

make bin-x86_64-efi/ipxe.efi

above by

make bin-x86_64-efi/ipxe.iso

Yes, apparently this 5 year old gist has finally been replaced by upstream code in Jan 2021. See src/util/genfsimg.
https://github.com/ipxe/ipxe/blob/master/src/util/genfsimg

They use mcopy for making USB images (with FAT filesystems) and look for one of genisoimage mkisofs xorrisofs, so exactly what we've been doing here.

[edit]
I take it back, there was a src/util/genefidsk that was commited in 2015.
So the only value in this gist are the comments showing how it's done with out compiling from source, requiring only curl and mcopy.

Or just replace

make bin-x86_64-efi/ipxe.efi

above by

make bin-x86_64-efi/ipxe.iso

ah, nice. Didn't realize there was also an .iso target for the efi directory. I will try it when I have a minute. Thanks

the bin-x86_64-efi/ipxe.iso above worked perfectly. Thanks

@jsprickle technically no you cannot replace this with that. One the surface both result in a USB that will boot to iPXE. The document is UEFI bootable USB. What you are providing is a legacy BIOS bootable USB. They are not the same thing.

This is wrong, just try mdir -i bin-x86_64-efi/ipxe.usb 'EFI/BOOT'.

You are partially right. Since it creates quite a messy partition table and not all UEFI can detect such structure (example would be Supermicro servers). While building non-efi bin/ipxe.usb and adding EFI System type partition to this image and copying bin-x86_64-efi/ipxe.efi there - works everywhere.

After a bit of tweaking i made a hybrid - bootable for BIOS and UEFI systems. Recently i got one only with UEFI and no legacy BIOS option.
Idea is to remain with DOS label type (not GPT) for machines with BIOS and create fat32 filesystem type ESP for boot loader which will be accessible and executed by machines only with UEFI firmware.

...
# for systems with BIOS
make bin/ipxe.usb ... # your options may come here

# copy MBR and boot loader image on /dev/sda disk beginning.
dd if=bin/ipxe.usb of=/dev/sda oflag=sync

# for systems with UEFI
make bin-x86_64-efi/ipxe.efi ... # your options may come here

# create ESP partition, FAT32 filesystem and copy boot loader so UEFI firmware can find it
# I left 5Mb offset as MBR and /dev/sda4 partition occupies 4095 sectors from beginning of disk (~2MB)
# partition size - choose any fits your needs. In my case ending point is 311M
parted -s /dev/sda mkpart primary fat32 10MiB 311MiB
parted -s /dev/sda set 1 esp on
partprobe /dev/sda

mkfs.fat -F32 /dev/sda1

mount /dev/sda1 /mnt
mkdir -p /mnt/efi/boot/
cp bin-x86_64-efi/ipxe.efi /mnt/efi/boot/bootx64.efi
umount /mnt

After a bit of tweaking i made a hybrid...

Thanks for sharing. I used your commands to create a USB thumb drive and it works but the drive does not support Ethernet connections made via USB-to-Ethernet adapters. Can this be made to work with such devices? The code listed on this page works with USB-to-Ethernet adapters but it only supports legacy BIOS.

---

UPDATE: So I was successful in creating a USB thumb drive that works with USB-to-Ethernet adapters by adding the USB drivers. Using your commands, I replaced all instances of ipxe.usb with ncm--ecm--axge.usb and replaced ipxe.efi with ncm--ecm--axge.efi.

This works but when PXE booting UEFI, the keyboard stops working. Doesn't do this when PXE booting legacy BIOS. Any ideas?

he is the man, thanks