parted /dev/sda -- mklabel gpt
parted /dev/sda -- mkpart biosboot 1MiB 3MiB
parted /dev/sda -- set 1 bios_grub on
parted /dev/sda -- mkpart ESP fat32 3MiB 1027MiB
parted /dev/sda -- set 2 esp on
parted /dev/sda -- mkpart ISO ext4 1027MiB 13000MiB
parted /dev/sda -- mkpart DATA fat32 13000MiB 100%

parted /dev/sda print

mkfs.vfat -F32 /dev/sda2
mkfs.ext4 /dev/sda3
mkfs.vfat -F32 /dev/sda4

mount /dev/sda2 /mnt/usb
mkdir -p /mnt/usb/boot/grub
grub-install --target=x86_64-efi --efi-directory=/mnt/usb --boot-directory=/mnt/usb/boot --removable
grub-install --target=i386-pc --boot-directory=/mnt/usb/boot /dev/sda

mkdir /mnt/usb/EFI/tools/
mkdir -p /mnt/iso
mount /dev/sda3 /mnt/iso

/mnt/iso/archlinux-x86_64.iso
/mnt/iso/debian-13-amd64-netinst.iso
/mnt/iso/systemrescue-amd64.iso
/mnt/usb/EFI/tools/memtest.efi

/mnt/usb/boot/grub/grub.cfg

menuentry "System Rescue CD" {
    search --no-floppy --label ISO --set=root
    set iso="/systemrescue-amd64.iso"
    loopback loop ($root)$iso
    linux (loop)/sysresccd/boot/x86_64/vmlinuz archisobasedir=sysresccd archisolabel=ISOUSB img_dev=/dev/disk/by-label/ISOUSB img_loop=$iso
    initrd (loop)/sysresccd/boot/x86_64/sysresccd.img
}
menuentry "Arch Linux" {
    search --no-floppy --label ISO --set=root
    set iso="/archlinux-x86_64.iso"
    loopback loop ($root)$iso
    linux (loop)/arch/boot/x86_64/vmlinuz-linux archisobasedir=arch archisolabel=ISOUSB img_dev=/dev/disk/by-label/ISOUSB img_loop=$iso
    initrd (loop)/arch/boot/x86_64/initramfs-linux.img
}
menuentry "Debian 13" {
    search --no-floppy --label ISO --set=root
    set iso="/debian-13-amd64-netinst.iso"
    loopback loop ($root)$iso
    linux (loop)/install.amd/vmlinuz boot=install iso-scan/filename=$iso quiet
    initrd (loop)/install.amd/initrd.gz
}
menuentry "Memtest" {
    insmod chain
    search --no-floppy --file /EFI/tools/memtest.efi --set=root
    chainloader /EFI/tools/memtest.efi
}