In the rfc4578 there are following type requested:

Type   Architecture Name
----   -----------------
  0    Intel x86PC
  1    NEC/PC98
  2    EFI Itanium
  3    DEC Alpha
  4    Arc x86
  5    Intel Lean Client
  6    EFI IA32
  7    EFI BC
  8    EFI Xscale
  9    EFI x86-64

use-host-decl-names on;
ddns-update-style interim;
ignore client-updates;
next-server 192.168.1.1;
authoritative;
 
subnet 192.168.1.0 netmask 255.255.255.0 {
    option subnet-mask 255.255.255.0;
    range dynamic-bootp 192.168.1.10 192.168.1.254;
    default-lease-time 21600;
    max-lease-time 43200;
    option domain-name-servers 192.168.1.1;
    #option routers x.x.x.x;
 
    class "UEFI-32-1" {
    match if substring(option vendor-class-identifier, 0, 20) = "PXEClient:Arch:00006";
    filename "i386-efi/ipxe.efi";
    }
 
    class "UEFI-32-2" {
    match if substring(option vendor-class-identifier, 0, 20) = "PXEClient:Arch:00002";
     filename "i386-efi/ipxe.efi";
    }
 
    class "UEFI-64-1" {
    match if substring(option vendor-class-identifier, 0, 20) = "PXEClient:Arch:00007";
     filename "ipxe.efi";
    }
 
    class "UEFI-64-2" {
    match if substring(option vendor-class-identifier, 0, 20) = "PXEClient:Arch:00008";
    filename "ipxe.efi";
    }
 
    class "UEFI-64-3" {
    match if substring(option vendor-class-identifier, 0, 20) = "PXEClient:Arch:00009";
     filename "ipxe.efi";
    }
 
    class "Legacy" {
    match if substring(option vendor-class-identifier, 0, 20) = "PXEClient:Arch:00000";
    filename "undionly.kkpxe";
    }
 
}

• https://www.syslinux.org/archives/2014-October/022683.html
• https://wiki.fogproject.org/wiki/index.php/BIOS_and_UEFI_Co-Existence