I have a motherboard with an integrated COM port. This port works in UEFI Shell after loading the drivers:
load TerminalDxe.efi PciSioSerialDxe.efi

Drivers unpacked from edk2.git-ovmf-x64-0-20211216.122.gc9b7c6e0cc.noarch.rpm\.\usr\share\edk2.git\ovmf-x64\OVMF-pure-efi.fd

I have a second PC connected with a null-modem cable and after loading the drivers UEFI Shell automatically appears in Putty.

I have another motherboard that does not have an integrated RS232 port. I connected PCIe card with serial port (SER5427A) but after loading the drivers .efi port does not work.
How to enable port on this card under UEFI Shell?