For the printing and parsing functionalit, we use the Tianocore routines directly.

efivar-dp-format.c is a copy of MdePkg/Library/UefiDevicePathLib/DevicePathToText.c
efivar-dp-parse.c is a copy of MdePkg/Library/UefiDevicePathLib/DevicePathFromText.c

These files are first mechnaically processed with

sed -e "s/L'/'/;"'s/L"/"/g;s/%g/%36s/g;s/%a/%s/g;s/^VOID/static VOID/g;s/ *$//g'

for several reasons. We're moving from wide rotuines to narrow
routines. The UTC-2 this code is written for is a bad match for
wchar_t which is an int. It's a much better match for plain narrow
characters on FreeBSD. So we pretend that CHAR16 for these files is
really char * (ASCII).

Next, we have have to convert the Unicode printf that this code
expects to FreeBSD's printf. %g means "Print the GUID" and %a means
"print the ASCII string." so we mechanically convert them. Once we've
done that we can compare efivar-dp-*.c to its source to see what's
changed. Because we go through this indirection, I've done that
outside of svn. To upgrade you have to do these files by hand. You
have to go through and make routines static.

uefi-*.[ch] are internal routines to support this. They've been copied
from EDK2 as well, but in a more hap-hazard manner. This was a trade
off between ease of implementation / upgrade vs pulling in too much
since less than half of any file was needed.

efi-osdep.h shims the EDK2 types to FreeBSD's types. It's included by
ProcessorBind.h which EDK2 uses to define the CPU. We keep it separate
from uefi-dplib.h to allow better sharing.

uefi-dplib.h shims the EDK2 routines that are needed to FreeBSD's
routines. This is relatively easy since we map all the UCS-2 routines
to simple char * routines.

RESIST THE URGE TO CLEAN UP THESE FILES.