Skip CAR setup in FSP?

[Mason M]

Hi coreboot people,

I noticed the option in soc/intel/skylake/Kconfig called SKIP_FSP_CAR,
which based on the description, it sounds like the intention is to simply
skip the TempRamInit portion of FSP.  However, from looking at the code in
cache_as_ram.inc, the jump to TempRamInit is still performed, but with an
additional #include of a non-existent file called "soc/car_setup.S"
beforehand.  A little more confusingly, only if the option is set does the
code bother to assign the UPD values FspCarBase and FspCarSize a meaningful
value in skylake/romstage/romstage.c.  Compounding on top of this, the
option is enabled by default, seeming to imply it's the preferred way to go
for Skylake FSP builds.

Can anyone explain to me what the purpose of this option is?  Is it simply
old code that was accidentally left behind?

Much appreciated,
Mason