coreboot

Boards containing dual LGA771 Xeon CPU's with intel 5000P northbridge and 3100 southbridge chipsets have been supported with coreboot in the past but were dropped before "EARLY_CBMEM_INIT" and "RESOURCE_ALLOCATOR_V4" were introduced see:

Supermicro X7DB8
https://review.coreboot.org/c/coreboot/+/493

ASUS DSBF
https://review.coreboot.org/c/coreboot/+/1223

Fujitsu TX200-S3(unmerged)
https://review.coreboot.org/c/coreboot/+/1202

Removal of these boards was done when "LATE_CBMEM_INIT" became unsupported:
https://review.coreboot.org/c/coreboot/+/22030
https://review.coreboot.org/c/coreboot/+/22031

VIA CX700:
Likewise the VIA CX700 support was also removed in past because of "LATE_CBMEM_INIT" but was restored years later, however that chip is probably a lot less complex than the dual socket intel series:
https://review.coreboot.org/c/coreboot/+/26678
https://review.coreboot.org/c/coreboot/+/82770

Currently coreboot supports a even older dual socket MPGA604 Xeon server board and multiple single socket LGA775 desktop boards. The later should already unofficially support a single modded LGA771 Xeon CPU (drilled holes, stickermod and microcode) by current coreboot codebase:

#CPU_INTEL_SOCKET_MPGA604
aopen/dxplplusu

#select CPU_INTEL_SOCKET_LGA775
asus/p5qc
asus/p5gc-mx
asus/p5qpl-am
asus/p5ql-em
foxconn/g41s-k
acer/g43t-am3
asrock/g41c-gs
gigabyte/ga-945gcm-s2l
gigabyte/ga-g41m-es2l
intel/dg43gt
intel/dg41wv
lenovo/thinkcentre_a58

Why Research 5000P?
Although these LGA771 server boards may "not" seem interesting for any current server or workstation use and are mostly unobtainable, some of them ship with regular ATX / FAN power connectors and socket-ed PLCC-32 ROM's mostly Asus, Gigabyte and Supermicro. These may still assist in debugging coreboot support for other boards with similar chipsets that lack socket-ed ROM's.

See the retroweb summary of some socket 5000P boards:
https://theretroweb.com/motherboards?itemsPerPage=24&chipsetIds%5B%5D=1221

See the retroweb summary of some socket 5000V boards:
https://theretroweb.com/motherboards?itemsPerPage=24&chipsetIds%5B%5D=1223

See the retroweb summary of some socket 5000X boards, see Dell Precision 490(soldered PLCC32) and SuperMicro DB7A* boards with similar MEM/CPU layout:
https://theretroweb.com/motherboards?itemsPerPage=24&chipIds%5B0%5D=317

Why research 5000X (Greencreek)?
Possible interesting workstations that can easily accommodate 6+ HDD's, push full 10Gbe without a problem and still work silent (including FAN control) are easily available from Apple. However with the downside of these boards being "EFI32" and soldered 40pin TSOP "M50FW016" 2MB FWH ROM's which makes coreboot development a PITA... They all share dual LGA771 CPU sockets (quadcore on mp11 needs mp21 firmware) and have 8 FB-DIMMS with 4x DIMM on 2 risers, with different PCIe configs:

Apple MacPro 1,1 (4x PCIe x16 slots @2.5GT/s with 3x PCIe x8 lanes and 1x PCIe x1 lane option)
Apple MacPro 2,1 (4x PCIe x16 slots @2.5GT/s with 3x PCIe x8 lanes and 1x PCIe x1 lane option)
Apple MacPro 3,1 (4x PCIe x16 slots wtih 2x x16 lanes @5GT/s and 2x PCIe x4 lanes @2.5GT/s locked)
(mp3,1 has 5400 northbridge instead which has +Harpertown CPU upgrade support)

One step closer to coreboot support for these MacPro's is flashrom support was lacking for writing the full ROM on these early MacPro's. However with a special Mac OSX bless command and power-on procedure writing the full ROM from linux with flashrom is now verified both on mp21 and mp31 (more details in flashrom ticket). But this is just a very tiny step from coreboot support...

How much effort will re-supporting these intel 5000p and possibly 5000x northbridge series with current coreboot codebase be?