Kyösti Mälkki has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/36564 )
Change subject: [TESTONLY]cpu/intel/socket_mPGA604: Run romstage from CAR ......................................................................
Patch Set 2:
27 entries total:
0:1st timestamp 367 11:start of bootblock 894,120 (893,753) 12:end of bootblock 956,393 (62,272) 13:starting to load romstage 1,062,414 (106,020) 14:finished loading romstage 1,080,891 (18,476) 1:start of rom stage 1,110,899 (30,007)
Huh.. it takes 895 ms to reach 11:start of bootblock, and there is only assembly before that. Maybe instruction fetch from FWH is just slow or i82801dx configuration lacks some boost. Note that this is a dual-socket board that does the AP SIPI wakeup thing.
That microcode update in cache_as_ram.S only took 5 ms.