D510MO motherboard with newest BIOS (updated to MOPNV10J.86A.0154) booting Gentoo Linux.
Here are the last 6 lines of output:
[ 0.003333] x86 PAT enabled: cpu 2, old 0x70406000070406, new 0x70106000070106
[ 0.248318] CPU2: Intel(R) Atom(TM) CPU D510 @ 1.66GHz stepping 0a
[ 0.249121] checking TSC synchronization [CPU#0 -> CPU#2]:]
[ 0.249999] Measured 40 cycles TSC warp between CPUs, turning off TSC clock
[ 0.249999] Marking TSC unstable due to check_tsc_sync_source failed
[ 0.250117] Booting processor 3 APIC 0x3 ip 0x6000
// hangs here
It happens from time to time, ~once per 5 successful boots. You find it's common if you google it.
Have you resolved this problem? I'm using a COM Express module with ATOM N450, have the same problem with you. It seems that the bootstrap CPU can not kick off the application cpu. The bootstrap CPU sent IPI to kick off the AP, but the trampoline code of the AP be executed. This doens't happen every time. But if it stuck at "Booting processor.....", press a key on the keyboard will make it continue, and everyting seems OK then.