4 ms·
I don't think SMM requires UEFI, either, actually... I believe there have been BIOSes that initialized SMM also.
by hackmiester 5y ago
I don't think SMM requires UEFI, either, actually... I believe there have been BIOSes that initialized SMM also.
- p_l 5y agoIndeed. SMM exists because it was unfeasible to require the OS to provide necessary power management features at a time when running DOS and unmodified Win2.x and Win3.x were crucial features. Thus 386SL was born, with SMM mode so that the firmware could hijack DOS without being stopped by accidental modification of interrupt table. A bunch of stuff was later loaded into SMM for various reasons, both more and less benign. Turion X2 CPUs used SMM resident handler to synchronise cpus when going into deeper sleep levels (iirc C3 required the SMM handler, C1 and C2 were doable without, but C1E required it as well)
- deleted 5y ago[deleted]