Hi Gordon...

> # ... The CPU has several sleep states, and in
> # the deeper ones, all state / register information is lost, so you
> # have to save it to RAM first, and the BIOS will jump to your wake-up
> # handler to let you restore it when the system wakes up.

> I would be *extremely* surprised if this was ever a hard reset, because
> as noted earlier, there's not a standardized way to perform such a
> reset...

Partially true ;-). ACPI tables tell you how to do all sorts of things
with your system, including "go to suspend"... The wake-up process can
tell a hard reset from suspend-leaving SMI by things like looking at RAM
for some magic (gone at power up reset), looking at ACPI chipset state,
and so on... Not sure about the details. BIOS stuff. Some 15 years ago,
386 BIOSes could distinguish hard reset from "reset to leave protected
mode" (286 software does that) by looking at a flag in CMOS RAM and by
looking at a flag in the keyboard controller (ask it whether the keyboard
controller "send hard reset to system" command is the cause for the reset)
... Basically there are often SEVERAL ways to cause a system reset.

The main question is: Can the IDE controller distinguish hard reset from
"software tells some hardware to trigger a reset" case as good as the BIOS
can? At least c't claims that a suspend / wakeup cycle CAN, at least on
some systems, make the IDE controller issue a reset. Or, if you do not
like that wording, cause a hardware reset signal that gets passed through
the IDE controller to the IDE disk.

> In the BIOS, you can set a password
> because the Freeze command hasn't been issued yet.

Basically true - but are there any BIOSes with any user interface which
can prompt you for the harddisk password yet? If so, which?


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