In order for the EC to maintain the state of whether or not to set the
flash descriptor override across a power cycle, the AC adapter must be
connected, as the system leaves the voltage rail that the EC uses
powered under this condition. Without this, the utility may fail,
continually asking the user to power off and on.
On Linux, CONFIG_X86_IOPL_IOPERM must be set for the kernel, or else the
iopl call will error with "Function not implemented". Make a note of
this in case a user runs into this issue.
Signed-off-by: Nicholas Chin <nic.c3.14@gmail.com>
These systems have a report that the unlock utility does not work.
Until there are multiple reports of failed unlocks and a technical
determination of why it doesn't work, they will not be listed as
explicitly unsupported.
As this utility requires access to /dev/mem, the default protections of
Linux and OpenBSD must be relaxed to allow this. Make a note of this in
the instructions.
The old Open Security Training site had a course called Advanced x86:
BIOS and SMM Internals, which had a set of slides outlining the method
to supress SMIs by changing the GBL_SMI_EN bit. Add a reference to it as
this is where I originally learned of this method.
linear cannon