[LinuxBIOS] RE: E7501 raminit changes

[Steven J. Magnani]

> Does anyone know if de-asserting A20M# is enough to cause A20 to behave
> normally? On our board, after we force A20M# high, the system continues

to
> behave as if A20 is always zero. We're using an embedded board, so

there is no
> keyboard controller in the mix - I/O port 0x92 is enough to toggle

A20M#.

A note for the record. It appears to be a feature of the Xeon that a
change in A20M# doesn't take effect until after the processor steps
forward at least one instruction. So if you use an emulator to stop the
processor and toggle A20M#, you won't see any change in memory behavior
until you step through the next instruction.

Doh!

Steve