On Mon, 7 Feb 2000, David Christensen wrote:
In case you're not aware, the SMI is the System Management Interrupt. When an SMI is asserted, the CPU will enter SMM, System Management Mode.
Yes, I've finally begun to realize this.
It is a special mode of the CPU that was originally designed to make it easier for the BIOS to perform power management functions. The SMI is completely transparent to the OS and cannot be masked. The code that is executed in SMM is stored in a special memory area called SMRAM (generally mapped at A0000h-BFFFFh) and cannot be accessed unless operating in SMM (there is usually a lock bit in Intel chipsets that is set and cannot be cleared without resetting the system, this is to protect the SMI handler from being modified). The only way to modify the code in the SMI handler is to write your own BIOS.
openbios to the rescue, I suppose.
geez, this is awful stuff. I'll let you know where I get today.
ron
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