I have one and only one application (coded in Visual C++) running on a Windows XP Embedded system. That application needs to read several bytes of data from the BIOS ROM. Can someone please suggest a method for doing this?

The data to be read will have been previously stored in the BIOS ROM at a known address when the chip was burned. I know that the BIOS is mapped to the upper 512K of the 4G address space (0xfff80000-0xffffffff) so it seems reasonable to read it directly from there using inline assembly code, but this naturally results in a C0000005 access violation.

However, there must be a way to access that memory because I have found two independent programs (RW-Everything and HWDIRECT) which can dump memory from anywhere within the 4G address space, including the BIOS. If I could locate the relevant source code for one of these programs, that would certainly help to resolve the problem.

An alternative approach might be to use a software interrupt to access a BIOS service routine to return the data I need, if such exists.

Any suggestions or ideas would be greatly appreciated.

Thanks,
Bob.