Welcome to the dark corner of BIOS reverse engineering, code injection and various modification techniques only deemed by those immensely curious about BIOS

Friday, March 22, 2013

DOS Protected Mode Interface (DPMI)

DPMI is outdated by today's standard of course. However, in certain situation it comes handy. I've been looking for documents/standards/specifications from my early days of BIOS reversing that could explain most of the 32-bit code I'd seen on the BIOS.

One of the most intriguing terms were the memory related terms, e.g. high memory, upper memory, etc. I came to think that there were no standard(s) at all which govern the use of the term. However, upon reading the DPMI specification, I finally realize that the "gaps" (in my knowledge) between the 16-bit code and 32-bit code on the BIOS are covered by the DPMI specification. Well, not all of them of course because there are still the voodoo mode. But, nonetheless, a large fraction of the missing link is in the DPMI.

For those interested on the spec. This is the link: http://homer.rice.edu/~sandmann/cwsdpmi/dpmispec1.pdf.

Have a nice weekend :-)
Post a Comment


Anonymous said...

don't forget VCPI that predates DPMI https://student.brighton.ac.uk/burks/pcinfo/progdocs/vcpi.htm

Darmawan Salihun said...

Thanks for that. I've never knew about VCPI before.