Adam Sulmicki adam@cfar.umd.edu writes:
hello, can anyone point me to an documenation on bios's interrupt 15, ah=87. It is 'copy extended memory'.
I suspect the implementation I have is wrong, and thus stops me from adding support for legacy applications under LinuxBIOS.
Going over phoenix manual and Ralf Browns's interrupt list, I know that
CX = counter ES:SI = pointer to GDT
what is not clear to me is what does determine source and destination of the copy. Would it just copy between first and second segment (if so why it is not documented).
I have in my documentation the following addtional information. CX is a count of works (2 byte quantities) With the max being 0x8000
And the format of the GDT is: dummy GDT location source GDT entry target GDT entry BIOS CS BIOS SS
This code works for a 286 so it has a 16MB limit. And segments are limted to 64K, if my memory serves me correctly.
Eric