[EMAIL PROTECTED] wrote:
Hi,Read the docs for the go32 unit (in doc\units.pdf) or some protected mode / DPMI tutorial.
under GO32V2 i want to call BIOS PnP function with entry point
db $FF,$1E; dw PnP_EntryPoint or call DWord ptr [PnP_EntryPoint]
but always i got error "SIGSEGV - segmentation violation". PnP_EntryPoint (type pointer) is normally somewhere in BIOS area at F000:xxxxh.
But i don't know how can i do that -> "make a readable and writable data segment descriptor".
And the second problem is how can i make a pointer "PnP_EntryPoint" to this real memory area.
Under real DOS with BP7 it is O.K.
You can create descriptors with the allocate_ldt_descriptors function. Then you can use other functions to set the access rights and limit of the descriptor, etc...
In BP7 it works, because you're in real mode. In FPC/go32v2 you're in protected mode so you can't call directly code that was designed to run in real mode. You should use the DPMI services. Some newer BIOS functions can be called directly from protected mode (as well as real mode), but they require that you set up some special code and data segment descriptors. (the VBE3 functions support that, I guess the PnP functions are the same, although I never used them) All this can be done using DPMI (the go32 unit) but you should know how protected mode works. :)
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