Sucess vm86 call -- Dosemu

Eric W. Biederman (ebiederm@cse.unl.edu)
16 Oct 1996 23:49:43 -0500


This is just a FYI note to let everyone who has been wondering about
this issue know I have managed to create a patch that seems to fix the
broken vm86 behavior in 2.1.[0-4]. The trouble was created primarily
becase vm86_regs was a superset of pt_regs, but pt_regs changed!

Dosemu for me survives 500+ calls to vm86() but it still dies before
it comes up properly :( It seems to die because it receives a General
Protection Fault, for some reason besides a protected instruction
executing. I don't _think_ jo $+0 is protected. It also seems to
exercise some subtle bugs. (Either in dosemu the kernel or both).

Does anyone know what error codes a GPF can produce and what they
mean?

Eric