KernelVM86

Summary

i386/vm86.c

void phantom_v86_run(void *code, int size) - runs given (8086) code, copying it to low (below 1MB) memory first.

Usage example: see in i386/vesa.c

Details

• Runs code by switching to VM86_TSS
• IO access is unrestricted
• Memory access is restriced by check_ua()
• VME is not used. Partially implemented, but not even tried.
• GPF handler is overridden, so no multithreading supposed while running 86 code.

Problems

See phantom_ret_from_vm86() - longjmp is a hack. Normally we must return by jmp to main TSS.

If you going to fix:

To check what's going on first find out which TSS is current when we get to phantom_ret_from_vm86() - I suspect that it is already MAIN_TSS.