— NEC PC-9801 extension board
pcex0 at cbus0
The file /dev/pcexmem is an mmap(2) capable interface to the memory area of the installed board at "NEC PC-9801 extension board slot" on LUNA-88K2. Byte offsets in this file are interpreted as relative memory addresses of the installed board. The range should be between 0x0 and 0xffffff.
The I/O port area of the installed board is accessed via the file /dev/pcexio in the same manner as /dev/pcexmem. The range should be between 0x0 and 0xffff.
The following ioctl(2) calls apply to /dev/pcexmem and /dev/pcexio in order to handle interrupts of this extension slot. Currently 7 levels of interrupt (0 to 6) are supported.
- Register the specified interrupt level with this driver to handle.
- Unregister the specified interrupt level with this driver.
- Wait for the interrupt with the specified level.
- PCEXWAITINT timeouts (currently 1 second).
The /dev/pcexmem and /dev/pcexio files first appeared in OpenBSD 5.6.