SVR5 and SCO OpenServer

mca(D5)

mca -- data format of the MCA device configuration space

Synopsis

   #include <sys/eisa.h>
   #include <sys/ddi.h>

Description

MCA device configuration space is persistent memory provided by the hardware/firmware associated with an MCA bus that is used to store parameters of the devices attached to the bus.

Device configuration space for MCA devices is simply an array of uchar_t bytes, one for each of the eight POS (Programmable Option Select) registers.

Usage

DDI access to MCA configuration information

ODDI access to MCA configuration information

SCO OpenServer drivers can access MicroChannel device configuration information. The Programmable Option Select (POS) registers on a MicroChannel machine can be read but should not be written by device drivers. In particular, MicroChannel drivers should never change any adapter settings that are configurable through the standard MicroChannel device configuration process involving reference floppies and option disks.

Hardware applicability

x86/Pentium compatible architectures

Version pplicability

ddi: 1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp

oddi: 1, 2, 2mp, 3, 3mp, 4, 4mp, 5, 5mp

SCO OpenServer and SVR5 compatibility

The configuration space layout is determined by industry standards boards; drivers written for SVR5 and SCO OpenServer access the same configuration space, although they use different methods for that access.

References

cm_read_devconfig(D3), cm_write_devconfig(D3), cm_params(D5)

``MicroChannel configuration information'' in HDK Technical Reference