MirBSD manpage: pchb(4)

PCHB(4)                    BSD Programmer's Manual                     PCHB(4)

NAME

     pchb - PCI-Host Bridge

SYNOPSIS

     pchb* at pci? dev ? function?
     pci* at pchb?

DESCRIPTION

     The pchb driver provides support for PCI-Host adapter-specific functions
     for the following devices:

           i450 PCIset (Orion)
                   Supports additional PCI busses.
           Reliance Computer ROSB4, CNB20HE, CNB20LE
                   Supports additional PCI busses.
           i82424ZX (Saturn)
                   Disables CPU-PCI write posting.
           i82443BX
                   Provides workaround for the following errata: "An incorrect
                   address may be driven on the DRAM bus, resulting in memory
                   data being fetched from the wrong location."
           i82810/810E, i82815/815E, i82820, i82840
                   Supports the random numbers generator, supplying random
                   bytes from the system's thermal noise. Driven by periodic
                   checks for available data from the generator, it supplies
                   entropy to the random(4) driver for common usage.

     On amd64 and i386 systems all other PCI devices of class Bridge and sub-
     class Bridge Host are supported just as PCI attachment points.

     The macppc port supports several Apple and Motorola bridges.

SEE ALSO

     intro(4), pci(4), random(4)

HISTORY

     Random number generator support first appeared in OpenBSD 2.7.

AUTHORS

     Support for true RNG present on i82810 chips was added by Michael
     Shalayeff <mickey@openbsd.org>.

BUGS

     Real RNG probe should fix the PCI scanning loop so it would find the
     Firmware Hub (i82802) which actually contains the RNG device and probe it
     as a real PCI device (i.e., common PCI registers are there).

MirBSD #10-current              April 12, 2000                               1