gio(4) - NetBSD Manual Pages

GIO(4)              NetBSD/sgimips Kernel Interfaces Manual             GIO(4)


NAME

     gio -- SGI's Graphics I/O (GIO) bus (an early PCI-like bus)


SYNOPSIS

     gio0 at imc0
     gio0 at pic0


DESCRIPTION

     The gio bus is a bus for connecting high-speed peripherals to the main
     memory and CPU.  The devices themselves are typically (but not necessar-
     ily) connected to the sgimips/hpc(4) peripheral controller, and memory
     and CPU are accessed through the sgimips/imc(4) (Indy Memory Controller)
     or sgimips/pic(4) (Processor Interface Controller).  The gio bus is found
     on the Personal Iris 4D/3x, Indigo, Indy, Challenge S, Challenge M, and
     Indigo2 machines and exists in three incarnations: GIO32, GIO32-bis, and
     GIO64.


SEE ALSO

     sgimips/giopci(4), sgimips/grtwo(4), sgimips/hpc(4), sgimips/imc(4),
     sgimips/light(4), sgimips/newport(4), sgimips/pic(4)


HISTORY

     The gio driver first appeared in NetBSD 1.5.


CAVEATS

     Challenge S systems may use only one gio DMA-capable expansion card,
     despite having two slots.  Cards based on the sgimips/hpc(4) controller,
     such as the GIO32 scsi and E++ Ethernet adapters, must be placed in slot
     1 (closest to the side of the case).  All other cards must be placed in
     slot 0 (adjacent to the memory banks).

     Indigo2 and Challenge M systems contain either three or four GIO64 con-
     nectors, depending on the model.  However, in both cases only two elec-
     trically distinct slots are present.  Therefore, distinct expansion cards
     may not share physical connectors associated with the same slot.  Refer
     to the PCB stencils to determine the association between physical connec-
     tors and slots.


BUGS

     Systems employing the sgimips/imc(4) may experience spurious SysAD bus
     parity errors when using expansion cards, which do not drive all data
     lines during a CPU PIO read.  The only workaround is to disable SysAD
     parity checking when using such cards.

NetBSD 10.99                   February 17, 2017                  NetBSD 10.99