GIO(4) | Device Drivers Manual (sgimips) | GIO(4) |
gio
— SGI's
Graphics I/O (GIO) bus (an early PCI-like bus)
gio0 at imc0
gio0 at pic0
The gio
bus is a bus for connecting
high-speed peripherals to the main memory and CPU. The devices themselves
are typically (but not necessarily) 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.
sgimips/giopci(4), sgimips/grtwo(4), sgimips/hpc(4), sgimips/imc(4), sgimips/light(4), sgimips/newport(4), sgimips/pic(4)
The gio
driver first appeared in
NetBSD 1.5.
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 connectors, depending on the model. However, in both cases only two electrically 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 connectors and slots.
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.
February 17, 2017 | NetBSD 10.99 |