PCKBC(4) | Device Drivers Manual | PCKBC(4)

# NAME

`pckbc` — PC (ISA) keyboard controller driver

# SYNOPSIS

`pckbc* at isa? flags 0x00` (alpha, amd64, i386, loongson)
`pckbc* at acpi? flags 0x00` (amd64)
`pckbc* at ebus?` (sparc64)
`pckbd* at pckbc?`
`pms* at pckbc?`

# DESCRIPTION

The `pckbc` driver handles resource allocation and device attachment for the traditional PC/AT keyboard controller, or emulations thereof. It provides up to two logical connections for child devices, the “keyboard” slot for a keyboard and the “auxiliary” slot for mice (the latter might be missing in older keyboard controllers, or recent emulations).

To avoid attaching a phantom PS/2 keyboard device, the isa(4) attachment of the `pckbc` driver will attempt to detect USB legacy keyboard emulation on amd64 and i386 systems. Unfortunately, the detection heuristics may fail on older systems with a real PS/2 keyboard. The keyboard can be forced to attach on these systems, by changing the device flags to 1.

The acpi(4) attachment of the `pckbc` driver defaults to attach only where it would perform better than its legacy isa(4) attachment. Should this logic be insufficient, it is possible to force it to always attach, by changing its device flags to 1.

# SEE ALSO

acpi(4), ebus(4), intro(4), isa(4), pckbd(4), pms(4), boot_config(8)

February 10, 2025 | Debian