.\" $NetBSD: pcibios.4,v 1.8 2000/08/10 21:19:42 soda Exp $ .\" .\" Copyright (c) 1999, 2000 The NetBSD Foundation, Inc. .\" All rights reserved. .\" .\" This code is derived from software contributed to The NetBSD Foundation .\" by Lennart Augustsson. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the NetBSD .\" Foundation, Inc. and its contributors. .\" 4. Neither the name of The NetBSD Foundation nor the names of its .\" contributors may be used to endorse or promote products derived .\" from this software without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS .\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED .\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS .\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" .Dd July 22, 2000 .Dt PCIBIOS 4 .Os .Sh NAME .Nm pcibios .Nd introduction to PCI BIOS support .Sh SYNOPSIS .Cd "options PCIBIOS" .Cd "options PCIBIOSVERBOSE" .Cd "options PCIBIOS_ADDR_FIXUP" .Cd "options PCIBIOS_BUS_FIXUP" .Cd "options PCIBIOS_INTR_FIXUP" .Cd "#options PCIBIOS_IRQS_HINT=0x0a00 #IRQ 9,11" .Cd "#options PCIBIOS_INTR_FIXUP_FORCE" .Cd "options PCIBIOS_INTR_GUESS" .Cd "#options PCIINTR_DEBUG" .Pp .Sh INTRODUCTION .Nx provides support for setting up PCI controllers, bridges, and devices using information extracted from the BIOS. .Pp Ideally, the boot firmware of a machine (a.k.a. BIOS) should set up all PCI devices; assigning them I/O and memory addresses and interrupts. Alas, this does not always happen, so there is some PC specific code that can do the initialization when .Nx boots. .Pp Options: .Bl -tag -width PCIBIOS_INTR_FIXUP -offset 3n .It Nm PCIBIOS turn on the PCI BIOS support. .It Nm PCIBIOSVERBOSE make the setup procedure verbose. .It Nm PCIBIOS_ADDR_FIXUP fixup PCI I/O and memory addresses. .Pp Some BIOS implementations don't allocate I/O space and memory space for some PCI devices. Especially, a BIOS which is .Qq PnP OS mode enabled shows this behavior. Since necessary space isn't allocated, those devices will not work without special handling. This option allocates I/O space and memory space instead of relying upon the BIOS to do so. If necessary space is already correctly assigned to the devices, this option leaves the space as is. Although many BIOS implementations leave CardBus bridges' space unallocated, the CardBus bridge device driver doesn't require this option, since the driver allocates necessary space by itself. .It Nm PCIBIOS_BUS_FIXUP fixup PCI bus numbering; needed for many .Xr cardbus 4 bridges. .Pp Each PCI bus and CardBus should have a unique bus number. But some BIOS implementations don't assign a bus number for subordinate PCI buses. And many BIOS implementations don't assign a bus number for CardBuses. A typical symptom of this is the following boot message: .D1 Sy cardbus0 at cardslot0: bus 0 device 0... Please note that this cardbus0 has a bus number .Sq 0 , but normally the bus number 0 is used by the machine's primary PCI bus. Thus, this bus number for cardbus is incorrect .Pq not assigned . In this situation, a device located in cardbus0 doesn't show correct device ID, because its bus number 0 incorrectly refers to the primary PCI bus, and a device ID in the primary PCI bus is shown in the boot message instead of the device's ID in the cardbus0. This option assigns bus numbers for all subordinate PCI buses and CardBuses. Since this option renumbers all PCI buses and CardBuses, all bus numbers of subordinate buses become different when this option is enabled. .It Nm PCIBIOS_INTR_FIXUP fixup PCI interrupt routing. .Pp Some BIOS implementations don't assign an interrupt for some devices. This option assigns an interrupt for such devices instead of relying upon the BIOS to do so. If the BIOS has already assigned an interrupt to a device, this option leaves the interrupt as is. .It Nm PCIBIOS_IRQS_HINT hint for IRQ use. When the .Em PCIBIOS_INTR_FIXUP cannot guess an adequate IRQ for a device, the hint is used. .Pp The value is a logical or of power-of-2s of allowable interrupts: .Bl -column "XX-0xffff" "XX-0xffff" "XX-0xffff" "XX-0xffff" -compact -offset 2n .It Em "IRQ Value" Em "\tIRQ Value" Em "\tIRQ Value" Em "\tIRQ Value" .It "\& 0 0x0001" "\t 4 0x0010" "\t 8 0x0100" "\t12 0x1000" .It "\& 1 0x0002" "\t 5 0x0020" "\t 9 0x0200" "\t13 0x2000" .It "\& 2 0x0004" "\t 6 0x0040" "\t10 0x0400" "\t14 0x4000" .It "\& 3 0x0008" "\t 7 0x0080" "\t11 0x0800" "\t15 0x8000" .El For example, .Qq Sy options PCIBIOS_IRQS_HINT=0x0a00 allows IRQ 9 and IRQ 11. The kernel global variable .Va pcibios_irqs_hint holds this value, so a user can override this value without kernel recompilation. For example: .Bl -bullet -compact .It To specify this value on the fly, type the following command at the boot prompt to drop into DDB (the in-kernel debugger; you have to specify .Qq Sy options DDB to make kernel with DDB): .Dl Ic boot -d And type the following command on .Qq Sy db> prompt: .Dl Ic write pcibios_irqs_hint 0x0a00 Then type the following to continue to boot: .Dl Ic c .It To modify kernel image without kernel recompilation, run the following command on shell: .Dl Ic gdb --write /netbsd And type the following commands at the .Qq Sy (gdb) prompt: .Dl Ic set pcibios_irqs_hint=0xa00 .Dl Ic quit .El .It Nm PCIBIOS_INTR_FIXUP_FORCE .Pp Some buggy BIOS implementations provide inconsistent information between the PCI Interrupt Configuration Register and the PCI Interrupt Routing table. In such case, the PCI Interrupt Configuration Register takes precedence by default. If this happens, a kernel with .Em PCIBIOSVERBOSE shows .Qq Sy WARNING: preserving irq XX in the PCI routing table. If .Em PCIBIOS_INTR_FIXUP_FORCE is specified in addition to the .Em PCIBIOS_INTR_FIXUP , the PCI Interrupt Routing table takes precedence. In this case, a kernel with .Em PCIBIOSVERBOSE shows .Qq Sy WARNING: overriding irq XX in the PCI routing table. The necessity of this option is doubtful, and we may remove this option in the future. If you find that this option is worth preserving, please report it with send-pr. .It Nm PCIBIOS_INTR_GUESS make .Em PCIBIOS_INTR_FIXUP work with unknown interrupt router. .Pp If a PCI interrupt router is not known, normally interrupt configuraion will not be touched. But if .Em PCIBIOS_INTR_GUESS is specified in addition to the .Em PCIBIOS_INTR_FIXUP , and if a PCI interrupt routing table entry indicates that only one IRQ is available for the entry, the IRQ is assumed to be already connected to the device, and corresponding PCI Interrupt Configuration Register will be configured accordingly. .It Nm PCIINTR_DEBUG make the .Em PCIBIOS_INTR_FIXUP procedure verbose. .El .Sh SEE ALSO .Xr cardbus 4 , .Xr pci 4 .Sh HISTORY The .Nm code appeared in .Nx 1.5 . .Sh BUGS The .Em PCIBIOS_ADDR_FIXUP option may conflict with the PCI CardBus driver's own address fixup.