setpci is a utility for querying and configuring PCI devices.
All numbers are entered in hexadecimal notation.
Root privileges are necessary for almost all operations, excluding reads of the standard header of the configuration space on some operating systems. Please see lspci(8) for details on access rights.
Before each sequence of operations you need to select which devices you wish that operation to affect.
To query value of a configuration register, just name it (either by typing its name or by typing register address with optional .B, .W or .L suffix specifying register width as byte, word or longword).
To set a register, write reg=values where reg is the same as you would use to query the register and values is a comma-separated list of values you want to write starting with the given address. Each value to be written can be specified either as a hexadecimal number or as a bits:mask pair which causes the bits corresponding to binary ones in the mask to be changed to values of the corresponding bits in the bits
setpci knows the following configuration register names. See PCI bus specifications for their precise meaning or consult header.h or /usr/include/linux/pci.h for a couple of comments.
VENDOR_ID DEVICE_ID COMMAND STATUS REVISION CLASS_PROG CLASS_DEVICE CACHE_LINE_SIZE LATENCY_TIMER HEADER_TYPE BIST BASE_ADDRESS_0 BASE_ADDRESS_1 BASE_ADDRESS_2 BASE_ADDRESS_3 BASE_ADDRESS_4 BASE_ADDRESS_5 CARDBUS_CIS SUBSYSTEM_VENDOR_ID SUBSYSTEM_ID ROM_ADDRESS INTERRUPT_LINE INTERRUPT_PIN MIN_GNT MAX_LAT PRIMARY_BUS SECONDARY_BUS SUBORDINATE_BUS SEC_LATENCY_TIMER IO_BASE IO_LIMIT SEC_STATUS MEMORY_BASE MEMORY_LIMIT PREF_MEMORY_BASE PREF_MEMORY_LIMIT PREF_BASE_UPPER32 PREF_LIMIT_UPPER32 IO_BASE_UPPER16 IO_LIMIT_UPPER16 BRIDGE_ROM_ADDRESS BRIDGE_CONTROL CB_CARDBUS_BASE CB_CAPABILITIES CB_SEC_STATUS CB_BUS_NUMBER CB_CARDBUS_NUMBER CB_SUBORDINATE_BUS CB_CARDBUS_LATENCY CB_MEMORY_BASE_0 CB_MEMORY_LIMIT_0 CB_MEMORY_BASE_1 CB_MEMORY_LIMIT_1 CB_IO_BASE_0 CB_IO_BASE_0_HI CB_IO_LIMIT_0 CB_IO_LIMIT_0_HI CB_IO_BASE_1 CB_IO_BASE_1_HI CB_IO_LIMIT_1 CB_IO_LIMIT_1_HI CB_SUBSYSTEM_VENDOR_ID CB_SUBSYSTEM_ID CB_LEGACY_MODE_BASE
`setpci -d *:* latency_timer=40' sets the latency timer to 64 (40 hexadecimal).
`setpci -s 0 device_id vendor_id' lists ID's of devices in slot 0 in all buses.
`setpci -s 12:3.4 3c.l=1,2,3' writes longword 1 to register 3c, 2 to register 3d and 3 to register 3e of device at bus 12, slot 3, function 4.
`setpci -s 13:8.4 40.b=50:d0,04:0c,ff' works on bus 13, device 8, function 4: turns bit 7 off and bits 6 and 4 on in the byte register 40; turns bit 3 off and bit 2 on in the byte register 41; sets byte register 42 to ff.