PCI "SET EXT_REGISTER"

Change the content of a register in an extended PCI configuration area.

Syntax

PCI "SET REGISTER[/BASE=base_address] /BUS=bus_id/DEV=device_id/FUNC=func_id/OFFSET=offset/VAL=value/LENGTH=length"

Parameters

/BASE

Specifies the register's base address; base_address is a hexadecimal number. If omitted, the debugger scans for an MCFG table and uses the memory-mapped base address from it.

/BUS=bus_id

Specifies the PCI bus; bus_id is a decimal number.

/DEV=dev_id

Specifies the PCI device; device_id is a decimal number.

/FUNC=func_id

Specifies the PCI function; function_id is a decimal number.

/OFFSET=offset

Specifies the start address of the registers to be displayed; offset is a hexadecimal number from 0x0 to 0xFFF.

/VAL=value

Specifies the new value to be written to the register; value is a hexadecimal number.

/LENGTH=length

Specifies whether the value to be written is a 1-, 2- or 4-bytes value.

Description

This command changes the content of a register of an extended PCI configuration area as defined by /BUS, /DEV, /FUNC, and /OFFSET. It writes a new value to the register as defined by /VAL and /LENGTH. To access the extended PCI configuration area, a base address is required. To enter a base address manually, use the /BASE option. If this option is omitted, the debugger scans for a valid SFI or RSDP to locate a MCFG table and then uses the memory-mapped base address from this table.

Note

Make sure to use this command only after full initialization of the platform's PCI subsystem. Accessing the PCI bus before that point in time might lead to target instabilities up to and including crashes.

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