NAME

	io – access PC I/O registers

SYNOPSIS

	io [ –f file ] [ –WLME ] [ –r | –w ] address [ value ] [ mask ]

DESCRIPTION

io accesses PC I/O space. The operation to be performed is selected with –r or –w for reading or writing, respectively. When a mask is provided for a read, it is applied with a logical AND operation to the value. When a mask is provided for a write, the set bits in the mask select the bits from value to be modified. The default operation size is a byte. C style notation for integers (e.g. 0x42 or 023) is accepted for the address, value and mask parameters. –W    Perform a word (16 bit) operation. –L    Perform a long / double word (32 bit) operation. –M    Access a 64 bit wide machine specific register (MSR). –E    Access embedded controller space. –f    Instead of using /dev/io* as the I/O file depending on the options above, use the argument file instead. This can be used, for example, to access some PCI card config space by specifying /dev/pci/*raw as the I/O file.

SOURCE

	/sys/src/cmd/io.c

SEE ALSO

	seg(1), arch(3)

HISTORY

	Io first appeared in 9front (April, 2011).