IO(1)IO(1)

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

seg(1), arch(3)

HISTORY

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