.SH SYNOPSIS
.B io
[
-.B -WLMrw
+.B -WLMErw
]
.I address
[
.TP
.B -M
Access a 64 bit wide machine specific register (MSR).
+.TP
+.B -E
+Access embedded controller space.
.SH SOURCE
.B /sys/src/cmd/io.c
.SH SEE ALSO
-.IR seg (1)
+.IR seg (1),
+.IR arch (3)
+.SH HISTORY
+.I Io
+first appeared in 9front (April, 2011).