ref: 75c92428225428c8fde2d015f010e608a0b12f1d
dir: purgatorio/man/3/switch
.TH SWITCH 3 MPC8xx .SH NAME switch \- hardware option switch .SH SYNOPSYS .nf .B bind -a '#r' /dev .B /dev/switch .fi .SH DESCRIPTION .PP The switch device serves a one-level directory, giving access to one read-only file, .BR switch . A read returns the value of the development board's option switch (DS1), represented as a decimal number from 0 to 15, representing four bits, each corresponding to one of the four toggles. Each toggle produces the value 0 when it is set `ON' and 1 when it is off. Toggle 1 corresponds to bit .B 1<<3 in the number, toggle 2 corresponds to bit .BR 1<<2 , and so on .SH SOURCE .B /os/mpc/devrtc.c