Figure 4: Experimenting with the device driver

Figure 4: Experimenting with the device driver

$ echo "Help I am trapped in the kernel" > /dev/PressureSensor
$ cat /dev/PressureSensor
Help I am trapped in the kernel

$ IoControl -dev /dev/PressureSensor -dump
Data returned:
Diagnostics report:
Size: 32, Offset (seek position): 0

$ IoControl -dev /dev/PressureSensor -seek-forward 10
Data returned:

$ IoControl -dev /dev/PressureSensor -dump
Data returned:
Diagnostics report:
Size: 32, Offset (seek position): 10

$ cat /dev/PressureSensor
trapped in the kernel
$ cat /dev/PressureSensor
Help I am trapped in the kernel