There is definitely an active serial port with a login program waiting patiently for someone to login in.
Code:
root@ereader:/usr/bin# ps -ef
root 691 1 0 00:35 ttyS2 00:00:00 /sbin/getty -L ttyS2 115200 vt100
It is hooked to /dev/ttyS2
Code:
root@ereader:/usr/bin# ls -l /dev/ttyS2
crw--w--w- 1 root root 4, 66 Oct 25 00:35 /dev/ttyS2
Driver information from /proc.
Code:
root@ereader:/proc/tty/driver# cat serial
serinfo:1.0 driver:5.05c revision:2001-07-08
0: uart:PXA UART port:F8100000 irq:15 baud:19200 tx:4 rx:5159 RTS|CTS|DTR|DSR|CD|RI
1: uart:PXA UART port:F8200000 irq:14 tx:0 rx:0
2: uart:PXA UART port:F8700000 irq:13 baud:115200 tx:13308 rx:0 RTS|DTR
The tx count goes up over time as the getty program times out and re-issues the login prompt.
My guess is that UART #0 is the Wacom interface.
More information on getty and what it does:
http://www.tldp.org/HOWTO/Text-Terminal-HOWTO-14.html