cmos.sh

#!/bin/bash

#
#   CMOS reader in Bash
#
#   Copyright (C) 2015, ZOG Industries Inc, Dmytro S.
#   Permission to use, copy, modify, and/or distribute this software 
# for any purpose with or without fee is hereby granted, provided that 
# the above copyright notice and this permission notice appear in all 
# copies.
#
#   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 
# WITH REGARD  TO THIS SOFTWARE  INCLUDING  ALL IMPLIED WARRANTIES OF 
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE 
# FOR ANY SPECIAL, DIRECT,  INDIRECT,  OR   CONSEQUENTIAL  DAMAGES OR 
# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,  DATA OR PROFITS, 
# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 
# ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#

CMOS_CMD_PORT=0x70
CMOS_DAT_PORT=0x71

CMOS_REG_SECS=0x00
CMOS_REG_MINS=0x02
CMOS_REG_HOURS=0x04
CMOS_REG_DAY=0x07
CMOS_REG_MONTH=0x08
CMOS_REG_YEAR=0x09

read_cmos () {
    local reg=$1
    echo $reg | xxd -r | tee | dd of=/dev/port bs=1 seek=$(($CMOS_CMD_PORT))  2>/dev/null
    dd if=/dev/port bs=1 count=1 skip=$(($CMOS_DAT_PORT)) 2>/dev/null | xxd -p
}

read_date () {
    local year=`read_cmos $CMOS_REG_YEAR`   
    local month=`read_cmos $CMOS_REG_MONTH`
    local day=`read_cmos $CMOS_REG_DAY` 

    echo "20$year/$month/$day"
}

read_time () {
    local hours=`read_cmos $CMOS_REG_HOURS`
    local mins=`read_cmos $CMOS_REG_MINS`
    local secs=`read_cmos $CMOS_REG_SECS`

    echo "${hours}:${mins}:${secs}"
}

echo "$(read_date) $(read_time)"