Accessing the System
20NM50-00 E2
2016-05-17
Page 45
3.4.4
Temperature Sensor
The NM50 is assembled with a temperature sensor. The temperature can be read from
the CLI.
»
Get temperature with the sensors tool:
»
Get temperature via sysfs:
3.4.5
EEPROM
The NM50 is equipped with a Board Information EEPROM. The EEPROM data can be
accessed from the CLI.
»
Read from EEPROM:
»
Write to EEPROM:
3.5
Firmware Update
3.5.1
Firmware Boot
The firmware image is loaded and started by U-Boot, which initializes basic HW parts
(e.g. SDRAM, physical address mapping, watchdog...). Various settings and parameters
are passed to the kernel (e.g. baud-rate, network settings...). U-Boot can load the kernel
image from boot-flash, network, external USB stick, etc. The kernel parameter line
(bootargs) has to be set-up in U-Boot. U-Boot commands (e.g. editenv, saveenv, printenv)
can be used to set-up kernel and other parameters.
root@OpenWrt:/#
sensors
lm75
‐
i2c
‐
0
‐
4d
Adapter:
MPC
adapter
at
0xff703000
temp1:
+35.5
C
(high
=
+80.0
C,
hyst
=
+75.0
C)
root@OpenWrt:~#
cat
/sys/class/i2c
‐
dev/i2c
‐
0/device/0
‐
004d/hwmon/
hwmon0/temp1_input
35500
root@OpenWrt:~#
cat
/sys/bus/i2c/devices/0
‐
004d/hwmon/hwmon0/
temp1_input
35500
root@OpenWrt:/#
xxd
‐
l
32
/sys/bus/i2c/drivers/at24/0
‐
0054/eeprom
0000000:
ec01
0000
0000
001d
0153
4332
3900
0000
.........SC29...
0000010:
3341
0000
0000
0000
ffff
ffff
ffff
ffff
3A..............
root@OpenWrt:/#
echo
nm50
‐
eeprom
‐
test
>
/sys/bus/i2c/drivers/at24/0
‐
0054/eeprom
This will overwrite production data stored in the EEPROM!
See
U-Boot Architecture Specification
for more information.
