SoM-112ES User Manual
Revision 1.00 © 2018
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2.16
Real-Time Clock
The SoM-112ES is equipped with an external battery (BH1) for backing up the module’s Real-Time Clock
(RTC). Drivers to access the RTC are included in the operating systems. Jumper JB1 should be placed in
the ON position in order to retain system time when powered down.
3
Software
The SoM-112ES offers a wide variety of software support from both open source and proprietary
sources. Software Board Support Packages (BSPs) and Linux Software Development Kits (SDKs) are
available for most SoM processor modules.
For more information on Linux Software Support, please visit the EMAC Wiki Software Section at:
http://wiki.emacinc.com/wiki/Product_wiki
3.1
Das U-Boot
EMAC utilizes Das U-Boot for its ARM based products. U-Boot is an open source/cross-architecture
platform independent bootloader. It supports reading and writing to the flash, auto-booting,
environmental variables, and TFTP. Das U-boot can be used to upload and run and/or reflash the OS
or to run stand-alone programs without an OS. Products are shipped with a valid MAC address
installed in flash in the protected U-boot environmental variable “ethaddr”. At boot time U-Boot
automatically stores this address in a register within the MAC, which effectively provides it to any OS
loaded after that point.
3.2
Embedded Linux
EMAC Open Embedded Linux (EMAC OE Linux) is an open source Linux distribution for use in
embedded systems. The EMAC OE Linux Build is based on the Open Embedded
(
www.openembedded.org
) and Yocto (
www.yoctoproject.org
) Linux build systems. Open Embedded
is a superior Linux distribution for embedded systems. Custom Linux builds are also available on
request.
The distribution contains everything a user could expect from a standard Linux kernel: powerful
networking features, advanced file system support, security, debugging utilities, and countless other
features.
The basic root file system includes:
Busybox
Hotplugging support
APM utilities for power management
Openssh SSH server
lighttpd HTTP server
JJFS2 or EXT4 file system with utilities
