OpenBTS: E110 Install Image di MicroSD
General Information
OpenBTS on the E100 requires 52 MHz clocking and the use of the 52 MHz transceiver implementation due to constrained resources of an embedded system. The E100 master clock rate is configurable through the UHD driver interface and requires no hardware modifications for use with OpenBTS. The E100 includes a TCXO that keeps the master clock and RF signals within a couple of parts per million, and no external clocking is necessary for basic testing and non-carrier grade applications.
OpenBTS on the E100 is project undergoing continuing development, but has been repeatedly tested in lightly loaded scenarios - up to two simultaneous voice calls - over extended durations (multiple days) on all four GSM frequency bands. Please see the limitations section and the performance page for more information.
There are multiple ways to setup an OpenBTS environment on the E100. OpenBTS has a small number of dependent packages, which can be built from source on the device, cross-compiled with OpenEmbedded, or supplied on a pre-built filesystem image.
Using the pre-built images with all dependencies installed and compiling only OpenBTS on the device is strongly recommended for the majority of users and developers not interested in setting up a cross-compile environment.
E100 FAQ http://code.ettus.com/redmine/ettus/projects/usrpe1xx/wiki/FAQ
Updating the boot files http://code.ettus.com/redmine/ettus/projects/usrpe1xx/wiki/BootFiles
Backing up the SD card http://code.ettus.com/redmine/ettus/projects/usrpe1xx/wiki/FAQ#How-do-I-backup-the-microSD-card-shipped-with-the-E1XX
Preparing a new (not E100 supplied) SD card http://www.gumstix.org/create-a-bootable-microsd-card.html
Prebuilt Images
MLO: The stage 1 boot loader that configures external memory and loads the second stage boot loader. http://dl.dropbox.com/u/14618236/MLO
U-Boot: The stage 2 boot loader that loads the Linux kernel. http://dl.dropbox.com/u/14618236/u-boot.bin-for-3.0.bin
uImage: The Linux kernel http://dl.dropbox.com/u/14618236/uImage-3.0-pm-r0a-usrp-e1xx.bin
Root file system http://dl.dropbox.com/u/14618236/console-openbts-devel-image-usrp-e1xx.tar.gz
Installing Images
The following instructions apply to installing images on the SD card in a Linux environment. Please read all instructions and follow them carefully as significant data loss is possible. It is recommended that you backup your SD card contents before proceeding.
Insert the SD card into a card reader. On most Linux distributions, two partitions should mount automatically as "FAT" and "rootfs". If not, the partitions need to be mounted manually. The FAT partition contains required boot contents, which includes the Linux kernel. The rootfs partition contains everything else - kernel modules, installed packages, user information, etc.
$ ls /media/ FAT rootfs
Install the MLO. Always copy a new MLO over the old one. If not performed properly, the partition will need to be reformatted.
$ cd /media/FAT $ cp <download location>/MLO MLO
Install the U-Boot image and Linux kernel
$ cp <download location>/u-boot.bin-for-3.0.bin u-boot.bin $ cp <download location>/uImage-3.0-pm-r0a-usrp-e1xx.bin uImage
Erase the existing root filesystem. Make sure that the correct directory is specified as significant data loss may occur if performed improperly.
$ sudo rm -rf /media/rootfs/*
Install the new root filesystem in the mounted rootfs partition.
$ cd /media/rootfs $ sudo tar xvfz <download location>/console-openbts-devel-image-usrp-e1xx.tar.gz .
Unmount the partitions. Note that the umount may take a few minutes to sync before the SD card can be safely removed.
$ cd /media $ umount FAT $ umount rootfs
At this point, the SD card can be removed and booted on the E100. For general information on starting and communicating with the E100, please refer to the following Connections section of the FAQ. Download
Obtain the source code from the official OpenBTS P2.8 project site
svn co http://wush.net/svn/range/software/public
Build
Follow standard build instructions, however, note that special compiler options specific to ARM processor optimizations are required.
$ autoreconf -i $ ./configure --with-uhd CFLAGS="-march=armv7-a -mtune=cortex-a8 -mfpu=neon -mfloat-abi=softfp -O3" CXXFLAGS="-march=armv7-a -mtune=cortex-a8 -mfpu=neon -mfloat-abi=softfp -O3" $ make