CM-T54: Linux: Debian
Overview
The example run-time Linux filesystem image for CM-T54 is based on Debian GNU/Linux Wheezy. The CompuLab Linux package for CM-T54 includes ready to run root filesystem demo archive, Linux kernel configuration and source code patches.
The default Debian Wheezy Linux image includes more than 400 software packages. Among them:
- Core system
- Debian package management system
- X11 Windowing System
- Fluxbox desktop manager
- Iceweasel browser
- Samba connectivity suite
- SSH server and client
- ALSA configuration and usage utilities
- Bluetooth tools and daemons
The CM-T54: Linux: Getting started page provides a brief introduction on how to install the run-time Linux image.
Package contents
version.txt
The contents of the version.txt identifies the package version.
images
- zImage-cm-t54 - ready to run Linux kernel image binary for CM-T54
- omap5-sbc-t54.dtb - SBC-T54 Device Tree binary
- debian-image.tar.bz2 - archive of the Debian root file system
- kernel.img - Kernel image required for installation onto the eMMC
- ramdisk.img - Ramdisk image required for installation onto the eMMC
- bootscr.img - U-Boot script used for image installation
kernel
- zImage-3.14-cm-t54-1.bin - ready to run Linux kernel version 3.14-cm-t54-1 for CM-T54
- linux-3.14-cm-t54-1.config - Linux kernel 3.14-cm-t54-1 configuration file
- linux-3.14-cm-t54-1.patch - patch vs. Linux kernel 3.14 with support for CM-T54 peripherals
- patches - ordered collection of patches, that form the single patch above (linux-3.14-cm-t54-1.patch)
utilities
The utilities directory contains miscellaneous utilities useful for development
- tftpd32.zip - TFTP server for Windows users
- eeprom-util - CompuLab EEPROM utility for reading information found inside the EEPROM on CompuLab boards
- bootscr.src - U-Boot script source used for loading kernel and ramdisk images from MMC/SD card or USB storage device
Using Debian Linux on CM-T54
Connection and Logging In
Use the following username and password to login:
Account with administrative privileges:
cm-debian login: root Password: 111111
Regular user account:
cm-debian login: user Password: 111111
To login into the Linux system, you may use a serial console (ttyO3) at 115200 bps, or connect through the network, or use a keyboard and HDMI display.
Networking
To configure networking, edit /etc/network/interfaces, /etc/resolv.conf, /etc/hostname and /etc/hosts. For more information about Debian Linux network configuration read Network setup chapter in the Debian Reference.
X Windows system
CompuLab distribution contains full featured X Windows system with Fluxbox window manager. Before starting X Windows, connect USB mouse and keyboard to the system. You can run X Windows by typing startx.
Fluxbox window manager
CM-T54 Debian Linux features installed Fluxbox package - a lightweight window manager for the X Windowing System.
- Fluxbox provides configurable window decorations, a root menu to launch applications and a toolbar that shows the current workspace name, a set of application names and the current time. There is also a workspace menu which allows you to add or remove workspaces. The slit can be used to dock small applications, e.g. most of the bbtools can use slit.
- Fluxbox can iconify windows to the toolbar, in addition to adding the window to the Icons submenu of the workspace menu.
Visit Fluxbox Wiki and Official home page for more details.
Software Management
Debian Linux image for CM-T54 includes all the information required to use Debian package management utilities. You can use apt-get and dpkg out of the box.
MMC/SD
The support for MMC/SD card on CM-T54 is built into the Linux kernel. To mount the memory card, monitor /proc/partitions to see what partitions were detected on the MMC/SD card. For example, suppose MMC/SD partition you'd like to mount is mmcblk0p1 then:
mkdir -p /mnt/mmcblk0p1 && mount /dev/mmcblk0p1 /mnt/mmcblk0p1
WiFi
CM-T54 features 802.11b/g/n wireless connectivity solution, implemented with the AzureWave AW-NH387 Wireless controller module.
WiFi Initialization
- WiFi requires no user interaction for being configured. The driver gets loaded automatically.
Make sure that the WiFi driver is loaded:
root@cm-debian:~# lsmod | grep mwifiex mwifiex_sdio 16807 0 mwifiex 166126 1 mwifiex_sdio
- iwconfig command from wireless-tools package can be used to retrieve detailed information about the WiFi interfaces:
root@cm-debian:~# iwconfig mlan0
mlan0 IEEE 802.11bgn ESSID:off/any
Mode:Managed Access Point: Not-Associated
Retry short limit:9 RTS thr=2347 B Fragment thr=2346 B
Encryption key:off
Power Management:off
- Sample WiFi scanning:
root@cm-debian:~# iwlist mlan0 scan
The output will show the list of Access Points and Ad-Hoc cells in range. For more information about connecting to wireless networks and tuning WiFi interfaces refer to “wpa_supplicant” and “wireless-tools” man pages.
Bluetooth
CM-T54 features Bluetooth 3.0 + High Speed (HS) interface. Following sections describe the initialization and simple use cases of the Bluetooth interface.
Host Controller Interface (HCI) Initialization
- HCI requires no user interaction for being configured. The driver gets loaded automatically unless this option has been disabled by putting a black list rule for this device.
Make sure that the Bluetooth driver is loaded:
root@cm-debian:~# lsmod | grep btmrvl btmrvl_sdio 10928 0 btmrvl 10562 1 btmrvl_sdio bluetooth 256992 17 btmrvl,rfcomm,btmrvl_sdio
- HCI device configuration utility can be run to retrieve detailed information about the Bluetooth interfaces:
root@cm-debian:~# hciconfig -a hci1: Type: BR/EDR Bus: SDIO BD Address: 00:00:00:00:00:00 ACL MTU: 0:0 SCO MTU: 0:0 DOWN RX bytes:202 acl:0 sco:0 events:6 errors:0 TX bytes:78 acl:0 sco:0 commands:4 errors:0 hci0: Type: BR/EDR Bus: SDIO BD Address: D0:E7:82:B5:0C:F6 ACL MTU: 1021:6 SCO MTU: 120:6 UP RUNNING PSCAN RX bytes:1700 acl:0 sco:0 events:59 errors:0 TX bytes:1479 acl:0 sco:0 commands:59 errors:0 Features: 0xff 0xee 0x8f 0xfe 0x9b 0xff 0x79 0x87 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV3 Link policy: RSWITCH HOLD SNIFF Link mode: SLAVE ACCEPT Name: 'cm-debian-0' Class: 0x6e0100 Service Classes: Networking, Rendering, Capturing, Audio, Telephony Device Class: Computer, Uncategorized HCI Version: 3.0 (0x5) Revision: 0x8300 LMP Version: 3.0 (0x5) Subversion: 0x4660 Manufacturer: Marvell Technology Group Ltd. (72)
- If the HCI device is not running, use the below command to enable the HCI device:
# hciconfig hci0 up
A2DP Headphones
- Scan for available devices to find out Headphones BT device address:
root@cm-debian:~# hcitool scan Scanning ... 00:07:A4:F2:B3:CB Motorola HT820
- Add new PCM device by editing /etc/asound.conf:
pcm.btheadphones {
type plug
slave {
pcm {
type bluetooth
device 00:07:A4:F2:B3:CB
profile "auto"
}
}
hint {
show on
description "BT Headphones"
}
}
ctl.btheadphones {
type bluetooth
}
- List device names to ensure correct settings in /etc/asound.conf:
root@cm-debian:~# aplay -L
null
Discard all samples (playback) or generate zero samples (capture)
btheadphones
BT Headphones
- Put the headphones in the pairing mode.
- Launch bluez-simple-agent application and provide device PIN code on request:
root@cm-debian:~# bluez-simple-agent hci0 00:07:A4:F2:B3:CB RequestPinCode (/org/bluez/1335/hci0/dev_00_07_A4_F2_B3_CB) Enter PIN Code: 0000 Release New device (/org/bluez/1335/hci0/dev_00_07_A4_F2_B3_CB)
- Launch aplay playback tool:
root@cm-debian:~# aplay -D btheadphones sample_audio.wav Playing WAVE 'sample_audio.wav' : Signed 16 bit Little Endian, Rate 22050 Hz, Stereo
Display options
CM-T54 evaluation platform has four video output interfaces: LCD, DVI, LVDS and HDMI. Default configuration of Debian Linux for CM-T54 uses HDMI as primary video output.
