CM-T3517: Linux: Getting started

Preparation steps

• Obtain a PC workstation with a serial communication port.
• For networked installation you need to install a TFTP server on the host PC. For Windows machines we recommend TFTPD32 included in the Linux package for CM-T3517 (link below).
• Download the Linux package for CM-T3517 from CompuLab website. Unzip the package to a directory on your host workstation.
• All image files mentioned below can be found in images subdirectory
• If MMC/SD card is used for booting into U-Boot, it must be prepared as described in CM-T3x: Linux: Booting from MMC/SD card article.
• Connect the host PC to the SB-T35 base-board (connector P12) via the serial cable supplied with the evaluation kit.
• Start terminal emulation software on your PC. Set baud rate to 115200 bps, 8 bit per frame, 1 stop bit, no parity, no flow control.
• Turn on the CM-T3517 evaluation system. The U-Boot boot-loader will start and you will get a command prompt.

If the boot settings of your CM-T3517 are different than default, you may need to press and hold Ctrl-C while turning the CM-T3517 on, in order to get command prompt.

Boot from the MMC/SD card

Prepare MMC/SD card as described in CM-T3x: Linux: Booting from MMC/SD card article.

• Copy uImage-cm-t3517 from Linux package for CM-T3517 to the root directory on the first partition of the MMC/SD card (FAT (16 or 32) formatted) and rename it to uImage.
• Unpack debian-image.tar.bz2 from Linux package for CM-T3517 to the root directory on the second partition of the MMC/SD card (EXT3 formatted).

  tar -xvpf /path/to/image/debian-image.tar.bz2 -C /path/to/rootfs/ && sync

• Insert the MMC/SD card into the CM-T3517 SD card slot.
• Reset the CM-T3517 system.
• The boot from MMC/SD card will start automatically with default U-Boot environment.

Boot into the installation environment (ramdisk)

The first step in CM-T3517 Linux installation is starting the installation environment (Linux kernel and Ramdisk image). This can be done using the following media:

• MMC/SD card
• Network TFTP server

Using installation environment on MMC/SD card

• Copy kernel.img, ramdisk.img and bootscr.img from Linux package for CM-T3517 to the root directory on the first partition of the MMC/SD card. Note, the partition must be FAT (16 or 32) formatted.
• Insert the MMC/SD card into the SD socket (P13) on the SB-T35.
• Use the following U-boot commands to boot the installation environment on the CM-T3517:

CM-T3517 # mmc init
CM-T3517 # fatload mmc 0:1 80400000 bootscr.img
CM-T3517 # source 80400000

• Continue to the Install Kernel and Debian Linux Images section.

Using installation environment from TFTP server

• Connect the CM-T3517 Ethernet port to your local network.
• Put kernel.img, ramdisk.img and bootscr.img from Linux package for CM-T3517 to a location accessible by the TFTP server:

  - On Windows machine: copy kernel.img, ramdisk.img and bootscr.img to the same folder and point the TFTP server to that folder

  - On Linux machine: copy kernel.img, ramdisk.img and bootscr.img to TFTP server root directory, usually /tftpboot or /tftproot.

• You can use U-boot dhcp command to obtain IP address

CM-T3517 # dhcp

or manually set ipaddr environment variable:

CM-T3517 # setenv ipaddr <CM-T3517 ip address>

• Set serverip environment variable and save the new environment:

CM-T3517 # setenv serverip <host ip address>
CM-T3517 # saveenv

• Use the following U-boot command to boot Linux on CM-T3517:

CM-T3517 # tftp 80400000 bootscr.img && source 80400000

• Continue to the Install Kernel and Debian Linux Images section.

Install Kernel and Debian Linux Images

After the ramdisk image is loaded the Linux login prompt will appear. Login as root into the system. Use 111111 password for login:

compulab login: root
Password: 111111

The next step is installing the kernel and Debian Linux images. The following media can be used as a source for installation:

• MMC/SD Card
• USB storage device
• NFS drive

Mount the MMC/SD Card

• Copy the debian-image.ubi and the uImage-cm-t3517 from the Linux package for CM-T3517 to the root directory of any partition on the MMC/SD card. The partition can be formatted either ext2/3/4 or FAT file system.
• Insert the MMC/SD card into the SD socket (P13) on the SB-T35.
• The MMC/SD card is mounted automatically under /media/mmcblk0pX. Where X is the partition number.
• If for some reason the MMC/SD card hasn't been mounted automatically, use the following mount command:

root@compulab:~# mkdir -p /media/mmcblk0pX && mount /dev/mmcblk0pX /media/mmcblk0pX

• Continue to the Install Images section.

Mount a USB Storage Device

• Copy the debian-image.ubi and the uImage-cm-t3517 from Linux package for CM-T3517 to the root directory of any partition on the USB storage device.
• Plug the USB storage device to any port on the dual USB host connector (P17) on the SB-T35.
• The USB device is mounted automatically under /media/sdXY. Where X is the device letter and Y is the partition number.
• If for some reason the USB storage device hasn't been mounted automatically, use the following mount command:

root@compulab:~# mkdir -p /media/sdXY && mount /dev/sdXY /media/sdXY

• Continue to the Install Images section.

Mount the NFS drive

• Connect the CM-T3517 Ethernet port (connector P16 or P18 on the SB-T35) to your local network.
• Copy the debian-image-cm-t3517.ubi and the uImage-cm-t3517 from the Linux package for CM-T3517 to a directory exported through NFS.
• During Ramdisk image booting the CM-T3517 attempts to obtain an IP address using DHCP. If from some reason the IP address has not been obtained, use the following commands to obtain IP address for the CM-T3517:
  • If P18 Ethernet port is connected (Davinci EMAC Ethernet controller is used):

    export eth_device=davinci_emac.0

  • If P16 Ethernet port is connected (SMSC Ethernet controller is used):

    export eth_device=smsc911x.0

  • Obtain IP using DHCP:

    root@compulab:~#  ifup `basename /sys/devices/platform/$eth_device/net/eth?`

  • If you do not have a DHCP server, you can set a static IP address using ifconfig:

    root@compulab:~#  ifconfig `basename /sys/devices/platform/$eth_device/net/eth?` <ip address>

• Mount the NFS share containing the uImage-cm-t3517 and the debian-image.ubi files:

root@compulab:~#  mount -o nolock <host ip>:/path/to/nfs/share /mnt/net

• Continue to Install Images section.

Install Images

The installation on the NAND flash can be done using the mounted media containing the CM-T3517 Kernel and Debian Linux images.

• In this section the term /mount/point can be either of the following:
  • /media/mmcblk0pX if MMC/SD card is used, where X is the partition number.
  • /media/sdXY if USB storage is used, where X is the USB drive letter and Y is the partition number.
  • /mnt/net if NFS drive is used.

• Format the NAND flash kernel partition and write the kernel image onto it:

root@compulab:~# flash_erase /dev/mtd3 0 0
root@compulab:~# nandwrite -p /dev/mtd3 /mount/point/uImage-cm-t3517

• Format the NAND flash root filesystem partition and write Debian filesystem image onto it:

root@compulab:~# ubiformat -O 2048 /dev/mtd4 -f /mount/point/debian-image.ubi

• Continue to the After Installation section.

After Installation

• Make sure there is no MMC/SD card in the SD socket (P13) on SB-T35.
• Reset the system.

If the boot settings of your CM-T3517 are different than default, you may need to press and hold ^C while turning the CM-T3517 on, in order to get command prompt.

Boot from the NAND flash

• Set the bootargs environment variable:

CM-T3517 # setenv bootargs 'ubi.mtd=rootfs,2048 root=ubi0:rootfs rw rootfstype=ubifs console=ttyO2,115200n8 nohlt'

• To boot Linux, type:

  CM-T3517 # nboot 82000000 nand0 2a0000; bootm

The Linux kernel for CM-T3517 is shipped with built-in command line parameters that define primary console, default display settings, root device and root filesystem type. Setting U-Boot bootargs environment variable overrides default kernel command line!

• For Linux automatic boot, type:

CM-T3517 # setenv bootdelay 3
CM-T3517 # setenv bootcmd "nboot 82000000 nand0 2a0000; bootm"
CM-T3517 # saveenv
CM-T3517 # boot

Select LCD model

CM-T3517 Evaluation Kit can be equipped with either of the following LCD panels: Toppoly TDO35S or DataImage SCF0403852GGU04. Toppoly TDO35S is registered as default OMAP DSS LCD device.

To set DataImage LCD as OMAP DSS LCD device add the following boot option to the kernel command line parameters:

cm_t3x_lcd=dataimage

Select video out

Default CM-T3517 video output device is LCD. Other video output devices can be used as well:

• DVI output can be enabled by adding the following boot options to the kernel command line parameters:

omapfb.vram=1:4M vram=8M omapfb.mode=dvi:1024x768-24@60 omapdss.def_disp=dvi

• TV output can be enabled by adding the following boot options to the kernel command line parameters:

omapfb.mode=tv:ntsc omapdss.def_disp=tv

See also

• CM-T3517: Linux: Debian
• CM-T3517: Linux: Kernel
• Linux Development for ARM modules
• U-Boot for CM-T3517