Timesys Getting Started Guide for Phytec Cosmic Vybrid Development Kit


Contents

Introduction

This document will describe in detail the procedures for booting a Linux kernel image and mounting a root file system over SD on the PHYTEC Cosmic Vybrid Development Kit.

Prerequisites

Host Requirements

To properly boot a board using software from Timesys, your host machine must meet the following requirements:

  • Modern GNU/Linux Distribution. While you can use nearly any modern Linux distribution released in the last 24 months, Timesys recommends one of the following:
    • Ubuntu (Most recent release or LTS)
    • Fedora (Most recent release)
  • Root or sudo permission on the Development Host.
  • A copy of the Linux Kernel (uImage) and Root File System (rootfs.tar.gz) for the Target Board downloaded from Factory. These are found in the output directory of your online build, or in the directory build_armv7l-timesys-linux-<libc>/images/ on the command line.
  • An available serial port on your Development Host.

Target Requirements

To boot the PHYTEC Cosmic Vybrid Development Kitusing SD, you will need the following items:

  • PHYTEC Cosmic Vybrid Development Kit
  • RS232 Serial Cable
  • SD card

Once you have all of the necessary components, you should perform the following steps:

  1. Connect the top UART port of the Cosmic Vybrid to the serial port of your workstation using the RS232 serial cable.
  2. Connect the power supply to your board.

Preparing the Target

Preparing the Secure Digital Card

The Cosmic Vybrid boots from an SD card. Some kits may be shipped with one that contains a sample kernel and RFS preloaded. We will be replacing these with the kernel and RFS from Factory. If you are using a blank SD card or have trouble replacing the software on the preloaded one, see Partitioning the SD Card. Otherwise, skip directly to Writing Boot Files to the SD Card.

Before you begin, you should determine the name of your SD card on your host system. To do so:

  1. Connect the SD card to your host system. Many modern systems have SD card slots on the case, or you can purchase a USB SD Card Reader for around $15 US.
  2. Determine the device name of the SD Card. This can be done using dmesg. In the following example, the device is /dev/sdX, which contains one partition sdX1.

    $ dmesg | tail
    [88050.184080] sd 4:0:0:0: [sdX] 1990656 512-byte hardware sectors: (1.01 GB/972 MiB)
    [88050.184821] sd 4:0:0:0: [sdX] Write Protect is off
    [88050.184824] sd 4:0:0:0: [sdX] Mode Sense: 03 00 00 00
    [88050.184827] sd 4:0:0:0: [sdX] Assuming drive cache: write through
    [88050.185575] sd 4:0:0:0: [sdX] 1990656 512-byte hardware sectors: (1.01 GB/972 MiB)
    [88050.186323] sd 4:0:0:0: [sdX] Write Protect is off
    [88050.186325] sd 4:0:0:0: [sdX] Mode Sense: 03 00 00 00
    [88050.186327] sd 4:0:0:0: [sdX] Assuming drive cache: write through
    [88050.186330]  sdX: sdX1

Partitioning the SD card

If you want to use a different SD card or its contents become corrupted, you can use the fdisk tool to create two partitions on your SD card. Please note that all data on the card will be lost upon completion of these steps.
  1. Unmount the partition if it was automounted by using the umount command.
    $ umount /dev/sdX1
  2. As root, run the fdisk utility on the drive.
    $ sudo fdisk /dev/sdX
  3. In fdisk, Delete the existing partition table and create a new one using the o command.
    Command (m for help): o
    Building a new DOS disklabel with disk identifier 0x8b025602.
    Changes will remain in memory only, until you decide to write them.
    After that, of course, the previous content won't be recoverable.
  4. Create a new primary partition using the n command. The first partition will be a FAT partition for storing the boot files. 64 MB is typically more than enough for this purpose.
    Command (m for help): n
    Partition type:
       p   primary (0 primary, 0 extended, 4 free)
       e   extended
    Select (default p): p
    Partition number (1-4, default 1): 1
    First sector (2048-30679039, default 2048):
    Using default value 2048
    Last sector, +sectors or +sizeK,M,G (2048-30679039, default 30679039): +64M
  5. Set the first partition as W95 FAT32 (LBA) using the t command and entering the Hex code c.
    Command (m for help): t
    Selected partition 1
    Hex code (type L to list codes): c

  6. Set the bootable flag on the first partition using the a command.

    Command (m for help): a
    Partition number (1-4): 1

  7. Create a second primary partition using the n command. This partition will be a linux partition for storing the root filesystem. It will fill the rest of the SD card.

    Command (m for help): n
    Command action
       e   extended
       p   primary partition (1-4)
    p
    Partition number (1-4, default 2): 2
    First sector (133120-30679039, default 133120):
    Using default value 18432
    Last sector, +sectors or +sizeK,M,G (133120-30679039, default 30679039):
    Using default value 30679039

  8. Verify that the partition table is correct by using the p command. It should look similar to the following:

    Command (m for help): p                                                         
                                                                                    
    Disk /dev/sdX: 15.7 GB, 15707668480 bytes
    64 heads, 32 sectors/track, 14980 cylinders, total 30679040 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x6eaae8f8

       Device Boot      Start         End      Blocks   Id  System
    /dev/sdX1   *        2048      133119       65536    c  W95 FAT32 (LBA)
    /dev/sdX2          133120    30679039    14773960   83  Linux

  9. This step will destroy all data on the SD Card - Write the partition table to the card using the w command.

    Command (m for help): w
    The partition table has been altered!

    Calling ioctl() to re-read partition table.

    WARNING: If you have created or modified any DOS 6.x
    partitions, please see the fdisk manual page for additional
    information.
    Syncing disks.

  10. Format the first partition of the SD card with a FAT filesystem using the mkfs.vfat tool.

    $ sudo /sbin/mkfs.vfat -n boot /dev/sdX1

  11. Format the second partition using an ext3 filesystem using the mkfs.ext3 tool.

    $ sudo /sbin/mkfs.ext3 -L rfs /dev/sdX2

Writing Boot Files to the SD Card

Once you have a properly partitioned SD card, you can then populate it with the boot files generated by Factory.

  1. Mount the partitions. You can remove and reinsert the card to trigger the automount, or you can use the mount command to mount the partition to an arbitrary location.

    $ sudo mount /dev/sdX1 /media/boot
    $ sudo mount /dev/sdX2 /media/rfs

  2. Transfer the U-Boot binary (u-boot.imx) to your SD card. In Desktop Factory, this file is located at: build_armv7l-timesys-linux-<libc>/images/bootloaders/u-boot.imx.

    sudo dd if=u-boot.imx of=/dev/sdX bs=512 seek=2

  3. Copy the kernel to the SD card.
  4. If you are booting the 3.0 kernel, run the following:

    sudo cp /path/to/factory/build_armv7l-timesys-linux-<libc>/images/uImage-3.0-ts-armv7l /media/boot/

    Or, if you are booting the 3.13 kernel, run the following instead:

    sudo cp /path/to/factory/build_armv7l-timesys-linux-<libc>/images/uImage-ts-armv7l /media/boot/
    sudo cp /path/to/factory/build_armv7l-timesys-linux-<libc>/images/ /media/boot/

  5. As root, extract the RFS tarball onto the SD card:

    sudo tar -xf rootfs.tar.gz -C /media/rfs/

  6. Unmount the partitions:

    sync
    cd /media/
    sudo umount boot/
    sudo umount rfs/

Remove the SD Card from your host, and slide it into the slot of your Cosmic Vybrid. You should hear the card 'click' into place.

Configuring Serial Communication

The Cosmic Vybrid uses a serial debug port to communicate with the host machine. The commands discussed in this section are meant to be performed by a privileged user account. This requires the root login or prepending each command with sudo.

Using Minicom

  1. Start minicom on your host machine in configuration mode. As root:

    # minicom -o -s -w

  2. A menu of configuration should appear. Use the Down-arrow key to scroll down and select the Serial port setup option, and press Enter.
  3. Verify that the listed serial port is the same one that is connected to the target board. If it is not, press A, and enter the correct device. This is /dev/ttyS0 on most Linux distributions.
  4. Set the Bps/Par/Bits option by pressing the letter E and using the next menu to set the appropriate values. You press the key that corresponds to the value 115200, then press Enter.
  5. Set Hardware flow control to No using the F key.
  6. Set Software flow control to No using the G key.
  7. Press Enter to return to the main configuration menu, and then press Esc to exit this menu.
  8. Reset the board, and wait for a moment. If you do not see output from the board, press Enter several times until you see the prompt. If you do not see any output from the board, and have verified that the serial terminal connection is setup correctly, contact your board vendor.

TIP: If you experience an error similar to Device /dev/ttyS0 is locked when starting minicom, it usually means that another process is using the serial port (which is usually another instance of minicom). You can find the process that is currently using the serial port by executing the following:

# fuser /dev/ttyS0
/dev/ttyS0:         28358

# ps 28358
  PID TTY      STAT  TIME COMMAND
  28923 pts/0    S+    0:00 minicom

This process can also be killed directly with fuser as root. Please use this command with caution:

# fuser -k /dev/ttyS0

Using GNU Screen

To quickly connect to a board using Gnu Screen, execute the following:

# screen /dev/ttyS0 115200

For more information about using screen, please consult the man page, or view the manual online at http://www.gnu.org/software/screen/manual/screen.html

Preparing the Host

There is no further host setup required for booting the PHYTEC Cosmic Vybrid Development Kit.

Booting the Board

Boot from SD

Power on the board and at the boot countdown, hit <Enter>

> setenv bootcmd fatload mmc 0:1 0x81000000 uImage-3.0-ts-armv7l\;bootm 0x81000000
> setenv bootargs mem=256M console=ttymxc1,115200 root=/dev/mmcblk0p2 rw rootwait
> saveenv

Reboot the board.

Additional Information

Factory Documentation