Timesys Getting Started Guide for Intel Atom E6XX with EG20T

Contents

Introduction

This document will describe in detail the procedures for booting a Linux kernel image and mounting a root file system from a hard disk on the Intel Atom E6XX with EG20T.

This guide was tested with the Intel Atom E660 with EG20T Development Kit (Formerly Crown Bay) using the GRUB bootloader.

Please see the Additional Information section for instructions on using other bootloaders.

The following configurations are supported:

  • BIOS with Grub Bootloader (Non-UEFI)
  • BIOS with Grub2 Bootloader (Non-UEFI)
  • BIOS with SYSLINUX Bootloader
  • BLDK v2 with GRUB2 Bootloader (UEFI)

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)
  • An internet connection on the Development Host.
  • Root or sudo permission on the Development Host.
  • A copy of the Linux Kernel ( bzImage-3.4-ts-i686) 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_i686-timesys-linux-<libc>/images/ on the command line.
  • If you are booting your root file system over the network, you will need two network cards installed and configured in the Development Host. One to communicate normally with your LAN/WAN while installing host packages, the other to communicate solely with the target board.
  • An available serial port on your Development Host.

Target Requirements

To boot the Intel Atom E6XX with EG20T, you will need the following items:

  • Intel Atom E6XX with EG20T Board
  • Serial NULL Modem Cable
  • Ethernet Crossover Cable or Ethernet hub/switch and Ethernet Patch Cables

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

  1. Connect the debug port (X16 on the Crown Bay) of the board to the serial port of your workstation using the null modem cable.
  2. If you are using a cross-over cable, connect the Ethernet port of the board to the second Ethernet port of your workstation.
  3. If you are using an Ethernet hub or switch, connect the board to the hub with a straight-through Ethernet cable, then connect the hub to the second Ethernet port of your workstation.
  4. Connect the power supply to your board.

Preparing the Target

Configuring Serial Communication

The Atom E6XX with EG20T 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

Installing Boot Images to your Hard Disk

You must install the root file system, kernel image, and GRUB image to the hard disk.

If you are using a non-EFI BIOS, you should use the following guide:

https://linuxlink.timesys.com/docs/wiki/engineering/howto_install_grub_built_by_the_factory

For EFI-enabled BIOS, use the following guide:

https://linuxlink.timesys.com/docs/engineering/wiki/HOWTO_Install_GRUB2_with_EFI_support

NOTE: The default Timesys builds provide a non-EFI GRUB image by default. You must use the Desktop Factory to produce the EFI-enabled image.

Preparing the Host

No additional host setup is required to boot from hard disk.

Booting the Board

If you followed the instructions in https://linuxlink.timesys.com/docs/wiki/engineering/howto_install_grub_built_by_the_factory, your board should boot to a Linux kernel automatically. However, you may wish to modify your boot process, or enable a serial console in the kernel. These instructions detail how to manually boot a kernel from GRUB.

For more information on Grub, see http://www.gnu.org/software/grub/.

Set your Root Partition

Grub commands affect the active partitiion. In order to load your kernel, you must set your hard drive RFS partition as active.

Non-EFI Grub:

grub>set root=(hd0,1)

EFI Grub:

grub>set root=(hd0,2)

Load The Kernel

You can use kernel command load the kernel that is on the hard disk.

Example

Non-EFI Grub:

grub> linux /boot/vmlinuz-3.4-ts-i686 root=/dev/sda1 rw console=ttyS0,115200 video=vesafb vga=0x318 vmalloc=256MB

EFI Grub:

grub> linux /boot/vmlinuz-3.4-ts-i686 root=/dev/sda2 rw console=ttyS0,115200 video=vesafb vga=0x318 vmalloc=256MB

Boot The Kernel

Use the boot command to boot the loaded kernel image.

grub> boot

Additional Information

Factory Documentation

Bootloaders

There are a number of supported bootloaders on this platform. Use the following guides to use them:


pch_gbe Workaround:

pch_gbe Workaround: Community support for pch_gbe was not stable until at least 2.6.37. If you see Ethernet errors like the following, shortly after enabling networking, then one workaround is to upgrade to kernel 2.6.39 (this was 2.6.35):


kernel BUG at net/core/dev.c:1728!
invalid opcode: 0000 [#1] PREEMPT
last sysfs file: /sys/devices/virtual/tty/ttyv1/uevent
Modules linked in:

Pid: 1343, comm: udevadm Not tainted 2.6.35-ts-i686 #1 NITX-315/To be filled by O.E.M.
EIP: 0060:[] EFLAGS: 00010212 CPU: 0
EIP is at skb_checksum_help+0x42/0xde
EAX: 0000002a EBX: f6480540 ECX: 0000002a EDX: f6b74001
ESI: 0000f2e6 EDI: f6801000 EBP: f68965c0 ESP: f6b75a18
DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
Process udevadm (pid: 1343, ti=f6b74000 task=f7091860 task.ti=f6b74000)
Stack:
f6480540 00000283 f6801000 c124f442 f68965c0 f6801300 f8132180 00000009
<0> 00000000 000000e1 000000e0 f6480540 f6480540 f6883240 f6801000 c12e5c8e
<0> f6883240 c13d2110 f6969a00 f6480540 f6883240 f6801000 c12f2e9d 00000000
Call Trace:
[] ? pch_gbe_xmit_frame+0x14f/0x2f6
[] ? dev_hard_start_xmit+0x226/0x2eb
[] ? sch_direct_xmit+0x6c/0x177
[] ? dev_queue_xmit+0x217/0x3ae
...