Grinberg: /* Default Environment */

2012-03-05T11:17:40Z

‎Default Environment

Shai at 14:18, 15 December 2009

2009-12-15T14:18:47Z

Mike: 1 revision(s)

2009-11-15T09:18:12Z

1 revision(s)

Mike: /* See also */

2009-11-15T09:12:06Z

‎See also

Mike: 1 revision(s)

2009-07-01T14:49:21Z

1 revision(s)

Mike: /* Updating U-Boot */

2009-06-30T13:24:02Z

‎Updating U-Boot

New page

== Overview ==
The Exeda uses the U-Boot boot-loader for low-level initialization and operating system loading.
U-Boot is an open source boot-loader available for a wide range of embedded processor architectures.
This page summarizes settings and features unique to the Exeda port of U-Boot. Comprehensive documentation of the U-Boot project may be found at http://www.denx.de/wiki/view/DULG/UBoot.
The CompuLab U-Boot version for the Exeda is checked out from '''U-Boot-1_2_0''' of [http://git.denx.de/?p=u-boot.git;a=summary Das U-Boot repository] and can be obtained from [http://www.compulab.co.il/exeda/html/exeda-developer.py CompuLab website] in binary form.
CompuLab U-Boot source will be provided on request.

== Exeda specific U-Boot commands ==
A brief U-Boot command reference can be found [[U-Boot quick reference|here]].
The following commands are specific to the Exeda port of U-Boot:

* CPU frequency scaling
*: {{cmd|cpufreq}} with no arguments - display the current frequency setting
*: {{cmd|cpufreq <frequency>}} - set CPU frequency; (allowed frequency values : 104/208/312/520)
* Hardware configuration information *
*: {{cmd|hwinfo}} - print device hardware configuration information

== Default Environment ==

U-Boot features an extensive default environment, for boot sequence control and hardware configuration.

{| cellpadding="3" border="1" style="border: 1px solid rgb(85, 85, 85); border-collapse: collapse;"
! Variable
! Default setting
! Description
|-
| bootcmd
|
| This variable defines a command string that is automatically executed when the initial countdown is not interrupted.
|-
| bootdelay
| 3 sec
| Delay before automatic boot starts
|-
| boot_mode
| uboot
| Boot option setting. See [[#section 5]] for details.
|-
| bootargs
|
| The contents of this variable are passed to the Linux kernel as boot arguments
|-
| stdin
| serial
| Standard input stream
|-
| stdout
| serial
| Standard output stream
|-
| stderr
| serial
| Standard error stream
|-
| baudrate
| 115200
| Serial port baud rate
|-
| ethaddr
| set at production time
| Ethernet MAC address for the extender board ethernet interface
|-
| ipaddr
| -
| IP address; needed for tftp command
|-
| serverip
| -
| Server address; needed for tftp command
|-
| autoload
| no
| Determines whether the "dhcp", "bootp" and "rarpb" commands will automatically download an image.
|-
| splashimage
| 0x000B0000
| Address of a bitmap image used as splash-screen.
|-
| usb_mode
| slave
| USB port operation mode. The only values allowed are: "slave" or "host". Must be set before "usb start" command is issued.
|-
| extpwr_mode
| on
| Determines whether the external power enable (GPIO<97>) is asserted.
|-
| cpu_freq
| maximum supported by CPU
| CPU frequency. Used by "cpufreq" command to store the frequency setting.
|-
| mem_zero
| on
| Determines whether memory zeroing is performed. Allowed values: "on", "off".
Set to "off" for shorter boot time.
|}

== Boot Sequence Options ==

=== Boot Options ===
The U-Boot boot-loader supports several basic boot options.
The environment variable "boot_mode" determines which boot sequence is executed.
The variable may be set to the following values:

* {{parameter|uboot}} - the Exeda boots up to the U-boot command prompt.
* {{parameter|linux}} - the default Linux boot from NAND sequence is executed. Please see Linux documentation for details.
* {{parameter|wince}} - the default WinCE boot from NAND sequence is executed. Please see WinCE documentation for details.
* {{parameter|any other value}} - the command stored in the {{parameter|bootcmd}} variable is executed.

=== Bringing to Default State ===
Pressing and holding {{parameter|Ctrl D}} during the boot process will restore the U-Boot settings to the default factory values. Use this if the environment has been corrupted.

=== O/S Update Boot Sequence ===
Pressing the {{parameter|ON/OFF}} button for more than four seconds during the boot process will put the system into the O/S update boot sequence. The boot-loader will attempt to detect an external storage device (USB or MMC) and search for updated image files. If no files are detected, the system will boot up to the U-Boot command prompt. This boot mode allows easy and fast software updates without connecting a PC host.
Please refer to O/S manuals for specific update procedures.

=== NAND Flash System ===
The Exeda port of U-Boot supports the MTD flash driver that is used with the Linux O/S.
U-Boot will load the appropriate driver according to the {{parameter|boot_mode}} environment variable. Additionally, the {{parameter|nand_mode}} environment variable may be used to set the NAND driver mode explicitly. Setting {{parameter|nand_mode}} to {{parameter|on}} will cause U-Boot to load the MTD driver. If {{parameter|nand_mode}} is set to {{parameter|off}} the MTD driver will not be loaded. See WinCE documentation for further details.

== Updating U-Boot ==

{{Warning| Do not interrupt the process or shut down the system during update. Doing so can result in a disabled Exeda device that will need to be shipped to CompuLab for reprogramming}}

=== Update through serial port (preferred method) ===

* Start terminal emulation program on your PC using the serial port to which the supplied serial cable is connected. Set baud rate to 115200 bps, 8 bit per frame, 1 stop bit, no parity, no flow control.
* Turn on the Exeda. U-Boot will start and you will get a command prompt.
* Use the {{cmd|loadb}} command to start image download
<pre>
U-Boot> loadb a0010000
</pre>
* In a terminal emulation program, send the U-Boot image file using kermit mode. For example, in HyperTerminal, use {{cmd|"Transfer >> Send File"}}. A {{parameter|"Send File"}} dialog will appear. In the protocol combo box, choose Kermit. Fill in the U-Boot image filename and press the {{parameter|"Send"}} button.
*: [[Image:Hyperterm_kermit_send.png]]
* Use the following commands to store the downloaded image into the Exeda NOR flash:
<pre>
U-Boot> protect off 0 +50000
U-Boot> erase 0 +50000
U-Boot> cp.b a0010000 0 50000
</pre>
* Reboot the Exeda.

=== Update through USB and Disk-on-Key ===
A USB flash drive is needed for this procedure.
* On the host PC, copy the {{filename|u-boot-x.x.x.bin}} file to the USB flash drive. Rename the file {{filename|u-boot.bin}}.
* Connect the USB flash drive to the Exeda OTG USB port using the supplied "USB-A receptacle to Mini-USB A male" cable.
* Start a terminal emulation program on your PC using the serial port to which the supplied serial cable is connected. Set baud rate to 115200 bps, 8 bit per frame, 1 stop bit, no parity, no flow control.
* Turn on the Exeda. U-Boot will start and you will get a command prompt.
* Enable the U-Boot USB host subsystem:
<pre>
U-Boot> setenv usb_mode host
U-Boot> usb start
</pre>
* After U-Boot has detected the USB storage device copy U-Boot image to the Exeda RAM:
<pre>
U-Boot> fatload usb 0 a0010000 u-boot.bin
</pre>
* Use the following commands to store the U-Boot image into the Exeda NOR flash:
<pre>
U-Boot> protect off 0 +50000
U-Boot> erase 0 +50000
U-Boot> cp.b a0010000 0 50000
</pre>
* Reboot the Exeda.

=== Update through LAN / TFTP ===
The Ethernet extender board ("Y" option) is needed for this procedure.
* Install TFTP service (or server) on the host PC. The TFTP server tested by Compulab is TFTPD32, http://tftpd32.jounin.net, it is also included in the Linux and WinCE distribution packages.
* Rename the {{filename|u-boot-x.x.x.bin}} file to {{filename|u-boot.bin}} and copy it to the TFTP directory.
* Start a terminal emulation program on your PC using the serial port to which the supplied serial cable is connected. Set baud rate to 115200 bps, 8 bit per frame, 1 stop bit, no parity, no flow control.
* Turn on the Exeda. U-Boot will start and you will get a command prompt.
* Type {{cmd|printenv}} in order to check the current IP settings. Modify them if needed using the {{cmd|setenv ipaddr}} and {{cmd|setenv serverip}} commands. Or, use U-Boot's DHCP capability to automatically set the IP address.
* Download U-Boot image to the Exeda RAM:
<pre>
U-Boot> tftp a0010000 u-boot.bin
</pre>
* Use the following commands to store the downloaded image into the Exeda NOR flash:
<pre>
U-Boot> protect off 0 +50000
U-Boot> erase 0 +50000
U-Boot> cp.b a0010000 0 50000
</pre>
* Reboot the Exeda.

== Memory Map ==
=== NOR Flash ===

{{Important|The NOR flash memory is used to store the U-Boot image, the U-Boot environment and Exeda setup data for wireless interfaces. Corruption of this data can result in a disabled Exeda device that will need to be shipped to CompuLab for reprogramming.}}

{| cellpadding="3" border="1" style="border: 1px solid rgb(85, 85, 85); border-collapse: collapse;"
! Memory Address range
! Block Range
! Size
! Usage
|-
| 0x00000000 - 0x0004FFFF
| 1 - 5
| 320KB
| U-Boot bootloader
|-
| 0x00050000 - 0x0005FFFF
| 6
| 64KB
| U-Boot environment
|-
| 0x00060000 - 0x0006FFFF
| 7
| 64KB
| Setup block
|-
| 0x00070000 - 0x000AFFFF
| 8 - 11
| 256KB
| Utilities and applications
|-
| 0x000B0000 - 0x000FFFFF
| 12 - 16
| 320KB
| Splash-screen
|}

=== SDRAM Memory ===

SDRAM map: SDRAM starts at 0xA0000000; maximum is 0xA8000000 (128MB).

U-Boot system: 0xA7800000 ...... SDRAM top

U-Boot operates with a virtual memory subsystem turned on, using one-to-one virtual to physical address mapping.

== See also ==
* [[U-Boot quick reference]]
* [http://www.denx.de/wiki/U-Boot/Documentation U-Boot documentation]
* [[Exeda Linux]]

← Older revision		Revision as of 14:18, 15 December 2009
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	* [http://www.denx.de/wiki/U-Boot/Documentation U-Boot documentation]		* [http://www.denx.de/wiki/U-Boot/Documentation U-Boot documentation]
	* [[Exeda Linux]]		* [[Exeda Linux]]
		+
		+
		+	[[Category:U-Boot]]
		+	[[Category:EXEDA]]

@@ Line 35: / Line 35: @@
 | boot_mode
 | uboot
-| Boot option setting. See [[#section 5]] for details.
+| Boot option setting. See [[#Boot Sequence Options|Boot Sequence Options]] for details.
 |-
 | bootargs
@@ Line 94: / Line 94: @@
 Set to "off" for shorter boot time.
 |}
 == Boot Sequence Options ==

← Older revision	Revision as of 09:18, 15 November 2009
(No difference)

@@ Line 230: / Line 230: @@
 == See also ==
 * [[U-Boot quick reference]]
 * [http://www.denx.de/wiki/U-Boot/Documentation U-Boot documentation]
 * [[Exeda Linux]]

← Older revision	Revision as of 14:49, 1 July 2009
(No difference)

U-Boot for Exeda - Revision history

Grinberg: /* Default Environment */

Shai at 14:18, 15 December 2009

Mike: 1 revision(s)

Mike: /* See also */

Mike: 1 revision(s)

Mike: /* Updating U-Boot */