CM-T3x: U-Boot: Custom Features - Revision history

Nikita: /* Splash screen image */

2014-03-31T10:18:11Z

‎Splash screen image

Grinberg: /* Setting the "{{parameter|displaytype}}" variable */

2013-12-03T12:31:25Z

‎Setting the "{{parameter|displaytype}}" variable

Grinberg: /* Splash screen image */

2013-05-13T11:00:03Z

‎Splash screen image

New page

== Splash screen ==

CM-T3x U-Boot features splash screen support starting from version 2013.04-cm-t3x-4. 
The support covers displays that are connected via DVI interface. 
The following setup is required to enable splash screen display:
* Connect a display to the SB-T35 as described in [http://compulab.co.il/products/computer-on-modules/cm-t3530/#devres SB-T35 reference manual]
* [[#Display parameters setup|Setup display parameters]]
* [[#Splash screen image|Store a splash screen image in the CM-T3x NAND flash]]

=== Display parameters setup ===
Configuring the U-Boot display sub-system involves passing display parameters to the OMAP3 display driver. 
U-Boot for CM-T3x provides predefined parameter sets, as well as the option to configure custom parameters according to the display data-sheet. 
U-Boot for CM-T3x display sub-system configuration is controlled by two U-Boot environment variables: the {{parameter|displaytype}} variable and the optional user defined variable for custom display settings.

==== Setting the "{{parameter|displaytype}}" variable ====
The {{parameter|displaytype}} variable can be assigned one of the following values:
* <{{parameter|preset}}> - One of the following predefined settings:
** {{parameter|dvi640x480}} - DVI interface with 640x480 resolution and 16/8 bit color depth.
** {{parameter|dvi800x600}} - DVI interface with 800x600 resolution and 16/8 bit color depth.
** {{parameter|dvi1024x768}} - DVI interface with 1024x768 resolution and 16/8 bit color depth.
** {{parameter|dvi1152x864}} - DVI interface with 1152x864 resolution and 16/8 bit color depth.
** {{parameter|dvi1280x960}} - DVI interface with 1280x960 resolution and 16/8 bit color depth.
** {{parameter|dvi1280x1024}} - DVI interface with 1280x1024 resolution and 16/8 bit color depth.
* {{parameter|none}} - U-Boot will disable the display sub-system. This is also the default behavior when the {{parameter|displaytype}} variable value is not set.
* <{{parameter|varname}}> - U-Boot will search for the "{{parameter|varname}}" environment variable and setup the display parameters as described in [[#Custom display parameter setup|Custom display parameter setup]] section.

==== Custom display parameter setup ====
Throughout this section the optional user defined variable will be called {{parameter|custom}}. 
The {{parameter|custom}} variable is a string of parameters, describing the display characteristics. 
The syntax of {{parameter|custom}} variable is a comma separated list of {{parameter|<key>:<value>}} pairs and {{parameter|<value>}} singles. For example:
<pre>
<key1>:<value1>,<key2>:<value2>,<value3>,<key4>:<value4>
</pre>
The order of the parameters in the string is not important. 

===== Parameters description =====
{|width="100%" cellpadding="3" border="1" style="border: 1px solid rgb(85, 85, 85); border-collapse: collapse;"
|-
| mode:XRESxYRES
| The display resolution in pixels: {{parameter|XRES}} - width, {{parameter|YRES}} - height.
|-
| pixclock:PIXCLOCK
| Pixel clock in '''MHz'''.
|-
| left:LEFT
| Left display margin (Horizontal Back Porch)
|-
| right:RIGHT
| Right display margin (Horizontal Front Porch)
|-
| upper:UPPER
| Upper display margin (Vertical Back Porch)
|-
| lower:LOWER
| Lower display margin (Vertical Front Porch)
|-
| hsynclen:HSYNC
| Horizontal sync time (Horizontal Sync Pulse Width)
|-
| vsynclen:VSYNC
| Vertical sync time (Vertical Sync Pulse Width)
|-
| active
| Active (TFT) display
|-
| passive
| Passive (STN) display
|-
| hsync:HSYNC
| Horizontal sync polarity. 0 => active low, 1 => active high
|-
| vsync:VSYNC
| Vertical sync polarity. 0 => active low, 1 => active high
|-
| outputen:POLARITY
| Output enable polarity. 0 => active low, 1 => active high
|-
| pixclockpol:POLARITY
| Pixel clock polarity. 0 => falling edge, 1 => rising edge
|-
| display:DISPLAY
| Target display. Currently, the only supported option is {{parameter|dvi}}.
|-
|}
All the above values should be taken or derived from the display datasheet. 
For example, to setup the parameters for a 1024x768 DVI display in {{parameter|custom}} variable, use the following commands:
<pre>
> setenv custom mode:1024x768,pixclock:65,left:160,right:24,upper:29,lower:3,hsynclen:136,vsynclen:6,hsync:0,vsync:0,outputen:1,pixclockpol:0,active,display:dvi
> setenv displaytype custom
> saveenv
</pre>

=== Splash screen image ===

U-Boot for CM-T3x supports uncompressed 8-bit and 16-bit BMP splash screen images.
An example of such an image can be found in the U-Boot for CM-T3x package ([[#See also|here]]) under {{parameter|utilities-->splash_images}} folder.
The splash screen image should be stored in the CM-T3x NAND flash at offset {{parameter|0x100000}} and its maximal size should not exceed {{parameter|1408KB (0x160000)}}.
U-Boot will automatically relocate the splash screen image from NAND flash into the OMAP3 display frame buffer. 

==== Flashing the Splash screen image into the NAND flash ====

To write the splash screen image into the NAND flash use the following command sequence:
* Download the image to the CM-T3x RAM:
<pre>
> tftp 80a00000 <bmp file name>
</pre>
* Or read the image from MMC/SD card:
<pre>
> mmc rescan
> fatload mmc 0 80a00000 <bmp file name>
</pre>
* Erase the NAND flash at offset 0x100000:
<pre>
> nand erase 100000 <bmp size>
</pre>
* Write the splash screen image into the NAND flash:
<pre>
> nand write 80a00000 100000 <bmp size>
</pre>
Now the splash screen is in the NAND flash.

==== Setting up the environment ====

To display the splash screen image, the {{parameter|splashimage}} environment variable must be set.
The {{parameter|splashimage}} variable should contain the base address for splash screen shadow in RAM.
Due to alignment restrictions, this address should be 16-bit aligned, but '''not 32-bit aligned'''. Good example is {{parameter|0x80a00002}}.
U-Boot will not accept addresses that do not satisfy this requirement, and will also refuse to load an image if it overlaps the U-Boot shadow in RAM.
To set the {{parameter|splashimage}} variable use the following command:
<pre>
> setenv splashimage 80a00002
> saveenv
</pre>

== Multiple environment storage devices ==

Starting from version 2012.07-cm-t3x-3, CM-T3x U-Boot supports storing its environment in multiple storage devices simultaneously, as well as importing and switching between the devices on the fly. This feature adds the following variant to U-Boot {{parameter|env}} command: 

<pre>env device [dev [import]]</pre>

The value of {{parameter|dev}} can be {{parameter|nand}} or {{parameter|mmc}}.

=== Using multiple environment feature ===

To see the currently active environment storage device run:
<pre>> env device</pre>
To switch to another environment storage device run (this will '''not''' change the content of the current U-Boot environment):
<pre>> env device <storage device></pre>
To switch to another environment storage device and also import the environment content from that device and replace the current U-Boot environment:
<pre>> env device <storage device> import</pre>

== See also ==
* [http://compulab.co.il/products/computer-on-modules/cm-t3730/#devres CM-T3730 U-Boot package]
* [http://compulab.co.il/products/computer-on-modules/cm-t3530/#devres CM-T3530 U-Boot package]
* [[U-Boot quick reference]]
* [[U-Boot images]]
* [[CM-T3x: U-Boot: Firmware Overview]]
* [http://www.denx.de/wiki/U-Boot/Documentation U-Boot documentation]

[[Category:U-Boot]]
[[Category:CM-T3530]]
[[Category:CM-T3730]]

@@ Line 96: / Line 96: @@
 U-Boot for CM-T3x supports uncompressed 8-bit and 16-bit BMP splash screen images.
 An example of such an image can be found in the U-Boot for CM-T3x package ([[#See also|here]]) under {{parameter|utilities-->splash_images}} folder.
-The splash screen image should be stored in the CM-T3x NAND flash at offset {{parameter|0x100000}} and its maximal size should not exceed {{parameter|1408KB (0x160000)}}.
+The splash screen image can be stored in the CM-T3x NAND flash at offset {{parameter|0x100000}}, or as a file named splashimage.bmp in an MMC/SD card that is formatted with a FAT file system. When storing the splash image on the NAND flash, its maximal size should not exceed {{parameter|1408KB (0x160000)}}.
-U-Boot will automatically relocate the splash screen image from NAND flash into the OMAP3 display frame buffer.<br>
+U-Boot will automatically relocate the splash screen image from its storage into the OMAP3 display frame buffer.<br>
-==== Flashing the Splash screen image into the NAND flash ====
+==== Flashing the splash screen image into the NAND flash ====
 To write the splash screen image into the NAND flash use the following command sequence:
@@ Line 123: / Line 123: @@
 ==== Setting up the environment ====
-To display the splash screen image, the {{parameter|splashimage}} environment variable must be set.
+To display the splash screen image, the {{parameter|splashimage}} and {{parameter|splashsource}} environment variables must be set.
-The {{parameter|splashimage}} variable should contain the base address for splash screen shadow in RAM.
+* The {{parameter|splashsource}} variable should be set to either "nand" or "mmc". If left undefined, U-Boot will default to using NAND.
-Due to alignment restrictions, this address should be 16-bit aligned, but '''not 32-bit aligned'''. Good example is {{parameter|0x80a00002}}.
+* The {{parameter|splashimage}} variable should contain the base address for splash screen shadow in RAM. U-Boot will not load an image if it overlaps the U-Boot shadow in RAM.
-U-Boot will not accept addresses that do not satisfy this requirement, and will also refuse to load an image if it overlaps the U-Boot shadow in RAM.
+To set the {{parameter|splashsource}} variable use the following command:
 To set the {{parameter|splashimage}} variable use the following command:
 <pre>
-> setenv splashimage 80a00002
+> setenv splashimage 80a00000
 > saveenv
 </pre>

@@ Line 22: / Line 22: @@
 ** {{parameter|dvi1280x960}} - DVI interface with 1280x960 resolution and 16/8 bit color depth.
 ** {{parameter|dvi1280x1024}} - DVI interface with 1280x1024 resolution and 16/8 bit color depth.
 * {{parameter|none}} - U-Boot will disable the display sub-system. This is also the default behavior when the {{parameter|displaytype}} variable value is not set.
 * <{{parameter|varname}}> - U-Boot will search for the "{{parameter|varname}}" environment variable and setup the display parameters as described in [[#Custom display parameter setup|Custom display parameter setup]] section.