~~NOTOC~~

===== U-Boot Tools =====

U-Boot provides two tools to read **fw_printenv** and  edit **fw_setenv** the U-Boot environment from the Linux shell.   The U-Boot tools are selected by default in PTXdist based BSP's. This tutorial describes how to setup the configuration file and the usage of the tools mentioned above.  

<WRAP round info 90%>Working with U-Boot tools requires that the U-Boot environment has been saved with the ''saveenv'' command in U-Boot, otherwise the U-Boot tools are using the default environment.\\      
If a redundant environment is configured the ''saveenv'' command must be executed twice.</WRAP>


==== Customising The Config File ====

The U-Boot Tools need a proper configuration of environment size and memory offset in the /etc/fw_env.config file. \\  In case of a unmanaged memory (e.g. SPI NOR) the block size also has to be configured. The example configurations below refers to the default partitioning of our BSP's.  


++++TQMa7x |
===eMMC===
<code>
# THIS IS VALID FOR TQMa7 eMMC only!
# eMMC Block device access
/dev/mmcblk0            0x100000        0x2000
# if using with redundant env
/dev/mmcblk0           0x102000        0x2000
</code>

===SD Card===
<code>
# THIS IS VALID FOR TQMa7 SD-card only!
# eMMC Block device access
/dev/mmcblk1            0x100000        0x2000
# if using with redundant env
/dev/mmcblk1           0x102000        0x2000
</code>
++++

++++TQMa6UL |
===eMMC===
<code>
# THIS IS VALID FOR TQMa6UL eMMC only!
# eMMC Block device access
/dev/mmcblk0           0x100000        0x2000
# if using with redundant env
/dev/mmcblk0           0x102000        0x2000
</code>

===SD Card===
<code>
# THIS IS VALID FOR TQMa6UL SD-card only!
# eMMC Block device access
/dev/mmcblk1           0x100000        0x2000
# if using with redundant env
/dev/mmcblk1           0x102000        0x2000
</code>
++++

++++TQMa6x |
===eMMC===
<code>
# THIS IS VALID FOR TQMa6x eMMC only!
# eMMC Block device access
/dev/mmcblk0           0x100000        0x2000
# if using with redundant env
/dev/mmcblk0           0x102000        0x2000
</code>

===SD Card===
<code>
# THIS IS VALID FOR TQMa6x SD-card only!
# eMMC Block device access
/dev/mmcblk1           0x100000        0x2000
# if using with redundant env
/dev/mmcblk1           0x102000        0x2000
</code>
++++

++++TQMa28 |
===eMMC===
<code>
# THIS IS VALID FOR TQMa28 eMMC only!
# eMMC Block device access
/dev/mmcblk0           0x400           0x1FC00
</code>
===SD Card===
<code>
# THIS IS VALID FOR TQMa28 SD-card only!
# eMMC Block device access
/dev/mmcblk1           0x400           0x1FC00
</code>
++++

++++TQMLS102xA |
===eMMC and SD Card=== 
<code>
# THIS IS VALID FOR TQMLS102xA SD-Card and eMMC!
# eMMC Block device access
/dev/mmcblk0            0x100000        0x8000
# if using with redundant env
/dev/mmcblk0            0x108000        0x8000
</code>
===SPI NOR===
<code>
# THIS IS VALID FOR TQMLS102xA SPI NOR only!
/dev/mtd1              0x100000         0x8000          0x10000
</code>
++++
==== Using U-Boot Tools ====

== Read U-Boot Environment ==
<code>
fw_printenv
</code>


== Edit U-Boot Environment ==
<code>
fw_setenv [parameter] [value]
</code>

++++Example |

This sets the value of the bootdelay paramter in your environment to 3 
<code>
fw_setenv bootdelay 3
</code>++++