---------------------------------------------------------------------
File:      readme.txt
Content:   Information about this project
Author:    GW/ georg.waibel@sensor-technik.de
---------------------------------------------------------------------

This tool can be used to create a update image file for the STW Uboot update
mechanism. It compiles a number of images (kernel, rootfs, fdt..) into one 
update image file. The update image file can be generated under a Linux 
environment (e.g. Ubuntu).

To launch the tool type:
# ./make_udimg

The content of the update image file is defined in the configuration file 
"udimage.cfg". 
The example configuration supplied with this tool expects all source image 
files in a folder "data", located in this directory.

Here is a list of the configuration options:
================================================================================
Config Option       Requirement  Description
================================================================================
result_file         mandatory    File name of the resulting update image
image_description   optional     Some text to describe the image, not used 
                                 during the update
password            mandatory    Password to check against password in UBoot 
                                 environment varibales
imgX_name           mandatory    Name of the data image (e.g. kernel_v1.23r4)
                                 Caution: max. length is 15 characters
imgX_description    optional     Some text to describe the image data, not used 
                                 during the update
imgX_file           mandatory    Path / Filename to image source data (e.g. to 
                                 kernel image)
imgX_type           optional     Type of image; not required for data image, 
                                 must be set to "script" for UBoot script image
imgX_addr           mandatory /  Flash address for image data; not required 
                    optional     for UBoot script image 
imgX_size           optional     Size of flash area to be erased (in bytes)
                                 If not specified, only as many flash sectors as 
                                 required to store the image are erased (default 
                                 behavior). In some cases this is not sufficient. 
                                 E.g. for the rootfs ( UBIFS format) it is 
                                 necessary to erase not only the space required 
                                 for the image but to erase the whole rootfs 
                                 flash area. This is because the rootfs image 
                                 auto-expands to the complete rootfs flash area 
                                 (whole mtd block). This fails if the flash 
                                 sectors are not blank.
                                 Specifying this parameter makes sure that a 
                                 defined flash area is erased, independent from 
                                 the image size.
================================================================================
imgX_ must be replaced by the image number, starting at 1. Up to 10 images can 
be compiled into a update image file. The UBoot updater can process all images 
but only the result for the first 5 images is stored in the update status 
structure in the EEPROM.

The source file for a UBoot script can be a plain text file containing the UBoot 
commands or a UBoot script image file (see UBoot documentation for details).


