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@@ -0,0 +1,45 @@ +mkubootenv +========== + +Create an U-Boot environmet image suitable for flashing. The input is a text +file containing environment variable definitions in the format “name=value”, +separeated by newlines. + +Usage +----- + +usage: mkubootenv [-s <size>] <source file> <target file> + +Options: + -s <size> set size of the target image file to <size> bytes. If <size> is + bigger than the source file, the target image gets padded with + null bytes. If <size> is smaller than the source file, an error is + emitted. + -r reverse operation: get plaintext env file (target) from binary + image file (source) + +File formats +------------ + +The U-Boot environment is stored in a simple file format, described in +include/environment.h of the U-Boot source tree as follows: + +/************************************************************************** + * + * The "environment" is stored as a list of '\0' terminated + * "name=value" strings. The end of the list is marked by a double + * '\0'. New entries are always added at the end. Deleting an entry + * shifts the remaining entries to the front. Replacing an entry is a + * combination of deleting the old value and adding the new one. + * + * The environment is preceeded by a 32 bit CRC over the data part. + * + ************************************************************************** + */ + +The input file format for mkubootenv is a simple text file containing +'name=value' pairs, separated by newlines ('\n'). This means, there are _no +newlines allowed_ inside the variable names or values. + +See the example/ directory for an example input file (uboot_env.env) and its +corresponding output file (uboot_env.bin). |