The fit,load property confuses users because the load address is taken from the ELF file rather than being specified in the binman node. Document how to inspect an ELF file to find out where its segments will be loaded, using readelf, the linker script or objdump, and point at the elf_sections and elf_sections_tee test linker scripts as examples of two components placed to avoid overlapping memory. Also note that the mkimage load address overlap check works on packaged data sizes and therefore assumes uncompressed images.
Compared to the previously applied version of this change, the text now lives in the fit etype docstring. The entry documentation is produced from docstrings by the binman_docs Sphinx extension at documentation build time, so no pre-generated file needs updating. Signed-off-by: Aristo Chen <[email protected]> --- tools/binman/etype/fit.py | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/tools/binman/etype/fit.py b/tools/binman/etype/fit.py index 32caa03a7e1..4657ed1fd76 100644 --- a/tools/binman/etype/fit.py +++ b/tools/binman/etype/fit.py @@ -319,6 +319,32 @@ class Entry_fit(Entry_section): Generates a `load = <...>` property with the load address of the segment + Note: The load address comes from the ELF file's program headers. + To determine where an ELF file will be loaded, you can: + + 1. Use readelf to examine the program headers: + + ``readelf -l your_elf_file.elf`` + + Look for the LOAD segments and their VirtAddr (Virtual Address) + + 2. Check the linker script (.lds file) used to build the ELF: + look for the `. = <address>;` statements which set the location + counter and determine load addresses for different sections + + 3. Use objdump to see section addresses: + + ``objdump -h your_elf_file.elf`` + + For example, in binman tests, elf_sections.lds sets the ATF load + address to 0x00000010, while elf_sections_tee.lds sets the TEE + load address to 0x00100010 to avoid memory overlap conflicts. + + Note that the mkimage load address overlap check compares the + packaged data size of each image, so it assumes uncompressed + images: a compressed image occupies more memory after + decompression than the check accounts for. + fit,entry Generates a `entry = <...>` property with the entry address of the ELF. This is only produced for the first entry -- 2.43.0
