FIT provides a way to select between different devicetree blobs depending on the model. This works fine for U-Boot proper and allows SPL to select the correct blob for the current board at runtime. The boot sequence (SPL->U-Boot proper) is therefore covered by the existing feature set.
The first boot phase (typically TPL) cannot use FIT since SoC boot ROMs don't currently support it. Therefore the TPL image must be specific to each model it boots on.
To support booting on mulitple models, binman must therefore produce a separate TPL image for each model, even if the images for the rest of the phases are identical.
TPL needs to be packaged as an executable binary along with a reduced devicetree. When multiple models are supported, a reduced devicetree must be provided for each model.
U-Boot's build system is designed to build a single devicetree for SPL builds, so does not support this requirement.
Add a new 'alternatives' feature to Binman, allowing it to automatically subset a devicetree to produce the reduced devicetree for a particular phase for each supported model. With this it is possible to produce a separate TPL image for each of the models. The correct one can then be loaded onto a board, along with the common FIT image(s).
Signed-off-by: Simon Glass sjg@chromium.org ---
tools/binman/btool/fdtgrep.py | 2 +- tools/binman/control.py | 3 + tools/binman/entries.rst | 42 ++++++ tools/binman/entry.py | 4 +- tools/binman/etype/alternates_fdt.py | 132 +++++++++++++++++++ tools/binman/ftest.py | 121 +++++++++++++++++ tools/binman/image.py | 13 ++ tools/binman/test/328_alternates_fdt.dts | 28 ++++ tools/binman/test/329_alternates_fdtgrep.dts | 29 ++++ tools/binman/test/330_alternates_vpl.dts | 29 ++++ tools/binman/test/331_alternates_spl.dts | 29 ++++ tools/binman/test/332_alternates_inval.dts | 29 ++++ tools/binman/test/alt_dts/model1.dts | 24 ++++ tools/binman/test/alt_dts/model2.dts | 24 ++++ 14 files changed, 507 insertions(+), 2 deletions(-) create mode 100644 tools/binman/etype/alternates_fdt.py create mode 100644 tools/binman/test/328_alternates_fdt.dts create mode 100644 tools/binman/test/329_alternates_fdtgrep.dts create mode 100644 tools/binman/test/330_alternates_vpl.dts create mode 100644 tools/binman/test/331_alternates_spl.dts create mode 100644 tools/binman/test/332_alternates_inval.dts create mode 100644 tools/binman/test/alt_dts/model1.dts create mode 100644 tools/binman/test/alt_dts/model2.dts
Applied to u-boot-dm, thanks!