The purpose of this series is to provide the SPL with ability to apply overlays for u-boot. this is only a RFC so far, to get a feedback on the approach.
Our use-case is the support of the daughter boards of the AM65x EVM. In Linux, each board is supported by a unique overlay. The presence of the boards is detected at runtime, and some useful features (like USB) are implemented on those daughter boards. Instead of providing multiple dtbs and fall in a combinatorial pit, we propose to use DT overlays.
The first 4 patches are small fixes/improvement related to the build. Patch #5 may be a bit controversial. It basically replaces u-boot.img with a symlink to u-boot.itb in case we use a "complex" FIT (ie: if SPL_FIT_SOURCE or SPL_FIT_GENERATOR are set)
Patch #6 and #7 are the core support for DTB application in the SPL. Based on a patch posted by Michal Simek a few weeks ago. The list of overlays is read from the "fdt" of the configuration chosen in the ITB (same property as for the DTB): configurations { default = "conf-1"; conf-1 { description = "dra76-evm"; firmware = "firmware-1"; fdt = "fdt-1", "overlay-1"; }; }
Patch #8 adds a way to dynamically select the DT overlays. That is were we would use HW detection to select the required overlays. In that case, the board-level code tells what overlay it needs (it gives the name of the node).
Patch #9 is not required, but demonstrates on a DRA76-evm how this series can be used.
Jean-Jacques Hiblot (8): dtbo: also generate dtbo from dtso Makefile.lib: include /__symbols__ in dtb if OF_LIBFDT_OVERLAY is enabled Makefile: Fix u-boot.itb generation when building outside the source tree Makefile: Pass the board name to the FIT generator scripts Makefile: use custom ITS to build u-boot.img if SPL_FIT_SOURCE or SPL_FIT_GENERATOR are set spl: fit: Allow calling spl_load_fit_image() to only get the image size sp: fit: Allow the board to dynamically select the DTB overlays it needs. !!! TEMP !!! For demonstration only !!! DRA76: Usage of overlays in SPL
Michal Simek (1): spl: fit: Add support for applying DT overlay
Makefile | 20 ++- arch/arm/dts/Makefile | 2 +- arch/arm/dts/dra76-evm-dummy.dtso | 14 +++ arch/arm/dts/dra76-evm-dummy2.dtso | 15 +++ arch/arm/mach-imx/mkimage_fit_atf.sh | 3 +- arch/arm/mach-rockchip/make_fit_atf.py | 5 +- .../lion_rk3368/fit_spl_atf.its | 6 +- .../puma_rk3399/fit_spl_atf.its | 8 +- board/ti/dra7xx/evm.c | 30 +++++ board/ti/dra7xx/evm.its | 48 ++++++++ common/spl/spl_fit.c | 114 +++++++++++++++++- configs/dra7xx_evm_defconfig | 2 + include/spl.h | 20 +++ scripts/Makefile.lib | 7 ++ 14 files changed, 273 insertions(+), 21 deletions(-) create mode 100644 arch/arm/dts/dra76-evm-dummy.dtso create mode 100644 arch/arm/dts/dra76-evm-dummy2.dtso create mode 100644 board/ti/dra7xx/evm.its