Hi Michal,
On 28/03/2019 15:03, Michal Simek wrote:
On 27. 03. 19 16:38, Jean-Jacques Hiblot wrote:
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.
Patch #1 "spl: fit: Add support for applying DT overlay" has been posted a few weeks ago by Michal Simek. Patch #2 and #3 amend Michal's patch. Patch #4 and #5 are simple fixes for the Makefile Patch #6 is not required but relates to this series and will be required later by the AM6x platform Patch #7 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). This breaks buildman for several platforms because not all the binaries embedded in the FIT are available. Patch #9 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 #10 disables advanced SPL FIT features to keep the size of the SPL of the am335x_evm in check Patch #11 is not required, but demonstrates on a DRA76-evm how this series can be used.
On arm, if overlay are supported, this series increases the size of the SPL by 3-4 kB.
Changes in v2:
- reworked board_fit_get_additionnal_images() and how it used in spl_fit.c
- removed dtbo generation from dtso files and use .dts extension for the overlays
- add dynamic allocation usage in a separate patch
- defconfig change for the am335x_evm
This series looks better. Is this able to also handle different images then just dtbs?
Sorry I thought had answered this.
Yes this is able to handle different image types, not just dtbos.
Have you been able to play with it ? any additional comment ?
JJ
Thanks, Michal