Re: [PATCH v2] board: mpfs_icicle: implement board_fdt_blob_setup()/board_fit_config_name_match()

[Leo Liang <ycliang@andestech.com>]

On Mon, Jun 23, 2025 at 12:51:36PM +0100, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley@microchip.com>
> 
> The firmware on the Icicle is capable of providing a devicetree in a1 to
> U-Boot, but until now the devicetree has been packaged in a "payload" [1]
> alongside U-Boot (or other bootloaders/RTOSes) and appended to the image.
> The address of this appended devicetree is placed in a1 by the firmware.
> This meant that the mechanism used by OF_SEPARATE to locate the
> devicetree at the end of the image would pick up the one provided by the
> firmware when u-boot-nodtb.bin was in the payload and U-Boot's devicetree
> when u-boot.bin was.
> 
> The firmware is now going to be capable of providing a minimal devicetree
> (quite cut down due to severe space constraints), but this devicetree is
> linked into the firmware that runs out of the L2 rather than at the end
> of the U-Boot image.
> 
> Implement board_fdt_blob_setup() so that this devicetree can be
> optionally used, and the devicetree provided in the "payload" can be
> used without relying on "happening" to implement the same strategy as
> OF_SEPARATE expects in combination with u-boot-nodtb.bin.
> Unlike other RISC-V boards, the firmware provided devicetree is only
> used when OF_BOARD is set, so that the almost certainly more complete
> devicetree in U-Boot will be used unless explicitly requested otherwise.
> 
> Implement board_fit_config_name_match(), so that, using the firmware
> provided cut-down/minimal dtb, U-Boot can select one of several
> devicetrees when MULTI_DTB_FIT is enabled.
> 
> Enabling both MULTI_DTB_FIT and OF_BOARD will lead to a conflict
> between the two options, with the latter taking priority due to
> board_fdt_blob_setup() being executed before board_fit_config_name_match(),
> which causes gd->fdt_blob to be overwritten with a pointer to the
> minimal devicetree rather than the location of the fit image containing
> the multiple dtbs. Let MULTI_DTB_FIT take priority in this case, by
> explicitly blocking the override when MULTI_DTB_FIT is enabled.
> 
> Link: https://github.com/polarfire-soc/hart-software-services/blob/master/tools/hss-payload-generator/README.md [1]
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> ---
> 
> v2:
> - implement MULTI_DTB_FIT too
> 
> v1 was a year ago here:
> https://lore.kernel.org/u-boot/20240625090806.1787287-2-conor.dooley@microchip.com/
> 
> There was some discussion on that thread, but ultimately I didn't find
> what was mentioned to be worth implementing. Heinrich suggested to me, I
> guess on IRC or something since it's not in that thread, implementing
> MULTI_DTB_FIT, which I have done. A lot of the reason for the patch when
> I wrote it was speculative, but we have some actual users for OF_BOARD
> now - hence the v2 after about a year's gap.
> 
> CC: Ivan Griffin <ivan.griffin@microchip.com>
> CC: Cyril Jean <cyril.jean@microchip.com>
> CC: Tom Rini <trini@konsulko.com>
> CC: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> CC: Simon Glass <sjg@chromium.org>
> CC: Jamie.Gibbons@microchip.com
> CC: u-boot@lists.denx.de
> ---
>  board/microchip/mpfs_icicle/mpfs_icicle.c | 63 +++++++++++++++++++++++
>  1 file changed, 63 insertions(+)

Acked-by: Leo Yu-Chi Liang <ycliang@andestech.com>