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

[Leo Liang <ycliang@andestech.com>]

Hi Conor,

On Fri, Jul 04, 2025 at 11:40:21AM +0100, Conor Dooley wrote:
> [EXTERNAL MAIL]

> Date: Fri, 4 Jul 2025 11:40:21 +0100
> From: Conor Dooley <conor.dooley@microchip.com>
> To: Leo Liang <ycliang@andestech.com>
> CC: Conor Dooley <conor@kernel.org>, u-boot@lists.denx.de, Ivan Griffin
>  <ivan.griffin@microchip.com>, Cyril Jean <cyril.jean@microchip.com>, Tom
>  Rini <trini@konsulko.com>, Ilias Apalodimas <ilias.apalodimas@linaro.org>,
>  Simon Glass <sjg@chromium.org>, Jamie.Gibbons@microchip.com
> Subject: Re: [PATCH v2] board: mpfs_icicle: implement
>  board_fdt_blob_setup()/board_fit_config_name_match()
> 
> On Thu, Jul 03, 2025 at 06:09:53PM +0800, Leo Liang wrote:
> > 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>
> 
> Hmm, I made a mistake in the MULTI_DTB_FIT portion of this, and the
> strtok() is causing problems (I forgot about the modification in place,
> and the testcases I had used didn't catch it). Have you sent this in a
> PR yet? If you have, I'll send a fix otherwise a v3.

The PR has been sent and merged.
Could you send a fix for this?

Best regards,
Leo

> 
> Cheers,
> Conor.