Re: U-Boot and legacy SPL power control on modern platforms

[Tom Rini <trini@konsulko.com>]

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On Wed, Mar 25, 2026 at 07:18:56PM +0800, Peng Fan wrote:
> Hi Tom,
> 
> On Fri, Mar 20, 2026 at 03:45:18PM -0600, Tom Rini wrote:
> >Hello,
> >
> >As part of the work I've been doing on clarifying Kconfig dependencies
> >I've stumbled on to a number of modern boards[1] that are using the
> >SPL_POWER_LEGACY symbol. Can the maintainers please update these to use
> >DM_PMIC, DM_REGULATOR (and SPL variants) as needed so that they use the
> >modern architecture, or let me know what's missing here? Thanks!
> 
> For i.MX8MQ, I think we may need to leave with SPL_POWER_LEGACY,
> the board has 256KB TCM, but u-boot-spl-ddr.bin is almost using all
> of them if enabling SPL_DM, other SPL_OF_CONTROL and other DM drivers.
> 
> u-boot-spl.bin itself is 90KB+, but ddr firmware and hdmi.bin are packed
> in u-boot-spl-ddr.bin, the image is a bit large.

Ugh. Does CONFIG_SPL_OPTIMIZE_INLINING=y win us enough space here to
matter? Changing CONFIG_SPL_LOGLEVEL rarely is enough of a win to
matter, so I don't think that'll help. Turning off CONFIG_MMC_VERBOSE
sometimes helps, but only a little.

If we really can't make it all fit, then renaming some options needs to
be done once we remove the legacy portion from full U-Boot (of which
there's a much smaller number of semi-modern platforms enabling it).
Thanks for checking on this.

-- 
Tom

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