Re: [PATCH v2 0/2] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux

[Josua Mayer]

Am 01.12.25 um 14:17 schrieb Biju Das:
>
>> -----Original Message-----
>> From: Josua Mayer <josua@xxxxxxxxxxxxx>
>> Sent: 01 December 2025 12:31
>> Subject: [PATCH v2 0/2] mmc: host: renesas_sdhi_core: support configuring an optional sdio mux
>>
>> Some Renesas SoC based boards mux SD and eMMC on a single sdio controller, exposing user control by
>> dip switch and software control by gpio.
>>
>> Purpose is to simplify development and provisioning by selecting boot media at power-on, and again
>> before starting linux.
> Does it mean, you boot with eSD mode, boot the linux with SD mode and flash the image to eMMC??
>
> and then, switch to eMMC boot mode and boot everything from eMMC??
>
>
> Or
>
> boot with eSD mode, flash emmc images at initramfs level/u-boot level
>
> and then, switch to eMMC boot mode and boot everything from eMMC??

The latter.

DIP switch decides bootloader starting from eMMC or SD.
Then u-boot has complete freedom.

Finally U-Boot shall load (and patch) DTB for either eMMC or SD.
Regardless of whether rootfs is initramfs or physical media.