How to use eMMC & uSD as boot devices on i.MX6UL custom board, boot selectable without removing other

[punitkumar]

Hi

I'm using my self made custom i.MX6UL board with 4GB eMMC chip mounted and tested successfully. Now I wish to make another board with added uSD card and an option to select any one of the two storage for booting the board.

Please help me over the same, how can i do this?

Also the selection can be based on some jumper settings, like disabling one device to use another for boot as both eMMC & uSD card are to be connected to the same ports (i found it from the EVK schematic, if there is any other possibility, please tell me as there is one more SDcard interface available).

igorpadykov‌?,YuriMuhin_ng‌?

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Punit Kumar

[punitkumar · Accepted solution]

Thanks igorpadykov YuriMuhin_ng

I found a method to use both uSD & eMMC at once by connecting eMMC to SDHC2 interface and uSD Card to SDHC1 interface.

fusebit BOOT_CFG2[3] is used to switch between uSDHC1 & uSDHC2 card as boot device.

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Punit Kumar

[chayishuang]

I'm using i.MX6UltraLite EVK board. MicroSD (USDHC-2) on the Main board, one standard SD (USDHC-1) on the Base board, MicroSD (USDHC-2) is my boot device. Now I wish to use both MicroSD and standard SD,but standard SD donnot

work.It would report this error: mmc0: error -84 whilst initialising SD card.how can i do this,standard SD works successfully.Thanks

[Yuri]

Hello,

  You should provide multiple boot option as part of own bootloader, located

on both devices. 

Regards,

Yuri.

[igorpadykov]

Hi Punit

SD interface was not designed for connecting with multiple devices, so

seems some kind of switch (like jumpers) would be option.

Best regards
igor
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