SD is not visible when booting from eMMC

dstepanov — Mon, 07 Nov 2022 12:46:30 GMT

Hello! I'm using Solidrun's ClearFog carrier board with LX2160A Computer on a module (https://www.solid-run.com/embedded-networking/nxp-lx2160a-family/cex7-lx2160/ )

When booting from internal eMMC flash SD card inserted into carrier board is not visible.

There is a corresponding question on solidrun's community forum https://community.solid-run.com/t/sd-mmc0-not-accessible-if-booting-from-emmc/361 but it was suggested to redirect this question to NXP community.

I’ve done some investigations and the results look weird for me.
I guess that the problem resides in RCW or internal boot logic (or something else which i don’t know).
IIC2_PMUX[354-352] RCW configuration’s bits are responsible for multiplexing SDHC1 CD (card detect) pin with other controllers (I2C, GPIO, flextimer).
RCW source code (lx2160acex7/configs/lx2160a_defaults.rcwi) sets IIC2_PMUX=6 which means that SDHC1 CD pin is enabled.

I checked that these bits are really set inside FLASH memory, then i booted to u-boot and checked the content of “Reset Configuration Word Status Register 12 (RCWSR12)” which stores the content of RCW IIC2_PMUX[354-352] after reset (see 9.3.29 of User’s Manual) and this register contained all zeros which means that CPU uses II2C instead of SDHC1:

=> md.l 1E0012c 1
01e0012c: 00000000

So my guess that when you select “boot from SD card” LX2160A forces SD controller initialization (including configuration Card Detect pin) and everything goes OK. But when you boot from another source (eMMC, SPI Flash) RCW configuration comes into play and SD card does not work.

Are my suggestions correct or i'm doing something wrong? Is there any way to overcome this problem?

Thanks!

Re: SD is not visible when booting from eMMC

Chavira — Tue, 08 Nov 2022 16:02:53 GMT

Thank you for contacting NXP support!

You can view a Quick Start Guide for LX2160A on our board.

LSDK Quick Start Guide for LX2160ARDB Rev2 | Layerscape Software Development Kit User Guide | NXP Semiconductors

You can take this info for your board and probably work on your board but for more detailed information for your board contact Solidrun support!

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SD is not visible when booting from eMMC

Re: SD is not visible when booting from eMMC