• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 98 subscribers
  • Views 247 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TDA4VM: Unable to select an MMC device from U-Boot when booting from flash

Marko Gostovic
Prodigy 190 points

Part Number: TDA4VM

Hi, everyone,

I am attempting to boot the Linux OS in such a way that the boot files are stored in the internal flash memory, while the root file system is stored on a micro SD card.

After some inspection, it has been attempted to print some information about the inserted micro SD card from U-Boot, using the "mmc info" command. When, for example, an SD card is used both for the boot files and the root file system, the "mmc list" command prints the following output:

=> mmc list
sdhci@4f80000: 0
sdhci@4fb0000: 1 (SD)
sdhci@4f98000: 2

After selecting the SD card by the "mmc dev 1" command, there is a message printed, which indicates that the operation is successful and that the "mmc1" is the current device. Also the "mmc info" command succeeds.

When the internal flash is used instead of the micro SD card for storing the boot files, the "mmc list" command prints the following output (the SD card is still inside the reader):

=> mmc list
sdhci@4f80000: 0
sdhci@4fb0000: 1
sdhci@4f98000: 2

There is no "(SD)" printed in the second line of the output.

When attempting to select the device number 1 by the "mmc dev 1" command, the operation fails with the following message:

Card did not respond to voltage select! : -110

Is it possible to assemble such a constellation, so that the boot files are inside the internal flash and the root file system is located on a micro SD card?

If such a case is supported, which settings would be needed to support this option?

  • 0
    TI__Guru 71165 points

    Hi Marko,

    Marko Gostovic said:

    Card did not respond to voltage select! : -110

    While using second combination can you probe the clk line and see if clock is coming.

    Seems some issue with clock.

    Also check you pinmux settings in uboot used for mmcsd.

    Marko Gostovic said:

    Is it possible to assemble such a constellation, so that the boot files are inside the internal flash and the root file system is located on a micro SD card?

    Yes it is possible to have a boot binary in the emmc and root file system in the sd card , You just need to copy bot images to the emmc and in uboot you need to mention that rootfs  need to be taken from sd card by changing env variable(args_mmc)

    Regarsds
    Diwakar