Linux/PROCESSOR-SDK-AM335X: Not able to boot from emmc

Hi,

Please post what operations you have done for programming the eMMC?

Hi,

We are interfacing 24-bit touch display to beaglebone black. We faced some issues i.e color problem showing like negative images. Later read errata and found problem in red and blue pins, so we make a cape according to errata and now everything is fine, lcd is working properly when booting through micro sd card. And now we flashed eMMC by below attached procedure please find it.

when we power up bbb py pressing s2 button first it's printing 8C's(CCCCCCCC) then booting through sd card card. Later we removed sd card and power up bbb it print a like box [].

Kindly suggest what went wrong.

 

Here are example steps to partition the eMMC and flash kernel and u-boot:

    Assuming the eMMC is /dev/mmcblk1. Format it this way:
    1.01. fdisk /dev/mmcblk1
    1.02. o - this clears the existing partitions
    1.03. p - this lists all partition tables on the card (there should be none)
    1.04. n - create a new partition
    1.05. p - primary partition
    1.06. 1 - partition number
    1.07. 2048 - default value for the first sector
    1.08. +16M - last sector / partition size
    1.09. t - change the partition type (select partition 1)
    1.10. e - change tha partition type to "W95 FAT16 (LBA)"
    1.11. a - set the bootable flag for the selected partition (select partition 1)
    1.12. n - create a new partition
    1.13. p - primary partition
    1.14. 2 - partition number
    1.15. hit Enter to choose the default (next available) value for the first sector
    1.16. hit Enter to choose the default (last) value for the last sector
    1.17. p - this lists all partition tables on the card (there should be two)
    1.18. w - write all the above changes to disk
    
    1.19. umount /dev/mmcblk1p1 - if mounted    
    1.20. mkfs.vfat -F 16 /dev/mmcblk1p1 - format the first partition
    1.21. umount /dev/mmcblk1p2 - if mounted
    1.22. mkfs.ext4 /dev/mmcblk1p2 - format the second partition

    COPY THE {MLO,U-BOOT.IMG,UIMAGE} FILES TO THE FIRST PARTITION:
    2.1. mkdir boot
    2.2. mount /dev/mmcblk1p1 boot
    2.3. cp /media/mmcblk0p1/{MLO,u-boot.img,uImage} boot
    2.4. sync
    2.5. umount boot

    EXTRACT THE ROOT FILE SYSTEM TO THE SECOND PARTITION:
    3.1. mkdir root
    3.2. mount /dev/mmcblk1p2 root
    3.3. tar -xJvf tisdk-rootfs-image-am335x-evm.tar.xz -C root
    3.4. sync
    3.5. umount root

Hi,
We did what you suggest in eMMC partition and formatting by changing type to "W95 FAT32 (LBA)", but this too not booting from eMMC and also tried by making first partition +70M and put a spare area.
Now some times when we are trying to boot from sd card by pressing a button, it is booting from eMMC. And we removed sd card and powered up it's not booting. Please suggest a solution to solve this.

Thank you,
P. Venkata Prasad

Hi,

I'm having trouble understanding the statement below.

Potturu Venkata Prasad said:

Now some times when we are trying to boot from sd card by pressing a button, it is booting from eMMC. And we removed sd card and powered up it's not booting. Please suggest a solution to solve this.

You first said it is not booting from eMMC, but he above statement implies it is. Could you please clarify the problem?

Do you have another Black you can try?

Thanks.

Hi,

when we power up bbb py pressing s2 button first it's printing 8C's(CCCCCCCC) then booting through sd card card. Then we removed sd card (trying to boot from eMMC) and power up bbb it print a like box [].

Later we partitioned and flashed eMMC with the above procedure(attached in previous mail) while making first partition changed type to "W95 FAT32 (LBA)", but still same problem.

Now trying to boot from eMMC its printing [] (like box),and we powered up by pressing s2 button  it is booting from eMMC.

Kindly suggest what's wrong.

Thanks,

P. Venkata prasad.

Hi,
I am tying to boot from sd card, but it is booting from eMMC.
Acoording to the procedure when we press s2 button it should boot from sd card but it is booting from eMMC.

Hi,

You may need to check your Black. When S2 (boot) is pressed, eMMC is not even supposed to be in the boot order. You mentioned above that you are "powering up". The sysboot pins that the boot switch are modifying are only sampled on power up, so a reset won't do the trick. If you are holding down S2 while applying power and going to eMMC, this sounds like a malfunction. You may need to confirm the values of the sysboot pins on the board. Chapter 26 of the TRM covers this in detail if needed.