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AM3352 ROM 22.03 not booting Micron MTFC16GAKAECN-AIT eMMC

Other Parts Discussed in Thread: AM3352, CSD

Here are the thinks I analysed already:

  • possibly we have an issue with AM3352 ROM code and TAAC
  • TAAC value is much higher for the automotive eMMC 0x4 –> 0x7 , this is 1000 times slower
  • Mircon mentioned this is worst case but we do not know if the TI ROM driver cares about TAAC register
  • NFS booting and linux driver handling of eMMC is with out any issues
  • forcing user area as boot partition in eCSD does not help 
  • programming and reading back of 2GB image has same CRC

best regards, 

Boris

  • What is the size of this eMMC and to which processor pins is it connected?
  • 16GB default MLC mode. Nothing changed in MMC registers. everything default. AM3352 Pins MMC0 interface with D[0-7] connected. DTS is supporting only D[0-3] at the moment . And our yocto wic generated image is booting on same PCB with Kingston and also non automotive Micron eMMC. So must be ROM or boot config partition register of eMMC. But the 7.4.63 PARTITION_CONFIG [179] I forced to user area with out success.
  • MMC0 booting is restricted to eMMC < 4GB. It may boot from larger eMMCs, but this is not guaranteed. See section 26.1.7.5.2 from the AM335x TRM Rev. N.
  • Why its not guaranteed, working Micron and Kingston is also 16GB. The CSD size is for all device greater than 4GB ?
    Strange. Looks more like a timing parameter that is proportional to size ?
    Can you acknowledge if we can use a 8GB MLC in 4GB pSLC mode, because this should be fine in CSD (shows < 4GB usable)
    And smaller 4GB you can only order 2GB ! Some newer Revisions of BBB with 4GB Micron eMMC are shipped in pSLC 2GB, was this out of the same reason ?
  • The eMMC on BBB is on mmc1, not mmc0.

    Steve K.

  • BBB has the eMMC connected to MMC1, so there is no issue there. As for your first question, this post by Steve Kipisz explains the difference: e2e.ti.com/.../1827026

  • 26.1.7.5.2 System Interconnection
    
    Each interface has booting restrictions on which type of memory it supports:
    
    • MMC0 supports booting from the MMC/SD card cage and also supports booting from eMMC/eSD/managed NAND memory devices with less than 4GB capacity.

    
    

    In my opinion the statement "also" eMMC with less than 4GB is different from the new forum statement "only" below 4GB with exceptions for more than 4GB that are diffuse !

    If eMMC 4.41 compliant devices are able to boot with more than 4GB then there must be a difference to 5.0. If this is not the case the ROM is not 4.41 compliant and this should be added to the errata.

    Is it possible to mention what exception of  eMMC 5.0 compliant device between eMMC 4.41 is the root cause of ROM boot refusal 

    In eMMC Spec 5.0 there is a delta list between the different standards in: Annex B (informative) Changes between system specification versions

    And i am still curious  if it is possible to boot from a 8GB MLC in 4GB pseudo SLC mode. In CSD register your ROM could not detect because the size is faked to 4GB.

    Best regards,

    Boris

  • I will ask the factory team to provide further comments.