64GB emmc problem

I’ve developed a custom board that is using a 64GB emmc. Ive read through some earlier posts and followed the steps in the platform adaption and bring up guide. I have two questions I was hoping to get some help with:

  1. Can I specify the rootfs size as 16GiB to flash.sh even though my emmc part is 64GB? When I do this I get an error while using flash.sh that says “Error: No space for primary GPT”

  2. Do I need to change just the BOOTPARTSIZE and EMMCSIZE in the jetson-tk1.conf file? If I use the jetson-tk1.conf file with no changes my board boots but thinks the emmc is bad and the boot sequence drops to u-boot, which makes sense since the boot partitions are not correct.

Any help would be appreciated, thanks for looking


  1. The “-S” parameter to flash.sh is not the actual full size of eMMC…it’s the size of the root partition. You have some of eMMC used by hidden partitions…you can specify “-S” as pretty much any multiple of the sector size within the limits of what is left over after hidden partitions have done their own thing. So far as I know everything is normally 4096 bytes per sector…you can clone the partition table to verify sizes of all partitions and sector size. Note that on a maxed out JTK1 the largest root partition is “-S 14580MiB” out of “16GiB”, so “(16102410241024) - (145801024*1024) = 1891631104 bytes for hidden” (or 1804MiB used by hidden). I have not verified full partition is actually 16GiB there, but if you clone the partition table and add up BytesPerSector times NumSectors it should be near 16GiB. I don’t know if a larger root partition would change this, but I doubt it would…the 1804MiB is likely the same regardless of root partition size. See (this probably covers the partition table):

  2. I don’t know on that one.

Hello, GREGGER31:
EMMC changing is on your own side. Here are only some tips.

  1. EMMCSIZE should be changed according to chip used.
  2. ROOTFSSIZE can be changed as well. BOOTPARTSIZE is not necessary to change. I think you may want to enlarge root-fs size only.
  3. Make sure that EMMC access is OK first (either during flashing, or system-up.)