Which partition is the EBT partition?

I’m supposed to re-flash the bootloader to make USB 3 work on the Auvidea J90 carrier board.

The documentation I’ve found says I do this by using flash.sh -t EBT jetson-tx2 {partitionid}

However, I don’t know which of the 17 partitions is the EBT partition. None of them are labeled EBT!

nvidia@tegra-ubuntu:~$ sudo gdisk /dev/mmcblk0
GPT fdisk (gdisk) version 1.0.1

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): p
Disk /dev/mmcblk0: 61071360 sectors, 29.1 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 00000000-0000-0000-0000-000000000000
Partition table holds up to 17 entries
First usable sector is 4097, last usable sector is 61071327
Partitions will be aligned on 1-sector boundaries
Total free space is 1 sectors (512 bytes)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            4097        58724352   28.0 GiB    0700  APP
   2        58724353        58732544   4.0 MiB     0700  mts-bootpack
   3        58732545        58733056   256.0 KiB   0700  cpu-bootloader
   4        58733057        58733568   256.0 KiB   0700  bootloader-dtb
   5        58733569        58739712   3.0 MiB     0700  secure-os
   6        58739713        58739716   2.0 KiB     0700  eks
   7        58739717        58740924   604.0 KiB   0700  bpmp-fw
   8        58740925        58741924   500.0 KiB   0700  bpmp-fw-dtb
   9        58741925        58746020   2.0 MiB     0700  sce-fw
  10        58746021        58758308   6.0 MiB     0700  sc7
  11        58758309        58762404   2.0 MiB     0700  FBNAME
  12        58762405        59024548   128.0 MiB   0700  BMP
  13        59024549        59090084   32.0 MiB    0700  SOS
  14        59090085        59221156   64.0 MiB    0700  kernel
  15        59221157        59221668   256.0 KiB   0700  kernel-dtb
  16        59221669        59745956   256.0 MiB   0700  CAC
  17        59745957        61071326   647.2 MiB   0700  UDA

Which of these is the bootloader? Do I still use flash.sh -t EBT to flash the bootloader? Does it matter that “make” in the bootloader directory fails, complaining there is no “.config” created? (Even though I can make the kernel and modules?)

(And, honestly, WTH? Why is there more than a “boot” partition and a “file system” partition? What are the all for? What document am I missing that explains them all?)

A partial answer is that the partition scheme has inherited from prior tegra devices and that the flash software wasn’t always dedicated to Jetsons. Before R19 I think fastboot was it. Fastboot does not read a partition via any file system, e.g., it can’t read ext2, so it had dedicated partitions for a number of things (reading a raw partition instead of a file system simplifies requirements for the boot loader even if it makes life more difficult for the developer). One is the kernel (the partition is still there even if not used), apparently also various configuration items, perhaps device tree and command line environment as part of that list.

I don’t know if there is an equivalent to this for t186, but TX1 has an expanded explanation of part of this here:

It might be interesting to clone anything unknown and see if the checksum matches the boot image binary.

I would also not mind seeing a document equivalent to the one in the above URL for the t186 since the Denver core boot is new.

All of which still doesn’t tell me how I properly re-flash the bootloader.
The README from Auvidea just says “there are plenty of tutorials on the internet for how to do this,” without linking to any one that’s known to work.

hello snarky,

EBT partition name was CBoot partition for TX1, in TX2 we’re using “cpu-bootloader”
for TX2, bootloader included MB1, MB2, TBoot, CBoot, and UBoot.
you could refer to NVIDIA Tegra Linux Driver Package 28.1 Release Development Guide,
checking Boot Loader and U-Boot Customization session for more details.