Jetson Nano 4gb, A02 Jetson Nano carrier board, clear JP 4.5 on new SD card 64gb.
https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide/quick_start.html#
Put your Jetson developer kit into Force Recovery Mode (RCM).
1)Ensure that your Jetson Nano developer kit is powered off, and that a 16 GB or larger microSD card is inserted into the module’s microSD card slot.
2)To ensure that the developer kit starts in Force Recovery Mode, place a jumper across the FRC pins of the button header on the carrier board.
•For carrier board revision A02, these are pins 3 and 4 of J40, which is located near the camera header.
3)Place a jumper across J48 to enable use of a DC power adapter.
4)Connect a DC power adapter to J25. The developer kit powers on automatically and enters Force Recovery Mode.
5)Remove the jumper from the FRC pins of the button header.
Recovery mode is not a boot mode in the usual sense. Recovery mode never makes use of the monitor. What recovery mode does is to turn the Jetson into a custom USB device…monitor and other uses have no meaning in this mode. The JetPack/SDK Manager software downloads and installs the “driver package” to your host PC, and it is the driver package which understands recovery mode.
During flash low level access is available due to recovery mode. Once flash completes, then the Jetson reboots, and is no longer in recovery mode. This is when monitors have meaning and is a “true” boot. Without the flash software recovery mode will not change the Jetson in any way.
If flash completes, then the Jetson reboots, and this is when video should show up. If video fails to show up, then it probably means video configuration failed…however, the system might otherwise be fully up and functioning. First boot setup would be needed to add an account for login, so it is problematic if video is failing. Sometimes it is as simple as manually restarting the Jetson for video to show up and to allow first boot account setup.
It doesn’t load at all. Connected via com (usb to tttl) does not write anything. The computer to which is connected via micro USB - win 8.1 via putty console. I read that after booting in the mode, the recovery can be checked with the lsusb command. So how can I check if it won’t load?
I need an ubuntu 18.04 computer on my home pc, download the sdk manager and somehow I can access jetson via micro USB?
Tell me what else I need to do, besides the steps described above, after which I can not access the board in recovery mode.
Recovery mode is required any time you flash directly to the Jetson (there are also prebuilt images available for SD card models of Jetsons which don’t have eMMC). The flash software itself is in the form of a Linux desktop PC binary program, and this cannot run on Windows. So to use the flash software you do need an Ubuntu 18.04 PC (technically 16.04 would work, but this is barely tested in comparison to 18.04; 20.04 can fake being 18.04, but is not guaranteed).
If you are not flashing, and just communicating with serial console, then any o/s will work. The remote PC side could be another Jetson, it could be a Linux PC, it could be Windows, it could be a Mac…they would all work if not in recovery mode and simply communicating over serial console.
Are you trying to flash? If so, then the Linux PC is mandatory. Flash is not a mass storage device being written to…it is a custom hardware device.
Yes, I’m trying to flash. I want to transfer boot to USB SSD. There is a third-party dtb (for imx 477 sensor) that only works from an SD card and a simple fix to extlinux.conf does not work, it still requires an SD card. Another question - eMMC, how to understand if I have it or not? It turns out there are models where there is no removable SD card, but there is a memory chip on the board?
The “development kit” uses a module plus carrier board combination which does not have eMMC, and requires running on micro-SD. You can purchase modules separately, and those modules have eMMC and do not boot from SD. Those modules are considered for use in resale and commercial applications, whereas the dev kit does not have a transferable warranty. For all eMMC models you would need to purchase a third party vendor’s carrier board (the dev kit carrier is not sold separately and is available only with the dev kit module). Most people here are using the dev kit to develop, and the separately purchased module only for commercial production.
If you are trying to boot from a USB SSD, then you should probably start a new thread since this is not related to recovery mode. You would also need to mention if it is a dev kit or separately purchased module.
