[Jetson Nano SPI Issue] TX Data Present, RX Always Zero – Post-Reflash Debugging Steps & Observations

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
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14

Hello again @KevinFFF, yes I am using Jetson Nano with SD module.

I’ve managed to study VirtualBox so that i can locally use the flash script without having to etch an image onto the sd card via balena etcher.

from here, I went ahead and redid these steps

  1. I went to the site and downloaded the BSP and sample root filesystem on my laptop
  2. extracted bsp (tar xpf Jetson-210_Linux_R32.7.6_aarch64.tbz2)
  3. extracted the root file system (sudo tar xpf ~/jetson_nano_image/Tegra_Linux_Sample-Root-Filesystem_R32.7.6_aarch64.tbz2)

which enables me to follow the steps again in

Jetson Nano SPI Bus Not Working - #10 by KevinFFF

specifically,

Check flash log to know which dtb you are using (in my case, is the a00
Method 2 - Remove from decompiled dtb
2-2-2-1 Find you dtb in Linux_for_Tegra/kernel/dtb/tegra210-p3448-0000-p3449-0000-a00.dtb

2-2-2-2 Dissemble the dtb to dts
dtc -I dtb -O dts -o temp.dts tegra210-p3448-0000-p3449-0000-a00.dtb

2-2-2-3 Modify the following line

  •    gpio-input = <0xd8 0xc 0xd 0xe 0xf 0xe8 0x26 0x95 0x5 0xbc 0xbd 0xbe 0xc1 0xc2 0xa8 0xc8 0xca 0x4d 0x4e 0x4c 0x4f 0x32 0x33 0x10 0x11 0x12 0x13 0x14 0x3a 0x3d 0x3e 0x41 0xe4>;

  •    gpio-input = <0xd8 0x26 0x95 0x5 0xbc 0xbd 0xbe 0xc1 0xc2 0xa8 0xc8 0xca 0x4d 0x4e 0x4c 0x4f 0x32 0x33 0x3a 0x3d 0x3e 0x41 0xe4>;

2-2-2-4 Assemble the dts back to dtb
dtc -I dts -O dtb -o tegra210-p3448-0000-p3449-0000-b00.dtb temp.dts

2-2-2-5 Flash the board

In the flashing process, I followed this forum’s (How to Put NVIDIA Jetson NANO B01 in Force Recovery Mode? - #2 by andres.campos) instruction for putting the nano into force recovery mode

So, I tried flashing and I was stuck in the line

[   0.0826 ] Boot Rom communication
[   0.1065 ] tegrarcm --chip 0x21 0 --rcm rcm_list_signed.xml --skipuid

I did verify that VirtualBox connected to my nano and I double checked using $ lsusb which printed

Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 003: ID 80ee:0021 VirtualBox USB Tablet
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 0955:7f21 NVIDIA Corp. APX

despite proving connection by the software and the cli, i seem to get stuck in that line when flashing.