Getting "devmem: mmap: Operation not permitted" when attempting to test PCIe
Hi. I have two Jetson AGX Xaviers. I am attempting to test PCIe using these two Xaviers using the following documentation from NVIDIA:
https://docs.nvidia.com/jetson/archives/r34.1/DeveloperGuide/text/SD/Communications/JetsonAgxXavierPcieEndpointMode.html
As mentioned in the above documentation, I flash one Xavier as root port, and the other as end point. I follow the instructions, and am able to follow them till the point where I get the end point’s BAR address. My end point BAR address was:
BAR0 RAM phys: 0x108338000
After that, the next step mentioned in the documentation is to read the end point memory using the following command:
Based on this, I entered the following command:busybox devmem 0x108338000
However, when I run this command on the end point, I get the following message:
devmem: mmap: Operation not permitted.
Memory write using the busybox devmem command also gives same error message.
( For reference, memory write command used was:busybox devmem 0x108338000 32 0xfa950000
)
How do I resolve this issue? I am running Jetpack 5.1 on both the root port and the end point.