I am trying to read /dev/mem using the busybox toolset. My goal is to read some registers related to the integrated GPU. By looking at /proc/iomem, it is easy to understand that the gpu device is mapped in physical memory at the address 0x17000000. This is a chunk of my /proc/iomem:
... 15f00000-15ffffff : /host1x/vi@15c10000 16000000-167fffff : /host1x/pva0 16800000-16ffffff : /host1x/pva1 17000000-17ffffff : /gv11b <--- HERE 18000000-18ffffff : /gv11b 30000000-3003ffff : config 30040000-3007ffff : atu_dma 34000000-3403ffff : config 34040000-3407ffff : atu_dma 38000000-3803ffff : config ...
If you try to read with busybox at this address withe the command:
busybox devmem 0x17000000
Then the system hangs for a while and then it reboots.
Repeating this experiment with the Jetson TX2 does not produce any issue.
Do you have any clue about this?