Remote reboot into recovery mode?

Autonomous Machines Jetson & Embedded Systems Jetson TK1
#1

whether it is possible to remote reboot into recovery mode from running os?

edit:

i found way by serial console

Tegra124 (Jetson TK1)
enterrcm

Entering RCM...

But is any way add this to u-boot menu?

#2

I doubt this could be done (though it might). Prior to a boot loader menu it has to set up registers at a very low level, including things like clock timings, tri-state logic, voltage-sensitive board settings, etc. Though I could be wrong I believe the recovery mode button changes registers before the boot loader even begins and the register states may not be compatible. As for security, be glad it doesn’t do this :P

On the other hand, you might find someone from nVidia that can answer this without doubt.

#3

http://http.download.nvidia.com/tegra-public-appnotes/tegra-boot-flow.html

“If Tegra PMC register scratch0 bit 2 is set at power-up, recovery mode will be entered. This register bit is not cleared when Tegra resets, so any software may set this bit, then reboot, to request recovery mode.”

https://github.com/NVIDIA/tegrarcm

That one doesn’t list T124 though.

#4

To answer Santyago’s initial question, the L4T kernel accepts “forced-recovery” as a command to the reboot syscall, e.g.:

syscall(SYS_reboot, 
            LINUX_REBOOT_MAGIC1, 
        LINUX_REBOOT_MAGIC2, 
        LINUX_REBOOT_CMD_RESTART2, "forced-recovery");