i.MX Processors中的主题 Re: Where does machine_restart map in the IMX8M kernel sources?

Where does machine_restart map in the IMX8M kernel sources?

john_obendorfer — Sat, 28 Sep 2019 00:39:01 GMT

I'm using the Sumo release on an IMX8MQ. Could any one please point me to the imx8m-specific function called by machine_restart()?

I thought it was mxc_reset() in arch/arm/mach-imx/system.c, but inserting a #error in that function doesn't break the build. That's a pity, because mxc_reset() does exactly what I want: force WDOG1 to fire the system reset signal.

The machine_restart() in arch/arm64/kernel/process.c references two "possible suspects":

1. the pointer arm_pm_restart

2. the function do_kernel_restart()

arm_pm_restart appears to be set in the xen/enlighten.c, but that quickly led to the deferencing of a jump table that I haven't been able to find yet.

On the other hand, do_kernel_restart() appears to walk a list of registered reset handlers, none of which look like they would reset the platform.

Any light that anyone could throw on this would be much appreciated!

Thanks & Regards,

John Obendorfer

Sr Software Engineer

Cognex

Re: Where does machine_restart map in the IMX8M kernel sources?

karangajjar — Tue, 01 Oct 2019 12:59:05 GMT

Hi John Obendorfer,

Can you please let us know which linux kernel version you are using?

Regards,

Karan Gajjar

Re: Where does machine_restart map in the IMX8M kernel sources?

john_obendorfer — Wed, 02 Oct 2019 18:12:52 GMT

Hi Karan,

Sorry, should have put that in the original post.

We're running kernel version 4.14.78 (Sumo) on an IMX8MQ.

Thanks & Regards,

John

Re: Where does machine_restart map in the IMX8M kernel sources?

radhikasomaiya — Fri, 04 Oct 2019 14:52:58 GMT

Hi John Obendorfer,

Are you sure about the version which you are using is Yocto sumo (L4.14.78)? As we are not able to find the mxc_reset() in arch/arm/mach-imx/system.c (In our system's Yocto sumo L4.14.78 build).

Can you let us know exactly what you want to know about reboot? Are you looking for board specific functions for system reset?

Regards,

Radhika Somaiya.