On Mon, Feb 22, 2021 at 11:03 AM Pavel Machek <[email protected]> wrote: > > On Tue 2020-11-10 21:27:46, Matteo Croce wrote: > > From: Matteo Croce <[email protected]> > > > > The kernel cmdline reboot= option offers some sort of control > > on how the reboot is issued. > > Add handles in sysfs to allow setting these reboot options, so they > > can be changed when the system is booted, other than at boot time. > > We already have a reboot syscall, do we need sysfs interface, too? > > > > +What: /sys/kernel/reboot/mode > > +Date: November 2020 > > +KernelVersion: 5.11 > > +Contact: Matteo Croce <[email protected]> > > +Description: Reboot mode. Valid values are: cold warm hard soft gpio > > > > +What: /sys/kernel/reboot/type > > +Date: November 2020 > > +KernelVersion: 5.11 > > +Contact: Matteo Croce <[email protected]> > > +Description: Reboot type. Valid values are: bios acpi kbd triple efi pci > > what is difference between mode and type? What is difference between > cold and hard for example? WTF is gpio? > > > +What: /sys/kernel/reboot/cpu > > +Date: November 2020 > > +KernelVersion: 5.11 > > +Contact: Matteo Croce <[email protected]> > > +Description: CPU number to use to reboot. > > Why should user care about this? >
Mode is the reboot mode (soft, warm, cold, gpio), and type is an x86 specific type, (bios, acpi, uefi, etc.). I never used GPIO reboot but it's used by some ARM devices. I didn't invent anything from scratch, I just transposed the settings available from the kernel command line (see Documentation/admin-guide/kernel-parameters.txt) to sysfs. Everithing was already tunable before, like the CPU used during reboot. -- per aspera ad upstream
