Soft Power Cycling (i.e. shutdown -r now, echo b > /proc/sysrq-trigger)

Is there a way to soft power cycle (meaning 'by software', not meaning 'properly') this board?

I'm using the MontaVIsta Linux 4.0.1
(as found here:  www.ti.com > my.TI Login > Extranets > DaVinci > DM644x > 1.30)

I don't see any Power Management options in the kernel.

The normal method leaves the system hung at halt
shutdown -r now

The forceful method isn't possible
echo 1 > /proc/sys/kernel/sysrq
echo b > /proc/sysrq-trigger

I don't see any Power Management options in the MVL kernel source either.
make menuconfig

 

  • Something happened and the system started to reboot properly. I wasn't able to isolate what change occurred, however, just a few days later in stopped rebooting properly and now instead of hanging at halt / restart as it did before it repeats "BOOTME" every second or so.
    root# shutdown -r now

    Broadcast message from root (console) (Tue Jun  6 00:00:13 1905):

    The system is going down for reboot NOW!
    INIT: Switching toEMAC: TX Complete: Starting queue
    Stopping MontaVista targetRestarting system.
     t BOOTME BOOTME BOOTME BOOTME BOOTME BOOTME BOOTME BOOTME

  • In reply to CoolAJ86:

    The BOOTME prompts indicate that UART boot mode is selected by the boot pins or that the NAND boot mode failed and then the UART boot mode was initiated as the fallback.  I'm guessing the latter since you had obviously booted into Linux correctly before and I'm guessing that was from the NAND itself.  I would start by erasing and rewriting the UBL to the NAND.  Note that the ROM boot loader of the device can search through blocks 1 through 5 of the NAND, so you can place 5 copies of the UBL to help ensure against boot failures like this (I'm assuming that your NAND only had one UBL image and that is what led to the failure you saw).

    Regards, Daniel