I successfully boot the 3.8.13 kernel with some modifications in .config
(namely, I am disabling all the ethernet drivers like cpsw). However, when
I try to boot the 3.8.13-rt9 kernel (with preempt_rt patch), it hangs up
after "Uncompressing Linux... done, booting the kernel."
- all four LEDS (D2 to D5) are lit up immediately after and are kept lit
until the system restarts after a minute or so
- there is no output on the serial console
- I don't think that there is a problem with specifying the wrong tty port
in bootargs in the uEnv.txt since I kept the same settings as for regular
3.8.13 kernel
- I am booting the zImage from the rfs partition of the SD card, u-boot is
in the boot partition of the sd card; the actual rfs used is in the eMMC -
this configuration works with regular 3.8.13 kernel
My main question is how to get any debug messages when the kernel is stuck
so early. I set CONFIG_DEBUG_LL=y, CONFIG_DEBUG_LL_UART_NONE=n,
CONFIG_EARLYPRINTK=y etc., but there is still no output and no log to
kern.log
Did anyone else experience the situation when all LEDs lit up during boot?
It seems something goes wrong very early in the boot process, like some
uboot parameters are set wrong. But I did not change anything compared to
the setup I use for booting the 3.8.13 kernel without preempt_rt. This is
my uEnv.txt, for example:
#kernel_file=/boot/vmlinuz-3.8.13/zImage
> #dtb_file=/boot/dtbs-3.8.13/am335x-boneblack.dtb
> kernel_file=/boot/vmlinuz-3.8.13-rt9/zImage
> dtb_file=/boot/dtbs-3.8.13-rt9/am335x-boneblack.dtb
>
> loadzimage=load mmc 0:2 ${loadaddr} ${kernel_file}
> loadfdt=load mmc 0:2 ${fdtaddr} ${dtb_file}
>
> console=ttyO0,115200n8
> mmcroot=/dev/mmcblk1p2 ro fixrtc
> mmcrootfstype=ext4 rootwait
>
> mmcargs=setenv bootargs root=${mmcroot} rootfstype=${mmcrootfstype}
> console=${console}
>
> #zImage:
> uenvcmd=run loadzimage; run loadfdt; run mmcargs; bootz ${loadaddr} -
> ${fdtaddr}
>
Could the problem be that I am using the kernel from here:
https://github.com/beagleboard/kernel/tree/3.8-rt
Perhaps someone could suggest a more recently tested version with
preempt_rt patch? Perhaps something from the RobertCNelson repo:
https://github.com/beagleboard/linux/tree/3.8
--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/beagleboard/6525c96b-bc7e-4e56-8b91-c0425060fe35%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
