[linux-pm] ARM hibernation / suspend-to-disk

[Sebastian Capella]

Quoting tonyho (2014-03-01 23:57:31)
> Now I have try to booting you hibernation_3.13_russMerge branch kernel 
> from uboot(Version 2013-10) in BBB, and I don't know how to build the dtb.
> I have built the uImage using:
> 1. make ARCH=arm CROSS_COMPILE=/media/work/BBB/tools/arm-2010.09/bin/arm-
> none-linux-gnueabi- omap2plus_defconfig && make ARCH=arm 
> CROSS_COMPILE=/media/work/BBB/tools/arm-2010.09/bin/arm-none-linux-gnueabi- 
> uImage LOADADDR=0x80008000
Hi Tony, you'll want to do:
make ARCH=arm CROSS_COMPILE=/media/work/BBB/tools/arm-2010.09/bin/arm- dtbs

This will generate dtb files in arch/arm/boot/dts/

From there, you must take the correct dtb file and include it in your
u-boot.

You'll have to point the bootup to the dtb image you load.

> 2. And I load the uImage using the ext4load from TF card：
> (1)ext4load mmc 0:2 80007f00 /boot/uImage
> (2)and 'iminfo 0x80007f00' hints image is OK.
> (3)The Kernel Command Line is 'init=/linuxrc console=ttyO0,115200n8 
> run_hardware_tests root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait' and 
> I select the 'Always use the default kernel command line'
> and the configuration has been verified in other version linux kernel 
> source code.
> (4)But when I 'bootm 80007f00', it just print the 'Starting kernel ...' 
This is what you expect when it can't find the dtb image, as the dtb is
required to boot.

> and nothing more. And the USERLED0-3 in BBB are off.
> 3. I guess this is caused by I haven't load a dts to memory
> (1)Can you tell me how to build the dtb? Like 'make XXX.dtb/dts'?
> (2)And which dtb should be loaded into memory? What the address should 
> be load for the dtb files?

If you're using beaglebone black, use am335x-boneblack.dtb

The load address is tricky a bit, the answer is it depends on where you
have room.

I'm probably not much help here.

> 4. I use the busybox to be the rootfs, and it test OK. I prepare add a 
> resume command to /sys/power/resume in inittab. Should this work?

For now, probably just get everything booting.  If you can, use an
initrd or initramfs and boot it there.  Once you mount rootfs really on
the SD card, it's too late as you'll corrupt your filesystem.

Sorry about my delayed responses.  I'm in Macao at the Linaro Connect,
but will check emails from time to time.

Thanks,

Sebastian