DreamPlug / GuruPlug support in 3.12-rc

[Jason Cooper]

Robert,

I add the other kirkwood/Marvell maintainers to the Cc:

On Sun, Oct 20, 2013 at 01:08:34PM +0100, robert wrote:
> I have an 'older' DreamPlug, that is - effectively - a GuruPlug inside:

Yes, all Dreamplugs are essentially a Guruplug without the heat problems
:)  The big difference is that the Guruplugs have NAND flash and the
Dreamplugs have 2MB NOR flash (for u-boot and environment).  DP uses the
micro SD card for rootfs.

> # cat /proc/cpuinfo
> processor       : 0
> model name      : Feroceon 88FR131 rev 1 (v5l)
> BogoMIPS        : 1191.11
> Features        : swp half thumb fastmult edsp
> CPU implementer : 0x56
> CPU architecture: 5TE
> CPU variant     : 0x2
> CPU part        : 0x131
> CPU revision    : 1
> Hardware        : Marvell GuruPlug Reference Board
> Revision        : 0000
> Serial          : 0000000000000000
> 
> UBoot:
> Marvell-DreamPlug
> SoC:   Kirkwood 88F6281_A0
> 
> I have managed to get kernels up to 3.11.6 to compile and install OK,
> with the 'device tree' option, by selecting 'Marvel GuruPlug reference
> board' and 'Marvel GuruPlug reference board (flattened device tree)',
> but none of the available options on 3.12-rc seem to work..    I have
> tried selecting all the 'Marvell Kirkwood' options, and the 'Marvell
> SOC' options, and none of these produces a bootable kernel.

Yes, the DT conversion has progressed far enough that we don't need
much, if any, code (board-dreamplug.c) for individual boards.  So the
Kconfig options for individual boards have been removed.  When you
select "Marvell Kirkwood Flattened Device Tree", it will build a kernel
bootable on any of the kirkwood boards.  After the zImage is built, you
need to run 'make dtbs' and it will build all of the available kirkwood
dtb files for you.

> As a test, I temporarily deselected 'Embedded system', and got the
> following at boot:
> Uncompressing Linux... done, booting the kernel.
> Error: unrecognized/unsupported machine ID (r1 = 0x00000a63).
> Available machine support:
> ID (hex)        NAME
> 00000b44        Marvell OpenRD Ultimate Board
> 00000939        Marvell OpenRD Client Board
> 00000915        Marvell OpenRD Base Board
> 00000691        Marvell RD-88F6192-NAS Development Board
> 00000692        Marvell RD-88F6281 Reference Board

Unless you plan on booting this kernel on any of these boards, you can
go ahead and disable building the above legacy board files.

> ffffffff        Marvell Kirkwood (Flattened Device Tree)
> Please check your kernel config and/or bootloader.

You need to enable CONFIG_ARM_APPENDED_DTB and then append the
appropriate dtb:

$ cp arch/arm/boot/zImage /tmp/
$ cat arch/arm/boot/dts/kirkwood-dreamplug.dtb >>/tmp/zImage
$ mkimage ... -d /tmp/zImage /tmp/uImage

Alternatively, you could upgrade u-boot to mainline which has supported
both the dreamplug and DT booting for a _long_ time now.  A lot of folks
are uncomfortable with that, though.  Which is why we added
CONFIG_ARM_APPENDED_DTB as a temporary work around.

> 0a63(hex) is 2659(dec), which is, in ~/arch/arm/tools/mach-types:
> guruplug        MACH_GURUPLUG        GURUPLUG        2659

Yes, that was a bad design decision on the part of Globalscale, nothing
we can do about it. :(

> I appreciate that ARM support in 3.12-rc is still a work-in-progress,
> but would like to know if this support will be included soon..   I have
> - as usual - tried to find some clues online, but haven't found
> anything, so far...

Asking here is the right thing to do.  Let us know how the above works
out for you.

hth,

Jason.