configs/qemu: add DTB support for ARM Versatile PB

Currently, without this option, you can't boot
ARM Versatile PB with a DTB on QEMU. You get the
following error (using earlyprintk):

Uncompressing Linux... done, booting the kernel.

Error: unrecognized/unsupported device tree compatible list:
[ 'arm,versatile-pb' ]

Available machine support:

ID (hex) NAME
00000183 ARM-Versatile PB
0000025e ARM-Versatile AB

Please check your kernel config and/or bootloader.

Add CONFIG_MACH_VERSATILE_DT to support Versatile platform from device tree

---
 board/qemu/arm-versatile/linux-4.3.config | 1 +
 1 file changed, 1 insertion(+)

index 9a1ae58..99df3a6 100644
@@ -3,6 +3,7 @@ CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
 CONFIG_ARCH_VERSATILE=y
 CONFIG_MACH_VERSATILE_AB=y
+CONFIG_MACH_VERSATILE_DT=y
 CONFIG_PCI=y
 CONFIG_AEABI=y
 CONFIG_USE_OF=y

2.4.9 (Apple Git-60)

Dear Guillaume Delbergue,

Then maybe the board/qemu/arm-versatile/readme.txt file should be updated to make use of the DTB ?

Gustavo ?

Thanks,

Thomas

Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Hi.
Yes, definitely, since we don't default to any form of appended DTB for that defconfig the current instructions will probably result in a non-bootable scenario.
Care to adjust this and send a new patch?
You can look at the vexpress readme.txt (board/qemu/arm-vexpress/readme.txt) on how to adjust/use it, but in theory you already do that unless you changed the kernel output to appended zImage.
Regards.

Hi both,

The platform boots with or without DTB option (-dtb [?]/versatile-pb.dtb) with this patch (tested with QEMU master on Ubuntu 14.04). Of course, I can adjust README. But currently, even with this patch, README is still valid. If you don?t specify dtb, it will use ATAGS and boot.

PS : CONFIG_MACH_VERSATILE_DT ( != ARM_APPENDED_DTB) is not to support appended DTB to zImage. http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/mach-versatile/Kconfig

Regards,

Guillaume Delbergue

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 842 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <http://lists.busybox.net/pipermail/buildroot/attachments/20151125/d0f19d30/attachment.asc>

Dear Guillaume Delbergue,

Finally, a slightly more complete commit implement DT based support for ARM Versatile was pushed. See
https://git.busybox.net/buildroot/commit/?id=5825f1036a7dafcc69de3d84a57876ab0a1585cb

Consequently, I've marked your patch as "Superseded" in our patch tracking system.

Thanks!

Thomas

Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com