[OE-core] [oe-core] QEMU with ARM Cortex A9 with hard float configuration - Kernel panic

[Bruce Ashfield]

On Thu, Aug 29, 2013 at 3:32 PM,  <rewitt at declaratino.com> wrote:
>
>
>> -------- Original Message --------
>> Subject: Re: [OE-core] [oe-core] QEMU with ARM Cortex A9 with hard float
>> configuration - Kernel panic
>> From: Bruce Ashfield <bruce.ashfield at gmail.com>
>> Date: Thu, August 29, 2013 3:16 pm
>> To: Elvis Dowson <elvis.dowson at gmail.com>
>> Cc: rewitt <rewitt at declaratino.com>,  OpenEmbedded Core Mailing List
>> <openembedded-core at lists.openembedded.org>
>>
>>
>> On Thu, Aug 29, 2013 at 3:01 PM, Elvis Dowson <elvis.dowson at gmail.com> wrote:
>> >
>> > On Aug 29, 2013, at 10:53 PM, <rewitt at declaratino.com> wrote:
>> >
>> >> I actually set up a build to get a vexpress-a15 booting in qemu with
>> >> neon support. However, I didn't use the yocto kernel and just pointed at
>> >> my own defconfig and kernel version 3.10.7. If it would be helpful for
>> >> you, I could put my changes up on github.
>> >>
>> >> The weirdest thing was if I just used the defconfig that is in the
>> >> kernel for vexpress it wouldn't boot, I had to tweak it a bit.
>> >
>> > This is the thing, I was using this as an excuse to learn linux-yocto
>> > kernel. I actually put off using linux-yocto for a while, and tended
>> > to use the official linux kernel, or vendor specific kernels (Xilinx,
>> > TI Arago, Freescale, etc) for actual target devices.
>> >
>> > If you could share your defconfig, I'll try it with the standard
>> > linux kernel.
>>
>> linux-yocto-3.10 is pretty much the standard kernel, unless you want to use
>> the extra features I've merged, it is vanilla.
>>
>> You are going overboard with the definitions. What the build really needs, it'll
>> generate on it's own. If you want to make an official/controlled BSP
>> ... only then
>> do you actually need .scc files, etc.
>>
>> If you add compatbility with the linux-yocto recipe, put a defconfig in the
>> SRC_URI and you are done.
>>
>> Bruce
>
> Ok here is the defconfig I used for a15. I disabled SMP because it was
> annoying me more than helping. I did have to use the dtb generated as
> well, otherwise it wouldn't work.
>
> This is the typical qemu command line I used:
>
> qemu-system-arm -cpu cortex-a15 -M vexpress-a15 -kernel
> images/zImage-qemuarmv7a.bin -append"console=ttyAMA0 mem=512M
> root=/dev/mmcblk0 rw" -m 512 -dtb

Aha. That's the part that has always caused me trouble. Booting directly from
the mmc means I don't have to try and get a platform with sata or other
support that isn't in the real hardware.

> tmp/deploy/images/zImage-vexpress-v2p-ca15_a7.dtb -sd
> tmp/deploy/images/core-image-minimal-qemuarmv7a.ext3 -net nic -net
> user,hostfwd=tcp::2400-:22 -nographic
>
> I also made my own machine configuration so of course the name of the
> rootfilesystem file will be different. As Bruce said, I'm sure this
> could be plumbed in to the yocto infrastructure so that runqemu and the
> various helpers could be used, but I was trying to get an sdk out to
> someone fairly quickly.

:) that sounds familiar, I'll poke around with this over the weekend and see
if it works for me too.

Cheers,

Bruce

>
>> >
>> > I'm doing this to get the process of using Yocto to build a representative
>> > QEMU emulator, and then using LaunchPad and Soyuz locally to
>> > build Ubuntu on a virtual machine, rather than just re-use the official
>> > Ubuntu binary packages. This way, I have more control over the
>> > toolchain, and options, rather than use the existing armel or armhf
>> > machine configurations supplied by Debian/Ubuntu.
>> >
>> > Best regards,
>> >
>> > Elvis Dowson
>> > _______________________________________________
>> > Openembedded-core mailing list
>> > Openembedded-core at lists.openembedded.org
>> > http://lists.openembedded.org/mailman/listinfo/openembedded-core
>>
>>
>>
>> --
>> "Thou shalt not follow the NULL pointer, for chaos and madness await
>> thee at its end"



-- 
"Thou shalt not follow the NULL pointer, for chaos and madness await
thee at its end"