[fedora-arm] f21 + qemu requires manually passing a dtb?

[Cole Robinson]

On 11/19/2014 03:47 PM, Paul Whalen wrote:
>
>
> ----- Original Message -----
>> On 11/19/2014 10:23 AM, Peter Robinson wrote:
>>>>>>> Just trying the F21 beta (and
>>>>>>> Fedora-Minimal-armhfp-21-20141117-sda.raw)
>>>>>>> under
>>>>>>> qemu. Seems like these versions both require explicitly passing in a
>>>>>>> dtb
>>>>>>> to
>>>>>>> qemu to actually boot. Well, maybe it's booting and I'm just not
>>>>>>> getting
>>>>>>> any
>>>>>>> serial output, can't really tell.
>>>>>>>
>>>>>>> Passing a dtb to qemu wasn't required for the F20 GA release at least,
>>>>>>> and
>>>>>>> still isn't required with F21 qemu-system-arm, so presumably it's not a
>>>>>>> qemu
>>>>>>> regression.
>>>>>
>>>>>
>>>>> Fedora 21 requires the use of a dtb to boot the multiplatform kernel.
>>>>> This
>>>>> changed
>>>>> around the 3.16 RC's (iirc).
>>>>>
>>>>>>>
>>>>>>> Having to pass a dtb is kind of a pain for management tools, it's
>>>>>>> another
>>>>>>> file
>>>>>>> that needs to handled. And the docs say it shouldn't be required:
>>>>>>>
>>>>>>> https://fedoraproject.org/wiki/Architectures/ARM/F21/Installation#For_Versatile_Express_Emulation_with_QEMU
>>>>>
>>>>>
>>>>> Thanks, I will adjust the page.
>>>>>
>>>>
>>>> Medium/long term we should consider changing the docs to recommend using
>>>> qemu-system-arm -M virt, since that's where all the virt improvements are
>>>> generally going to take place, and it doesn't require an explicit dtb
>>>> (since
>>>> it generates ones behind the scene). That will also be the virt machine
>>>> type
>>>> used for aarch64, so it will be nice to have parity there.
>
> What command should be used? When I add in -M virt and do not include a dtb, I
> dont get any output on the serial console (a9, a15) using qemu-system-arm-2.1.2-6.fc21.x86_64.
>

I did this with virt-install:

sudo virt-install --name f21-arm-machvirt --ram 1024 --arch armv7l --disk 
Fedora-Minimal-armhfp-21-20141117-sda.raw --import --boot 
kernel=vmlinuz-3.17.2-300.fc21.armv7hl,initrd=initramfs-3.17.2-300.fc21.armv7hl.img,kernel_args="console=ttyAMA0 
rw root=/dev/vda3 rootwait"

But looking at the libvirt generated qemu command line is probably more 
confusing than enlightening. What command line did you use? Maybe I can spot 
the problem

- Cole