Re: [Qemu-arm] [Qemu-devel] [PATCH] hw/arm/boot: allow using a command line specified dtb without a kernel

[Peter Maydell]

On 7 October 2016 at 15:09, Stefan Hajnoczi <address@hidden> wrote:
> On Thu, Sep 29, 2016 at 06:58:37PM -0700, Peter Maydell wrote:
>> I think we have two choices:
>> (1) just go ahead and remove the error-check, on the basis that:
>>  * for some boards -dtb is useful even without -kernel
>>  * -dtb might be ignored even with -kernel if the specified
>>    kernel isn't a DTB-aware kernel, but we ignore that
>>  * -dtb is ignored even with -kernel for target archs/boards
>>    which don't support or use DTB, and we don't warn about that
>>  * we don't warn about -kernel being useless for target boards
>>    that don't pay any attention to it
>> (2) add some kind of field to MachineClass indicating whether
>>    the machine can handle dtb files with/without a kernel
>>    (and perhaps also whether the machine supports -kernel at all),
>>    use that to gate the warning messages, and update all the
>>    machines to correctly indicate what they can or can't handle.
>>    This would let us give warning messages when the user asks
>>    for something we're going to ignore (including letting us
>>    fix up some of the cases we don't currently deal with as
>>    enumerated above), but it would be a fair chunk of effort
>>    for a fairly small user-friendliness gain
>>
>> Thinking about it more, I'm inclining towards the simpler
>> option (1). Paolo, do you have an opinion here ?
>
> The error check doesn't seem worth the effort.  It's a convenience
> message to notify users that their configuration is broken but we can't
> detect all the cases where it's broken.  It doesn't seem like a good
> business to be in :).

I agree, so let's apply this patch as-is; added to target-arm.next.

thanks
-- PMM