Re: [Qemu-devel] [PATCH] hw/core/null-machine: Add the possibility to instantiate a CPU, RAM and kernel

[Peter Maydell]

On 16 January 2017 at 19:44, Eduardo Habkost <address@hidden> wrote:
> On Mon, Jan 16, 2017 at 07:27:21PM +0000, Peter Maydell wrote:
>> On 16 January 2017 at 19:25, Eduardo Habkost <address@hidden> wrote:
>> > On Mon, Jan 16, 2017 at 10:53:07AM -0800, Alistair Francis wrote:
>> >> On Sun, Jan 15, 2017 at 11:59 PM, Thomas Huth <address@hidden> wrote:
>> >> > But I think the users also expect the "-kernel" parameter to be working,
>> >> > so I think we should add the loader code in null-machine.c anyway.
>> >>
>> >> I agree that uses probably expect the '-kernel' option to work as well.
>> >
>> > So, is it possible to write a generic load_kernel() function that
>> > simply reuses the generic-loader code?
>>
>> No, because users expect -kernel to actually load a Linux kernel
>> (meaning with the calling conventions etc the kernel requires),
>> whereas generic-loader is just "load a binary blob and start there".
>
> I don't mean a generic function that works for all machines and
> architectures, but a generic function that is good enough for
> "-machine none". Isn't "load a binary blob and start there"
> exactly what machine_none_load_kernel() in this patch does?

If you just want "load a blob and start it" then we already
have -device loader. Making -kernel have yet another set of
semantics that this time depends on the machine being selected
seems like a bad idea. If -kernel doesn't do what it does
for the other machines of the same architecture then we should
just not accept it.

thanks
-- PMM