Re: [Qemu-devel] [PATCH for-2.12 3/7] tests/boot-serial-test: Add support for the mcf5208evb board

[Paolo Bonzini]

On 30/11/2017 13:51, Peter Maydell wrote:
> On 30 November 2017 at 12:40, Paolo Bonzini <address@hidden> wrote:
>> On 30/11/2017 13:14, Peter Maydell wrote:
>>> On 30 November 2017 at 08:53, Thomas Huth <address@hidden> wrote:
>>>> +static const uint8_t kernel_mcf5208[] = {
>>>> +    0x41, 0xf9, 0xfc, 0x06, 0x00, 0x00,     /* lea 0xfc060000,%a0 */
>>>> +    0x10, 0x3c, 0x00, 0x54,                 /* move.b #'T',%d0 */
>>>> +    0x11, 0x7c, 0x00, 0x04, 0x00, 0x08,     /* move.b #4,8(%a0)     
>>>> Enable TX */
>>>> +    0x11, 0x40, 0x00, 0x0c,                 /* move.b %d0,12(%a0)   Print 
>>>> 'T' */
>>>> +    0x60, 0xfa                              /* bra.s  loop */
>>>> +};
>>>
>>> This approach doesn't seem to be scalable to me -- are we
>>> really going to have 50 or more fragments of hand-coded hex in
>>> this file to cover the various board models?
>>>
>>> I'd much rather see us have a framework for being able
>>> to build test blobs from source using a cross compiler
>>> setup (and docker or similar so anybody can rebuild
>>> the test blobs). That will be much easier to maintain
>>> and easier to extend to having tests that test other
>>> parts of the board or other aspects of TCG emulation.
>>
>> It seems a bit overkill, as these snippets are ~16 bytes long.
> 
> They're 16 bytes long because that's about the limit of
> what you can do with this approach. The consequence is that
> they barely test anything at all.

Certainly they are an awful test for boards, but they are a great smoke
test for TCG changes that require modifications in all target/
subdirectories.

The infrastructure you want for integration tests is already provided by
kvm-unit-tests, which satisfies at least bullets 2-4 from your list
below (the first is unclear to me).

Thanks,

Paolo

> A more sensible framework
> would allow:
>  * better testing of TCG instructions more generally
>  * writing your test cases in C
>  * more interesting board dependent tests
>  * "integration test" setups like 'boot entire kernel'
>  * etc
> 
> thanks
> -- PMM
>