Re: [PATCH 0/7] build: replace ninjatool with ninja

[Mark Cave-Ayland]

On 15/10/2020 22:41, Paolo Bonzini wrote:

> Il gio 15 ott 2020, 20:49 Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk 
> <mailto:mark.cave-ayland@ilande.co.uk>> ha scritto:
>
>     Is there any reason why
>     https://lists.gnu.org/archive/html/qemu-devel/2020-09/msg06997.html
>     <https://lists.gnu.org/archive/html/qemu-devel/2020-09/msg06997.html> still 
> can't be
>     merged?
>
>
> Because it's not the right approach. There is no reason why building firmware cannot 
> be done with cross compilers, so moving those directories to Meson (not because Meson 
> can't handle them; more specifically, the issue is tying the firmware build to the 
> QEMU build system) is going in the wrong direction.
>
> The "Canadian cross" scenario, where you build on Linux a mingw GCC but the compiler 
> is s390, is not even enough to describe the complexity in the case of QEMU, because 
> there are multiple firmware for different machines.
>
> However we already have all the infrastructure to do such builds, we just don't use 
> it for the firmware. So, instead of the patch you recalled above, the tests/tcg 
> machinery should be extended into something that can be reused for firmware. As an 
> aside, orchestrating this multi-compiler part of the build is what the Makefiles will 
> keep on handling for the foreseeable future. As an aside to the aside, tests/tcg is 
> more than underdocumented and I forget everything about it 5 minutes after looking at it.
>
> This is not something that I will be able to work on anytime soon. But still I don't 
> think that going in the wrong direction is a good idea, even if temporarily.

That's a shame, although I do appreciate the huge amount of time and effort that 
you've put into this release in order to get the Meson build up and running, and so 
why taking on another large task is going to be lower down the list :)

At the moment OpenBIOS doesn't have a docker image capable of building the required 
binaries: I did experiment with trying to use the QEMU docker images for openbios-ppc 
but whilst the binary built successfully, it did not run compared to my hand-rolled 
compilers. So there's still some debugging to be done there...


ATB,

Mark.