Re: [PATCH v3 7/7] of: Add KUnit test to confirm DTB is loaded

[Stephen Boyd]

Quoting Rob Herring (2024-02-13 09:52:00)
> On Fri, Feb 9, 2024 at 8:59 PM Stephen Boyd <sboyd@xxxxxxxxxx> wrote:
> >
> > ---8<---
> > diff --git a/init/main.c b/init/main.c
> > index e24b0780fdff..02f5cf8be6c1 100644
> > --- a/init/main.c
> > +++ b/init/main.c
> > @@ -97,6 +97,8 @@
> >  #include <linux/jump_label.h>
> >  #include <linux/kcsan.h>
> >  #include <linux/init_syscalls.h>
> > +#include <linux/of.h>
> > +#include <linux/of_fdt.h>
> >  #include <linux/stackdepot.h>
> >  #include <linux/randomize_kstack.h>
> >  #include <net/net_namespace.h>
> > @@ -895,6 +897,8 @@ void start_kernel(void)
> >         pr_notice("%s", linux_banner);
> >         early_security_init();
> >         setup_arch(&command_line);
> > +       if (!of_root)
> 
> of_root is another thing I'd like to remove direct access to. That
> check could be inside unflatten_device_tree().

Ok.

> 
> > +               unflatten_device_tree();
> 
> That's back to what Frank had essentially and I wanted to avoid.

Alright, fair enough.

> 
> I think I'd just disable the tests on the above arches and let them
> opt-in. I could be convinced otherwise though.
> 

Kunit folks would prefer to skip tests when dependencies aren't
satisfied. The OF_UNITTEST config already depends on !SPARC so perhaps
it's simplest to have tests skip if OF_EARLY_FLATREE=n. Then
OF_EARLY_FLATREE can be def_bool OF && !(SPARC || M68K || other arches).
The OF_UNITTEST config can depend on OF_EARLY_FLATREE instead of select
it then. This way new supporting architectures can remove themselves
from the def_bool line when they start calling unflatten_device_tree().