[PATCH 27/29] bootm: Adjust the parameters of bootm_find_images()

[Simon Glass]

Hi Tom,

On Wed, 15 Nov 2023 at 18:47, Tom Rini <trini at konsulko.com> wrote:
>
> On Wed, Nov 15, 2023 at 06:42:19PM -0700, Simon Glass wrote:
> > Hi Tom,
> >
> > On Wed, 15 Nov 2023 at 15:38, Tom Rini <trini at konsulko.com> wrote:
> > >
> > > On Sat, Nov 11, 2023 at 05:09:12PM -0700, Simon Glass wrote:
> > >
> > > > Rather than passing it all the command-line args, pass in the pieces
> > > > that it needs. These are the image address, the ramdisk address/name
> > > > and the FDT address/name.
> > > >
> > > > Ultimately this will allow usage of this function without being called
> > > > from the command line.
> > >
> > > OK, so this goal is good.
> > >
> > > [snip]
> > > > +             return bootm_find_images(img_addr, argc > 1 ? argv[1] : NULL,
> > > > +                                      argc > 2 ? argv[2] : NULL, 0, 0);
> > >
> > > That we repeat this much harder to read test/if/else three times now is
> > > less good.  Can we find some way to hide the complexity here in the case
> > > where it's coming from a command and so we have argc/argv[] ?
> >
> > I can't really think of one. Ultimately this is coming from the fact
> > that the booti and bootz commands directly call bootm_find_images(). I
> > haven't got far enough to know whether that will still be true in the
> > end, but I hope not.
> >
> > IMO the correct place for the logic above is in the command-processing
> > code, where it decides which arg means what.
> >
> > I could imagine something like:
> >
> > static const char *cmd_get_arg(int argc, char *const argv[], int argnum)
> > {
> >    return argc > argnum ? argv[argnum] : NULL;
> > }
> >
> > but I'm not sure that is an improvement.
>
> I was thinking about this more after I sent this. And I think we might
> indeed want an inline / macro to handle this case more generally as I
> suspect we'll have similar cases where we need argN-or-NULL as we
> refactor other areas of code to split "here is the command" from "here
> is the library functionality" of it. Then we'll have:
> ulong foo = cmd_arg_one(argc, argv);
> ulong bar = cmd_arg_two(argc, argv);
>
> librarycall(foo, bar, ...);

OK I can try something. But note that the one, two terminology becomes
confusing. Is the first argument zero or one? Also we often drop an
argument in a subcommand to allow things to start from 0 again.

It might be better to use first and second, instead?

Regards,
Simon