Re: [PATCH v4 1/3] binman: Allow selecting default FIT configuration

Hi Alper,

On Tue, 8 Sep 2020 at 11:33, Alper Nebi Yasak alpernebiyasak@gmail.com wrote:

On 06/09/2020 19:39, Simon Glass wrote:

...

Add a new entry argument to the fit entry which allows selection of the default configuration to use. This is the 'default' property in the 'configurations' node.

Update the Makefile to pass in the value of DEVICE_TREE or CONFIG_DEFAULT_DEVICE_TREE to provide this information.

Signed-off-by: Simon Glass sjg@chromium.org Suggested-by: Michal Simek michal.simek@xilinx.com

---

Changes in v4:

• Add more documentation for DEFAULT-SEQ

I might be too late to say this but the SEQ thing looks ugly to me. Maybe there could be some generic control-flow-like nodes that could generate and insert things in their own place. If it makes sense, I'm imagining something like:

fit {
    images {
        __for__ {
            for,variable = "name";
            for,in-args = "of-list";

            fdt-#name {
                description = "fdt-$name.dtb";
                type = "flat_dt";
                compression = "none";
            };
        };
    };

    configurations {
        __for__ {
            for,variable = "name"
            for,in-args = "of-list";

            __if__ {
                if,arg-equals = "default-dt", "$name";
                default = "config-#name";
            };

            config-#name {
                description = "conf-$name.dtb";
                fdt = "fdt-#name";
            };
        };
    };
};

I certainly like the flexibility of this and I fiddled with something similar (without the __if__ as I didn't have 'default support) before going with a hard-coded approach. I agree what I have is ugly and I'm pleased to get some feedback.

I think we could use _for instead of __for__.

For $name I avoided that because it only works if there is a non-character afterwards, e.g. $namex is ambiguous. I briefly played with ${name} and {name} but ended up with the ugly capitals.

The biggest question in my mind is whether we want our device-tree templates to be turing-complete. It seems nice but I feel that what you have above is much harder to understand and get right.

Regards, Simon