From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andy Shevchenko <andy.shevchenko@gmail.com>
Date: Thu, 9 Apr 2020 12:02:05 +0300
Subject: [PATCH v5 12/29] dm: core: Add basic ACPI support
In-Reply-To: <20200408165737.v5.12.Ia5e9ba1f146567b18e9183395484bf04d2e5ba6a@changeid>
References: <20200408225749.171380-1-sjg@chromium.org>
 <20200408165737.v5.12.Ia5e9ba1f146567b18e9183395484bf04d2e5ba6a@changeid>
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On Thu, Apr 9, 2020 at 2:01 AM Simon Glass <sjg@chromium.org> wrote:
>
> ACPI (Advanced Configuration and Power Interface) is a standard for
> specifying information about a platform. It is a little like device
> tree but the bindings are part of the specification and it supports an
> interpreted bytecode language.
>
> Driver model does not use ACPI for U-Boot's configuration, but it is
> convenient to have it support generation of ACPI tables for passing to
> Linux, etc.
>
> As a starting point, add an optional set of ACPI operations to each
> device. Initially only a single operation is available, to obtain the
> ACPI name for the device. More operations are added later.
>
> Enable ACPI for sandbox to ensure build coverage and so that we can add
> tests.

> +int acpi_copy_name(char *out_name, const char *name)
> +{
> +       strncpy(out_name, name, ACPI_NAME_MAX);

_LEN.

The idea as I tried to explain that name can have only 4 bytes at the
end of the page. I dunno what U-Boot does if you access out of the
boundaries to the page which is not mapped to MMU (in OSes it will be
page fault). Does U-Boot map all pages to MMU?

In any case, the code above has this subtle issue. We may live with
it, but since it's a generic kinda function, better to be pedantic
about it.

> +       out_name[ACPI_NAME_LEN] = '\0';
> +
> +       return 0;
> +}

-- 
With Best Regards,
Andy Shevchenko