12.04.2017 21:10, Brad Mouring пишет:
> Currently, there is not a good way to control script flow based on
> bitwise values. This initially led to NI adding the ability to read
> a specific bit from a port-mapped register to control bootflow.
>
> Here, we add a more generic ability to test the bitwise AND of a
> value available to the grub scripting environment. This obviates the
> need for the inbit command (which is currently OOT).
>
See recent discussion about arithmetic operations. This could also be
if $((a&b)); then
...
fi
I think it is more generic than single specific test.
> Signed-off-by: Brad Mouring <brad.mour...@ni.com>
> ---
> docs/grub.texi | 2 ++
> grub-core/commands/test.c | 10 ++++++++++
> 2 files changed, 12 insertions(+)
>
> diff --git a/docs/grub.texi b/docs/grub.texi
> index 82f6fa4..f28063e 100644
> --- a/docs/grub.texi
> +++ b/docs/grub.texi
> @@ -5019,6 +5019,8 @@ the strings are not equal
> @var{integer1} is less than @var{integer2}
> @item @var{integer1} @code{-ne} @var{integer2}
> @var{integer1} is not equal to @var{integer2}
> +@item @var{integer1} @code{-bwa} @var{integer2}
> +Performs a bitwise AND between @var{integer1} and @var{integer2}
> @item @var{prefix}@var{integer1} @code{-pgt} @var{prefix}@var{integer2}
> @var{integer1} is greater than @var{integer2} after stripping off common
> non-numeric @var{prefix}.
> @item @var{prefix}@var{integer1} @code{-plt} @var{prefix}@var{integer2}
> diff --git a/grub-core/commands/test.c b/grub-core/commands/test.c
> index 5f06642..af4fad7 100644
> --- a/grub-core/commands/test.c
> +++ b/grub-core/commands/test.c
> @@ -290,6 +290,16 @@ test_parse (char **args, int *argn, int argc)
> continue;
> }
>
> + /* GRUB extension: bitwise AND */
> + if (grub_strcmp (args[*argn + 1], "-bwa") == 0)
> + {
> + update_val (grub_strtoul (args[*argn], 0, 0)
> + & grub_strtoul (args[*argn + 2], 0, 0), &ctx);
> + (*argn) += 3;
> + continue;
> + }
> +
> +
> /* -nt and -ot tests. GRUB extension: when doing -?t<bias> bias
> will be added to the first mtime. */
> if (grub_memcmp (args[*argn + 1], "-nt", 3) == 0
>
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