From: Jiaxun Yang <jiaxun.yang@flygoat.com>
To: YunQiang Su <wzssyqa@gmail.com>,
"Maciej W. Rozycki" <macro@linux-mips.org>
Cc: linux-mips <linux-mips@vger.kernel.org>,
Fangrui Song <maskray@google.com>,
Nathan Chancellor <natechancellor@gmail.com>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] MIPS: malta: Set load address for 32bit kernel correctly
Date: Mon, 06 Apr 2020 19:10:58 +0800 [thread overview]
Message-ID: <079F408B-9C44-4317-8DD3-7A1896564960@flygoat.com> (raw)
In-Reply-To: <CAKcpw6U=VW+h4sU1fzrsqXU9z-zVfcFsENKHgAD4paqtndip2w@mail.gmail.com>
于 2020年4月6日 GMT+08:00 下午6:57:18, YunQiang Su <wzssyqa@gmail.com> 写到:
>Maciej W. Rozycki <macro@linux-mips.org> 于2020年4月6日周一 上午1:23写道:
>>
>> On Mon, 6 Apr 2020, Jiaxun Yang wrote:
>>
>> > > Given the description above I think it should be done uniformly
>and
>> > >automatically across all platforms by trimming the address
>supplied
>> > >with
>> > >$(load-y) to low 8 digits in a single place, that is at the place
>where
>> > >
>> > >the variable is consumed. This will reduce clutter across
>Makefile
>> > >fragments, avoid inconsistencies and extra work to handle
>individual
>> > >platforms as the problem is triggered over and over again, and
>limit
>> > >the
>> > >risk of mistakes.
>> >
>> > I was intended to do like this but failed to find a proper way.
>> >
>> > Makefile isn't designed for any kind of calculation.
>> > And shell variables are 64-bit signed so it can't hold such a huge
>variable.
>> >
>> > Just wish somebody can give me a way to do like:
>> >
>> > ifndef CONFIG_64BIT
>> > load-y = $(load-y) & 0xffffffff
>> > endif
>>
>> Use the usual shell tools like `sed', `cut', `awk', or whatever we
>use in
>
>perl may be the easiest to use tool here.
>
>ifndef CONFIG_64BIT
> load-y := $(shell $(PERL) -e 'print $(load-y) & 0xffffffff')
>endif
>
>Note that it is `:=' instead of '='.
It seems like perl is not one of kernel's build dependencies.[1]
I'm comsidering a alternative solution,
write a small hostprog in C to deal with that.
Thanks.
[1]: https://www.kernel.org/doc/html/v5.6/process/changes.html
>
>> the kernel build already for other purposes. There's no need to do
>any
>> actual calculation here to extract the last 8 characters (and the
>leading
>> `0x' prefix). At worst you can write a small C program, compile it
>with
>> the build system compiler and run, as we already do for some stuff.
>>
>> Maciej
--
Jiaxun Yang
next prev parent reply other threads:[~2020-04-06 11:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-05 8:24 [PATCH] MIPS: malta: Set load address for 32bit kernel correctly Jiaxun Yang
2020-04-05 16:47 ` Maciej W. Rozycki
2020-04-05 16:53 ` Jiaxun Yang
2020-04-05 17:23 ` Maciej W. Rozycki
2020-04-06 10:57 ` YunQiang Su
2020-04-06 11:10 ` Jiaxun Yang [this message]
2020-04-06 16:43 ` Fangrui Song
2020-04-07 8:06 ` [PATCH v2] MIPS: Truncate load-y into 32bit for 32bit kernel Jiaxun Yang
2020-04-07 17:21 ` Nick Desaulniers
2020-04-07 18:00 ` Fangrui Song
2020-04-07 18:10 ` Maciej W. Rozycki
2020-04-10 9:06 ` [PATCH v3] MIPS: Truncate link address " Jiaxun Yang
2020-04-10 20:45 ` Kees Cook
2020-04-10 23:40 ` Maciej W. Rozycki
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