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From: "Maciej W. Rozycki" <macro@linux-mips.org>
To: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-mips@vger.kernel.org, Fangrui Song <maskray@google.com>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] MIPS: malta: Set load address for 32bit kernel correctly
Date: Sun, 5 Apr 2020 18:23:03 +0100 (BST)	[thread overview]
Message-ID: <alpine.LFD.2.21.2004051817310.4156324@eddie.linux-mips.org> (raw)
In-Reply-To: <96C9B1A0-2F89-4650-B0A4-6A6242A2AA0A@flygoat.com>

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 
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

  reply	other threads:[~2020-04-05 17:23 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 [this message]
2020-04-06 10:57       ` YunQiang Su
2020-04-06 11:10         ` Jiaxun Yang
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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