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Date: Sun, 13 Feb 2011 15:03:47 -0800
Message-ID: <AANLkTimH6gYhcDit3E0TMY=i=DT2s1_difMuvr3vkVzk@mail.gmail.com>
Subject: Re: X32 psABI status
From: "H.J. Lu" <hjl.tools@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>, x32-abi@googlegroups.com,
        GCC Development <gcc@gcc.gnu.org>,
        GNU C Library <libc-alpha@sourceware.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "H. Peter Anvin" <hpa@linux.intel.com>
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On Sun, Feb 13, 2011 at 2:57 PM, Arnd Bergmann <arnd@arndb.de> wrote:
>
>> The cost of an entire different ABI layer (supporting a new memory layout)
>> would be enormous, a.k.a. "not worth it", which is why the memory layout
>> of kernel objects needs to be compatible with i386.
>
> Right, this makes sense, you certainly can't redefine all the data
> structures.
>
> What would probably be a good idea is to compare the set of syscalls
> in X32 and asm-generic, and to either eliminate or document the
> differences. You can probably even take the asm-generic syscall numbers,
> even if you keep the i386 data structures.
>

x32 system call number is BASE + 64bit system call number.  It is
easy to keep 64bit and x32 in sync.

-- 
H.J.
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