Re: [PATCH 07/24] arm64: ilp32: add documentation on the ILP32 ABI for ARM64
From: Yury Norov <hidden>
Date: 2018-05-24 12:16:00
Also in:
linux-arch, linux-arm-kernel, linux-doc, lkml
Hi Pavel, On Wed, May 23, 2018 at 04:06:20PM +0200, Pavel Machek wrote:
On Wed 2018-05-16 11:18:52, Yury Norov wrote:quoted
Based on Andrew Pinski's patch-series. Signed-off-by: Yury Norov <redacted>So Andrew's signoff should be here?
Yes it should, but it lost since v4. I'll restore it.
quoted
--- Documentation/arm64/ilp32.txt | 45 +++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 Documentation/arm64/ilp32.txtdiff --git a/Documentation/arm64/ilp32.txt b/Documentation/arm64/ilp32.txt new file mode 100644 index 000000000000..d0fd5109c4b2 --- /dev/null +++ b/Documentation/arm64/ilp32.txt@@ -0,0 +1,45 @@ +ILP32 AARCH64 SYSCALL ABI +========================= + +This document describes the ILP32 syscall ABI and where it differs +from the generic compat linux syscall interface.I was hoping to learn what ILP32 is / what is it good for, but no, this does not tell me... it would be good to do a short explanation here, and maybe reference it from cover letter of the series... Pavel
ILP32 is ABI acronym that means "Integers, Longs and Pointers are 32-bit". And LP64 means "Longs and Pointers are 64-bit". There's AN490 - "ILP32 for AArch64 Whitepaper" from ARM which covers the topic: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dai0490a/ar01s01.html And some talks: http://connect.linaro.org/resource/bkk16/bkk16-305b/ Briefly, ILP32 is 32-bit ABI that works with AARCH64 instruction set. It looks better in some performance tests, and is useful for compatibility with 32-bit legacy code. If you're more familiar with x86 terminology, in ARM world LP64 corresponds to x86_64, AARCH32_EL0 corresponds to x86_32, and ILP32 corresponds to x32 ABI. I'll add link to AN490 in next submission. Yury
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html