[Buildroot] [PATCH V3 RESEND 0/5] Add ILP32 support in aarch64
Romain Naour
romain.naour at gmail.com
Wed Jan 20 21:26:22 UTC 2016
Hi Bamvor,
Le 19/01/2016 05:00, Bamvor Zhang Jian a écrit :
> Hi, Romain
>
> On 01/16/2016 11:25 PM, Romain Naour wrote:
>> Hello Bamvor,
>>
>> Le 13/08/2015 03:16, Bamvor Jian Zhang a écrit :
>>> This is third version of my patches. This previous versions are
>>> here[1][2]. The previous discussion, Gustavo agree that only external
>>> toolchain is in consideration at this time. I will try to work on the
>>> buildroot toolchain after current series patch is upstreamed.
>>>
>>> ILP32 is very useful when the user want to migrate from arm 32bit to
>>> 64bit with minimal risk. There is almost no code changes after
>>> migration. ILP32 could get the better performance compare with arm
>>> 32bit (use 64bit register and instruction instead of 32bit one) and
>>> aarch64 LP64 (the default ABI in aarch64).
>>>
>>> Our test show that the performance of ILP32 is roughly 10% better than
>>> arm64 LP64 while the footprint is 86% of LP64. Because of these, It is
>>> useful for both embedded and enterprise system.
>>>
>>> Here is the details definition of ILP32:
>>> ILP32 is elf32 with aarch64 assembly and is compiled by 64bit compiler.
>>> Refer the following table:
>>>
>>> \- | arm 32bit | arm64 ILP32 | arm64 LP64
>>> ----------------|-------------|-------------|-------------
>>> instruction set | armv7-a | armv8-a | armv8-a
>>> int | 32bit | 32bit | 32bit
>>> long | 32bit | **32bit** | 64bit
>>> pointer | 32bit | **32bit** | 64bit
>>>
>>> LP64 is the default ABI on arm64(Implies -mabi=lp64 while compiling),
>>> and the kernel remains in LP64 no matter ILP32 enables or not.
>>>
>>> These series patches introduce the big endian support in aarch64 and
>>> then add ILP32 special filename and menuconfig step by step.
>>>
>>> The test of build is based on linaro kernel[3] and toolchain built by
>>> linaro ABE environment[4], anyone could built this toolchain through
>>> the simpile abe script.
>>>
>>> This is my first time I try to contribute the buildroot, feedback is
>>> very appreciated. Sorry if there are some coding style issues.
>>
>> Thanks for this series and sorry for the long delay to reply...
>>
>> I tried to build a aarch64 ilp32 toolchain using the current abe master but it
>> seems that ilp32 support is not mainline yet.
>> I'm not sure we want to modify the Buildroot external toolchain code to use an
>> "experimental" toolchain (origin/will/ilp32 branch).
>>
>> Can you provide the command lines you used to build the toolchain ? on which abe
>> branch ? Otherwise we can't test your series.
> You could find the toolchain here[1]
Thanks but this is not a cross-toolchain:
file bin/aarch64-ilp32-linux-gnu-gcc
bin/aarch64-ilp32-linux-gnu-gcc: ELF 64-bit LSB executable, ARM aarch64, version
1 (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1, for
GNU/Linux 3.7.0, BuildID[sha1]=0727b9d5c173c83568f5d19cfc87a05540ec8b77, not
stripped
It seems that's a native toolchain.
It should be something like (from aarch64-linaro 2015.08)
file bin/aarch64-linux-gnu-gcc
bin/aarch64-linux-gnu-gcc: ELF 64-bit LSB executable, x86-64, version 1 (SYSV),
dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux
2.6.32, BuildID[sha1]=91a19539d0f6b0f38d599db648b4b5760000666a, not stripped
Can you provide a pre-build toolchain or a recipe to rebuild a aarch64 ipl32
toolchain ?
>>
>> Do you know if Linaro plans to release a ipl32 toolchain ?
> It seems that linaro will not release it before patches for ilp32 of kernel and
> glibc upstreamed.
> Here[2] is a status for ilp32 in linaro.
Thanks for the link.
Best regards,
Romain
>
> Regards
>
> Bamvor
>
> [1] http://people.linaro.org/~maxim.kuvyrkov/bench-ilp32/
> [2] https://wiki.linaro.org/Platform/arm64-ilp32
>
>> Best regards,
>> Romain Naour
>>
>>>
>>> changes since v2
>>> 1. rebase on the patch have been .
>>> "827ba46 aarch64: add big endian(aarch64_be) support"
>>> 2. Add "!BR2_aarch64_be" along with "!BR2_aarch64" in patch 1/5 according to
>>> the suggestion from Thomas.
>>> 3. Improve the ifeq in patch 2/5 according to Gustavo.
>>> 4. Do not pass invalid "-mabi" option to ld in patch 3/5 according to Gustavo.
>>>
>>> changes since v1
>>> 1. Avoid mabi issue in gcc 4.8 while build aarch64 lp64.
>>> 2. Change default libc, toolchain for ilp32 build.
>>> 3. Others changes suggested by Gustavo.
>>>
>>> [1] http://lists.busybox.net/pipermail/buildroot/2015-March/122115.html
>>> [2] http://lists.busybox.net/pipermail/buildroot/2015-March/122424.html
>>> [3] https://git.linaro.org/kernel/linux-linaro-tracking.git
>>> [4] https://wiki.linaro.org/ABE
>>>
>>>
>>> Bamvor Jian Zhang (5):
>>> aarch64: align aarch64_be config with aarch64s'
>>> aarch64: ilp32: handle special file name
>>> aarch64: ilp32: add ilp32 compiler and linker flags
>>> aarch64: ilp32: add ilp32 build config
>>> aarch64: ilp32 defconfig examples
>>>
>>> Makefile | 6 +++
>>> arch/Config.in.aarch64 | 36 ++++++++++++++++++
>>> configs/aarch64_be_defconfig | 2 +
>>> configs/aarch64_be_ilp32_defconfig | 8 ++++
>>> configs/aarch64_ilp32_defconfig | 8 ++++
>>> package/Makefile.in | 13 ++++++-
>>> package/binutils/Config.in | 4 +-
>>> package/binutils/Config.in.host | 5 ++-
>>> package/dropwatch/Config.in | 5 ++-
>>> package/gcc/Config.in.host | 11 +++---
>>> package/gdb/Config.in.host | 2 +-
>>> package/gpsd/Config.in | 2 +-
>>> package/lightning/Config.in | 5 ++-
>>> package/nginx/Config.in | 3 +-
>>> package/oprofile/Config.in | 6 ++-
>>> toolchain/Config.in | 2 +
>>> toolchain/helpers.mk | 5 ++-
>>> toolchain/toolchain-buildroot/Config.in | 7 ++--
>>> toolchain/toolchain-external/Config.in | 22 +++++++++++
>>> toolchain/toolchain-external/toolchain-external.mk | 44 +++++++++++++++++++++-
>>> 20 files changed, 169 insertions(+), 27 deletions(-)
>>> create mode 100644 configs/aarch64_be_defconfig
>>> create mode 100644 configs/aarch64_be_ilp32_defconfig
>>> create mode 100644 configs/aarch64_ilp32_defconfig
>>>
>>
>
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