Re: [PATCH 00/13] powerpc/powerpc64: Support build with musl as libc

[Khem Raj <raj.khem@gmail.com>]

Serhey

Thanks for doing this work and really a clean pull request with good
explanation that I have seen lately. Good work, For most parts
everything is in order except few places where I have replied
specifically to the patches

On Fri, Dec 14, 2018 at 9:55 AM Serhey Popovych
<serhe.popovych@gmail.com> wrote:
>
> Musl has support for ppc (32bit) and ppc64 (64bit). OE still missing
> several tricks in configuration to make builds possible:
>
>   1) Most important part is that musl implements elfv2 ABI only for
>      64bit PowerPC. That ABI is default for little-endian but supports
>      big-endian too. Historically elfv1 ABI is used for big-endian
>      PowerPC.
>
>   2) Using uncommon elfv2 ABI for big-endian requires to disable all
>      assembler optimizations in openssl: unfortunately I can't find more
>      smart way at the moment.
>
>   3) LDSO path need to be adjusted to support /lib64 path which is
>      default for powerpc64 (see bitbake.conf) instead of $baselibdir.
>
>   4) Default library search path is hardcoded to
>      "/lib:/usr/local/lib:/usr/lib": pass -DSYSLIBDIR and -DLIBDIR and
>      use them to set path.
>
>   5) Need to add more tweaks to patch that adds --with-ldbl-128 knob
>      to gcc configure: there is a set of functions that use TFtype in
>      ppc64-fp.c in libgcc. This should be compatible with glibc.
>
>   6) Disable qemu-userspace for powerpc64 bit: there is no support.
>      While there change qemuwrapper to exit explicitly to fix infinite
>      execution in do_rootfs() task when building on IBM POWER8 machine.
>
>   7) Misc fixes that map powerpc-linux-musl python3 triplet to
>      powerpc-linux-gnu, remove conflicting sed in do_configure() vs
>      patch settings in gcc and fix DEFAULTTUNE settings for various
>      IBM POWER platforms.
>
> Build is done on IBM POWER8 machine running RHEL7:
>
> Images:
> -------
>     core-image-sato
>     core-image-full-cmdline
>
> For powerpc64:
> --------------
>               glibc                musl
>          systemd sysvinit    systemd sysvinit
>   gcc-7.3   y       y           y       y
>   gcc-8.2   y       y           y       y
>
> For powerpc:
> ------------
>               glibc                musl
>          systemd sysvinit    systemd sysvinit
>   gcc-7.3   n       x           x       x      (*)
>   gcc-8.2   y       y           y       y
>
> Note that gcc-7.3 builds for 32bit powerpc fail due to:
>   https://bugzilla.yoctoproject.org/show_bug.cgi?id=11754
>
> Kernel/images are boot tested using KVM-HV on IBM POWER8.
>
> Serhey Popovych (13):
>   lib/oe/elf.py: Add powerpc64 architecture definition for musl
>   tune-power[5-7].inc: Fix DEFAULTTUNE values
>   tune-power[5-7].inc: Disable QEMU usermode usage
>   qemuwrapper: Explicitly exit in case of no qemu supported for target
>   arch-powerpc64.inc: Use elfv2 ABI when building with musl
>   musl: Create default library search path based on configuration
>   musl: Ensure GLIBC_LDSO symlink target does not exist on reinstall
>   openssl: Skip assembler optimized code for powerpc64 with musl
>   python3: Fix do_configure check platform triplet error (2)
>   gcc: Fix preprocessor redefines for header pathes
>   gcc: More places to patch to disable ldbl 128 for musl on PPC
>   gcc: Enable secureplt for powerpc64 target too
>   gcc-7.3,gcc-8.2: Use variable SYSTEMLIBS_DIR instead of hardcoding it
>     for ppc64
>
>  .../machine/include/powerpc/arch-powerpc64.inc     |   3 +
>  meta/conf/machine/include/tune-power5.inc          |   5 +-
>  meta/conf/machine/include/tune-power6.inc          |   5 +-
>  meta/conf/machine/include/tune-power7.inc          |   5 +-
>  meta/lib/oe/elf.py                                 |   1 +
>  .../openssl/openssl10_1.0.2q.bb                    |   1 +
>  .../recipes-connectivity/openssl/openssl_1.1.1a.bb |   1 +
>  ...slibdir-and-libdir-as-default-pathes-to-l.patch |  61 ++++
>  meta/recipes-core/musl/musl_git.bb                 |   3 +-
>  meta/recipes-devtools/gcc/gcc-7.3.inc              |   1 +
>  ...Ensure-target-gcc-headers-can-be-included.patch |  36 --
>  ...44-libgcc-Add-knob-to-use-ldbl-128-on-ppc.patch | 391 ++++++++++++++++++++-
>  ...werpc-powerpc64-Add-support-for-musl-ldso.patch |  31 ++
>  meta/recipes-devtools/gcc/gcc-8.2.inc              |   1 +
>  ...Ensure-target-gcc-headers-can-be-included.patch |  36 --
>  ...34-libgcc-Add-knob-to-use-ldbl-128-on-ppc.patch | 342 +++++++++++++++++-
>  ...werpc-powerpc64-Add-support-for-musl-ldso.patch |  31 ++
>  meta/recipes-devtools/gcc/gcc-common.inc           |   2 +-
>  .../tweak-MULTIARCH-for-powerpc-linux-musl.patch   |  40 +++
>  meta/recipes-devtools/python/python3_3.5.6.bb      |   1 +
>  .../recipes-devtools/qemu/qemuwrapper-cross_1.0.bb |   3 +-
>  21 files changed, 920 insertions(+), 80 deletions(-)
>  create mode 100644 meta/recipes-core/musl/musl/0002-ldso-Use-syslibdir-and-libdir-as-default-pathes-to-l.patch
>  create mode 100644 meta/recipes-devtools/gcc/gcc-7.3/0050-powerpc-powerpc64-Add-support-for-musl-ldso.patch
>  create mode 100644 meta/recipes-devtools/gcc/gcc-8.2/0042-powerpc-powerpc64-Add-support-for-musl-ldso.patch
>  create mode 100644 meta/recipes-devtools/python/python3/tweak-MULTIARCH-for-powerpc-linux-musl.patch
>
> --
> 2.7.4
>
> --
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