[OE-core] [OE-Core][PATCH 00/13] powerpc/powerpc64: Support build with musl as libc

[Serhey Popovych]

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

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2.7.4