# git rev-parse -q --verify e41c4d61fad73e2e41ecdade7c163be8aa9d77e8^{commit}
e41c4d61fad73e2e41ecdade7c163be8aa9d77e8
already have revision, skipping fetch
# git checkout -q -f -B kisskb e41c4d61fad73e2e41ecdade7c163be8aa9d77e8
# git clean -qxdf
# < git log -1
# commit e41c4d61fad73e2e41ecdade7c163be8aa9d77e8
# Author: Jordan Niethe <jniethe5@gmail.com>
# Date:   Tue Sep 17 10:46:05 2019 +1000
# 
#     powerpc/64s: Set reserved PCR bits
#     
#     Currently the reserved bits of the Processor Compatibility
#     Register (PCR) are cleared as per the Programming Note in Section
#     1.3.3 of version 3.0B of the Power ISA. This causes all new
#     architecture features to be made available when running on newer
#     processors with new architecture features added to the PCR as bits
#     must be set to disable a given feature.
#     
#     For example to disable new features added as part of Version 2.07 of
#     the ISA the corresponding bit in the PCR needs to be set.
#     
#     As new processor features generally require explicit kernel support
#     they should be disabled until such support is implemented. Therefore
#     kernels should set all unknown/reserved bits in the PCR such that any
#     new architecture features which the kernel does not currently know
#     about get disabled.
#     
#     An update is planned to the ISA to clarify that the PCR is an
#     exception to the Programming Note on reserved bits in Section 1.3.3.
#     
#     Signed-off-by: Alistair Popple <alistair@popple.id.au>
#     Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
#     Tested-by: Joel Stanley <joel@jms.id.au>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20190917004605.22471-2-alistair@popple.id.au
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 e41c4d61fad73e2e41ecdade7c163be8aa9d77e8
# < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_40x_klondike_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  40x/klondike_defconfig
# make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_40x_klondike_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
/kisskb/src/arch/powerpc/kernel/head_40x.S: Assembler messages:
/kisskb/src/arch/powerpc/kernel/head_40x.S:802: Warning: invalid register expression
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_40x_klondike_defconfig_powerpc-gcc5
# Build took: 0:00:30.507300