kbuild: Introduce Kconfig symbol for linking vmlinux with relocations

Some architectures build vmlinux with static relocations preserved, but
strip them again from the final vmlinux image. Arch spec

kbuild: Introduce Kconfig symbol for linking vmlinux with relocations

Some architectures build vmlinux with static relocations preserved, but
strip them again from the final vmlinux image. Arch specific tools
consume these static relocations in order to construct relocation tables
for KASLR.

The fact that vmlinux is created, consumed and subsequently updated goes
against the typical, declarative paradigm used by Make, which is based
on rules and dependencies. So as a first step towards cleaning this up,
introduce a Kconfig symbol to declare that the arch wants to consume the
static relocations emitted into vmlinux. This will be wired up further
in subsequent patches.

Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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MIPS: migrate to generic rule for built-in DTBs

Commit 654102df2ac2 ("kbuild: add generic support for built-in boot
DTBs") introduced generic support for built-in DTBs.

Select GENERIC_BUILTIN_DTB a

MIPS: migrate to generic rule for built-in DTBs

Commit 654102df2ac2 ("kbuild: add generic support for built-in boot
DTBs") introduced generic support for built-in DTBs.

Select GENERIC_BUILTIN_DTB and BUILTIN_DTB_ALL when the built-in DTB
support is enabled.

DTBs compiled under arch/mips/boot/dts/ will be wrapped by the generic
rule in scripts/Makefile.vmlinux.

Signed-off-by: Masahiro Yamada <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Fix fallback march for SB1

Fallback march for SB1 should be mips64 instead of mips64r1.

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/2024071118

MIPS: Fix fallback march for SB1

Fallback march for SB1 should be mips64 instead of mips64r1.

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Fixes: bfc0a330c1b4 ("MIPS: Fallback CPU -march flag to ISA level if unsupported")
Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Loongson64: test for -march=loongson3a cflag

Currently march flag is hardcoded to loongson3a for GCC and
mips64r2 for clang.

We can actually test it to simplify the code.

Signed-off-by: Jiax

MIPS: Loongson64: test for -march=loongson3a cflag

Currently march flag is hardcoded to loongson3a for GCC and
mips64r2 for clang.

We can actually test it to simplify the code.

Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: BMIPS: Drop unnecessary assembler flag

Nowadays GCC will always pass -march flag to gas, so there
is no need to pass another mips32 flag to assembler.

Signed-off-by: Jiaxun Yang <jiaxun.yang@

MIPS: BMIPS: Drop unnecessary assembler flag

Nowadays GCC will always pass -march flag to gas, so there
is no need to pass another mips32 flag to assembler.

Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Fallback CPU -march flag to ISA level if unsupported

LLVM does not implement some of -march options. However those options
are not mandatory for kernel to build for those CPUs.

Fallback -marc

MIPS: Fallback CPU -march flag to ISA level if unsupported

LLVM does not implement some of -march options. However those options
are not mandatory for kernel to build for those CPUs.

Fallback -march CFLAG to ISA level if unsupported by toolchain so
we can get those kernel to build with LLVM.

Link: https://github.com/ClangBuiltLinux/linux/issues/1544
Reported-by: Nathan Chancellor <[email protected]>
Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Remove cc-option checks for -march=octeon

Nowadays our minimal supported GCC/Clang all support -march=octeon.
Remove cc-option checks to simplify code.

Signed-off-by: Jiaxun Yang <jiaxun.yang

MIPS: Remove cc-option checks for -march=octeon

Nowadays our minimal supported GCC/Clang all support -march=octeon.
Remove cc-option checks to simplify code.

Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Probe toolchain support of -msym32

msym32 is not supported by LLVM toolchain.
Workaround by probe toolchain support of msym32 for KBUILD_SYM32
feature.

Link: https://github.com/ClangBuiltLinu

MIPS: Probe toolchain support of -msym32

msym32 is not supported by LLVM toolchain.
Workaround by probe toolchain support of msym32 for KBUILD_SYM32
feature.

Link: https://github.com/ClangBuiltLinux/linux/issues/1544
Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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Revert MIPS: Loongson: Fix build error when make modules_install

Revert commit 531b3d1195d0 ("MIPS: Loongson: Fix build error when make
modules_install"), which made `-march=loongson2e', `-march=loo

Revert MIPS: Loongson: Fix build error when make modules_install

Revert commit 531b3d1195d0 ("MIPS: Loongson: Fix build error when make
modules_install"), which made `-march=loongson2e', `-march=loongson2f',
and `-march=loongson3a' compilation options probed for even though GCC
has supported them since 4.4.0, 4.4.0, and 4.6.0 respectively, which is
below our current minimum requirement of 5.1, in an attempt to work
around for the `cc-option' `make' function being undefined with `make'
targets that do not use the compiler. The workaround has now been made
obsolete, by querying the `need-compiler' variable instead so as to make
sure the compiler isn't called for non-build targets.

Verified with `fuloong2e_defconfig' and the `modules_install' target.

Signed-off-by: Maciej W. Rozycki <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Only fiddle with CHECKFLAGS if `need-compiler'

We have originally guarded fiddling with CHECKFLAGS in our arch Makefile
by checking for the CONFIG_MIPS variable, not set for targets such as
`d

MIPS: Only fiddle with CHECKFLAGS if `need-compiler'

We have originally guarded fiddling with CHECKFLAGS in our arch Makefile
by checking for the CONFIG_MIPS variable, not set for targets such as
`distclean', etc. that neither include `.config' nor use the compiler.

Starting from commit 805b2e1d427a ("kbuild: include Makefile.compiler
only when compiler is needed") we have had a generic `need-compiler'
variable explicitly telling us if the compiler will be used and thus its
capabilities need to be checked and expressed in the form of compilation
flags. If this variable is not set, then `make' functions such as
`cc-option' are undefined, causing all kinds of weirdness to happen if
we expect specific results to be returned, most recently:

cc1: error: '-mloongson-mmi' must be used with '-mhard-float'

messages with configurations such as `fuloong2e_defconfig' and the
`modules_install' target, which does include `.config' and yet does not
use the compiler.

Replace the check for CONFIG_MIPS with one for `need-compiler' instead,
so as to prevent the compiler from being ever called for CHECKFLAGS when
not needed.

Reported-by: Guillaume Tucker <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]/
Signed-off-by: Maciej W. Rozycki <[email protected]>
Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed")
Cc: [email protected] # v5.13+
Reported-by: "kernelci.org bot" <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Fix CONFIG_CPU_DADDI_WORKAROUNDS `modules_install' regression

Remove a build-time check for the presence of the GCC `-msym32' option.
This option has been there since GCC 4.1.0, which is below

MIPS: Fix CONFIG_CPU_DADDI_WORKAROUNDS `modules_install' regression

Remove a build-time check for the presence of the GCC `-msym32' option.
This option has been there since GCC 4.1.0, which is below the minimum
required as at commit 805b2e1d427a ("kbuild: include Makefile.compiler
only when compiler is needed"), when an error message:

arch/mips/Makefile:306: *** CONFIG_CPU_DADDI_WORKAROUNDS unsupported without -msym32. Stop.

started to trigger for the `modules_install' target with configurations
such as `decstation_64_defconfig' that set CONFIG_CPU_DADDI_WORKAROUNDS,
because said commit has made `cc-option-yn' an undefined function for
non-build targets.

Reported-by: Jan-Benedict Glaw <[email protected]>
Signed-off-by: Maciej W. Rozycki <[email protected]>
Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed")
Cc: [email protected] # v5.13+
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Loongson: Fix build error when make modules_install

After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of
cc-ifversion") we get a build error when make modules_install:

cc1:

MIPS: Loongson: Fix build error when make modules_install

After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of
cc-ifversion") we get a build error when make modules_install:

cc1: error: '-mloongson-mmi' must be used with '-mhard-float'

The reason is when make modules_install, 'call cc-option' doesn't work
in $(KBUILD_CFLAGS) of 'CHECKFLAGS'. Then there is no -mno-loongson-mmi
applied and -march=loongson3a enable MMI instructions.

To be detail, the error message comes from the CHECKFLAGS invocation of
$(CC) but it has no impact on the final result of make modules_install,
it is purely a cosmetic issue. The error occurs because cc-option is
defined in scripts/Makefile.compiler, which is not included in Makefile
when running 'make modules_install', as install targets are not supposed
to require the compiler; see commit 805b2e1d427aab4b ("kbuild: include
Makefile.compiler only when compiler is needed"). As a result, the call
to check for '-mno-loongson-mmi' just never happens.

Fix this by partially reverting to the old logic, use 'call cc-option'
to conditionally apply -march=loongson3a and -march=mips64r2.

By the way, Loongson-2E/2F is also broken in commit 13ceb48bc19c563e05f4
("MIPS: Loongson2ef: Remove unnecessary {as,cc}-option calls") so fix it
together.

Fixes: 13ceb48bc19c563e05f4 ("MIPS: Loongson2ef: Remove unnecessary {as,cc}-option calls")
Fixes: 0e96ea5c3eb5904e5dc2 ("MIPS: Loongson64: Clean up use of cc-ifversion")
Cc: [email protected]
Cc: Feiyang Chen <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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mips: Include KBUILD_CPPFLAGS in CHECKFLAGS invocation

A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to
KBUILD_CPPFLAGS so that '--target' is available while preprocessing.
When that

mips: Include KBUILD_CPPFLAGS in CHECKFLAGS invocation

A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to
KBUILD_CPPFLAGS so that '--target' is available while preprocessing.
When that occurs, the following error appears when building ARCH=mips
with clang (tip of tree error shown):

clang: error: unsupported option '-mabi=' for target 'x86_64-pc-linux-gnu'

Add KBUILD_CPPFLAGS in the CHECKFLAGS invocation to keep everything
working after the move.

Signed-off-by: Nathan Chancellor <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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MIPS: Loongson: Move arch cflags to MIPS top level Makefile

Arch cflags should be independent to Platform.

Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <t

MIPS: Loongson: Move arch cflags to MIPS top level Makefile

Arch cflags should be independent to Platform.

Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Prefer cc-option for additions to cflags

A future change will switch as-option to use KBUILD_AFLAGS instead of
KBUILD_CFLAGS to allow clang to drop -Qunused-arguments, which may cause
issues i

MIPS: Prefer cc-option for additions to cflags

A future change will switch as-option to use KBUILD_AFLAGS instead of
KBUILD_CFLAGS to allow clang to drop -Qunused-arguments, which may cause
issues if the flag being tested requires a flag previously added to
KBUILD_CFLAGS but not KBUILD_AFLAGS. Use cc-option for cflags additions
so that the flags are tested properly.

Signed-off-by: Nathan Chancellor <[email protected]>
Acked-by: Thomas Bogendoerfer <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Tested-by: Linux Kernel Functional Testing <[email protected]>
Tested-by: Anders Roxell <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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MIPS: Always use -Wa,-msoft-float and eliminate GAS_HAS_SET_HARDFLOAT

-Wa,-msoft-float is tested with as-option, which will be a problem for
clang with an upcoming change to move as-option to use KB

MIPS: Always use -Wa,-msoft-float and eliminate GAS_HAS_SET_HARDFLOAT

-Wa,-msoft-float is tested with as-option, which will be a problem for
clang with an upcoming change to move as-option to use KBUILD_AFLAGS
instead of KBUILD_CFLAGS due to a lack of '-mno-abicalls' in
KBUILD_AFLAGS at the point that this check occurs; $(cflags-y) is added
to KBUILD_AFLAGS towards the end of this file.

clang: error: ignoring '-fno-PIE' option as it cannot be used with implicit usage of -mabicalls and the N64 ABI [-Werror,-Woption-ignored]

This could be resolved by switching to a cc-option check but
'$(cflags-y)' would need to be added so that '-mno-abicalls' is present
for the test. However, this check is no longer necessary, as
-msoft-float is supported by all supported assembler versions (GNU as
2.25+ and LLVM 11+). Eliminate GAS_HAS_SET_HARDFLOAT and all of its
uses, inlining SET_HARDFLOAT where necessary.

Link: https://lore.kernel.org/[email protected]/
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
Acked-by: Thomas Bogendoerfer <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Tested-by: Linux Kernel Functional Testing <[email protected]>
Tested-by: Anders Roxell <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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MIPS: Use "grep -E" instead of "egrep"

The latest version of grep claims the egrep is now obsolete so the build
now contains warnings that look like:
egrep: warning: egrep is obsolescent; using gre

MIPS: Use "grep -E" instead of "egrep"

The latest version of grep claims the egrep is now obsolete so the build
now contains warnings that look like:
egrep: warning: egrep is obsolescent; using grep -E
fix this up by moving the related file to use "grep -E" instead.

Here are the steps to install the latest grep:

wget http://ftp.gnu.org/gnu/grep/grep-3.8.tar.gz
tar xf grep-3.8.tar.gz
cd grep-3.8 && ./configure && make
sudo make install
export PATH=/usr/local/bin:$PATH

Signed-off-by: Tiezhu Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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kbuild: remove head-y syntax

Kbuild puts the objects listed in head-y at the head of vmlinux.
Conventionally, we do this for head*.S, which contains the kernel entry
point.

A counter approach is to

kbuild: remove head-y syntax

Kbuild puts the objects listed in head-y at the head of vmlinux.
Conventionally, we do this for head*.S, which contains the kernel entry
point.

A counter approach is to control the section order by the linker script.
Actually, the code marked as __HEAD goes into the ".head.text" section,
which is placed before the normal ".text" section.

I do not know if both of them are needed. From the build system
perspective, head-y is not mandatory. If you can achieve the proper code
placement by the linker script only, it would be cleaner.

I collected the current head-y objects into head-object-list.txt. It is
a whitelist. My hope is it will be reduced in the long run.

Signed-off-by: Masahiro Yamada <[email protected]>
Tested-by: Nick Desaulniers <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>

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MIPS: Remove VR41xx support

No (active) developer owns this hardware, so let's remove Linux support.

Signed-off-by: Thomas Bogendoerfer <[email protected]>

mips: Always permit to build u-boot images

The platforms where the kernel should be loaded above 0x8000.0000 do not
support loading u-boot images, that doesn't mean that we shouldn't be
able to gene

mips: Always permit to build u-boot images

The platforms where the kernel should be loaded above 0x8000.0000 do not
support loading u-boot images, that doesn't mean that we shouldn't be
able to generate them.

Additionally, since commit 79876cc1d7b8 ("MIPS: new Kconfig option
ZBOOT_LOAD_ADDRESS"), the $(zload-y) variable was no longer hardcoded,
which made it impossible to use the uzImage.bin target.

Fixes: 79876cc1d7b8 ("MIPS: new Kconfig option ZBOOT_LOAD_ADDRESS")
Cc: <[email protected]>
Signed-off-by: Paul Cercueil <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: Remove TX39XX support

No (active) developer owns this hardware, so let's remove Linux support.

Signed-off-by: Thomas Bogendoerfer <[email protected]>
Acked-by: Guenter Roeck <linux@ro

MIPS: Remove TX39XX support

No (active) developer owns this hardware, so let's remove Linux support.

Signed-off-by: Thomas Bogendoerfer <[email protected]>
Acked-by: Guenter Roeck <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Acked-by: Atsushi Nemoto <[email protected]>

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MIPS: Makefile: Remove "ifdef need-compiler" for Kbuild.platforms

After commit 13ceb48bc19c ("MIPS: Loongson2ef: Remove unnecessary
{as,cc}-option calls"), no need to use "ifdef need-compiler" for
K

MIPS: Makefile: Remove "ifdef need-compiler" for Kbuild.platforms

After commit 13ceb48bc19c ("MIPS: Loongson2ef: Remove unnecessary
{as,cc}-option calls"), no need to use "ifdef need-compiler" for
Kbuild.platforms, because the cause of the build issue mentioned
in commit 0706f74f719e ("MIPS: fix *-pkg builds for loongson2ef
platform") has been disappeared, so just remove it.

Signed-off-by: Tiezhu Yang <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Reviewed-by: Masahiro Yamada <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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MIPS: fix *-pkg builds for loongson2ef platform

Since commit 805b2e1d427a ("kbuild: include Makefile.compiler only when
compiler is needed"), package builds for the loongson2f platform fail.

$ ma

MIPS: fix *-pkg builds for loongson2ef platform

Since commit 805b2e1d427a ("kbuild: include Makefile.compiler only when
compiler is needed"), package builds for the loongson2f platform fail.

$ make ARCH=mips CROSS_COMPILE=mips64-linux- lemote2f_defconfig bindeb-pkg
[ snip ]
sh ./scripts/package/builddeb
arch/mips/loongson2ef//Platform:36: *** only binutils >= 2.20.2 have needed option -mfix-loongson2f-nop. Stop.
cp: cannot stat '': No such file or directory
make[5]: *** [scripts/Makefile.package:87: intdeb-pkg] Error 1
make[4]: *** [Makefile:1558: intdeb-pkg] Error 2
make[3]: *** [debian/rules:13: binary-arch] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
make[2]: *** [scripts/Makefile.package:83: bindeb-pkg] Error 2
make[1]: *** [Makefile:1558: bindeb-pkg] Error 2
make: *** [Makefile:350: __build_one_by_one] Error 2

The reason is because "make image_name" fails.

$ make ARCH=mips CROSS_COMPILE=mips64-linux- image_name
arch/mips/loongson2ef//Platform:36: *** only binutils >= 2.20.2 have needed option -mfix-loongson2f-nop. Stop.

In general, adding $(error ...) in the parse stage is troublesome,
and it is pointless to check toolchains even if we are not building
anything. Do not include Kbuild.platform in such cases.

Fixes: 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed")
Reported-by: Jason Self <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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kbuild: use more subdir- for visiting subdirectories while cleaning

Documentation/kbuild/makefiles.rst suggests to use "archclean" for
cleaning arch/$(SRCARCH)/boot/, but it is not a hard requiremen

kbuild: use more subdir- for visiting subdirectories while cleaning

Documentation/kbuild/makefiles.rst suggests to use "archclean" for
cleaning arch/$(SRCARCH)/boot/, but it is not a hard requirement.

Since commit d92cc4d51643 ("kbuild: require all architectures to have
arch/$(SRCARCH)/Kbuild"), we can use the "subdir- += boot" trick for
all architectures. This can take advantage of the parallel option (-j)
for "make clean".

I also cleaned up the comments in arch/$(SRCARCH)/Makefile. The "archdep"
target no longer exists.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Acked-by: Michael Ellerman <[email protected]> (powerpc)

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MIPS: Make a alias for pistachio_defconfig

For those who miss the old defconfig, make a alias to generic
kernel.

Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoer

MIPS: Make a alias for pistachio_defconfig

For those who miss the old defconfig, make a alias to generic
kernel.

Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

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