On Mon, 02 Sep 2019 12:03:12 +1000
Michael Ellerman [off-list ref] wrote:

Michal Suchanek [off-list ref] writes:

quoted

On bigendian ppc64 it is common to have 32bit legacy binaries but much
less so on littleendian.  

I think the toolchain people will tell you that there is no 32-bit
little endian ABI defined at all, if anything works it's by accident.

I have seen a piece of software that workarounds code issues on 64bit
by always compiling 32bit code. So it does work in some way. Also it
has been pointed out that you can still switch to BE even with the
'fast-switch' removed.

So I think we should not make this selectable, unless someone puts their
hand up to say they want it and are willing to test it and keep it
working.

I don't really care either way.

Thanks

Michal

cheers

quoted

v3: make configurable
---
 arch/powerpc/Kconfig | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5bab0bb6b833..b0339e892329 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig

@@ -264,8 +264,9 @@ config PANIC_TIMEOUT
 	default 180
 
 config COMPAT
-	bool
-	default y if PPC64
+	bool "Enable support for 32bit binaries"
+	depends on PPC64
+	default y if !CPU_LITTLE_ENDIAN
 	select COMPAT_BINFMT_ELF
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION

-- 
2.22.0