[PATCH 29/30] x32: Allow x32 to be configured
From: "H. Peter Anvin" <hpa@zytor.com>
Date: 2012-02-20 00:22:04
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: "H. J. Lu" <redacted> At this point, one should be able to build an x32 kernel. Note that for now we depend on CONFIG_IA32_EMULATION. Long term, x32 and IA32 should be detangled. Signed-off-by: H. Peter Anvin <hpa@zytor.com> --- arch/x86/Kconfig | 21 +++++++++++++++++---- 1 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5bed94e..c9d6c9e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig@@ -2165,9 +2165,9 @@ config IA32_EMULATION depends on X86_64 select COMPAT_BINFMT_ELF ---help--- - Include code to run 32-bit programs under a 64-bit kernel. You should - likely turn this on, unless you're 100% sure that you don't have any - 32-bit programs left. + Include code to run legacy 32-bit programs under a + 64-bit kernel. You should likely turn this on, unless you're + 100% sure that you don't have any 32-bit programs left. config IA32_AOUT tristate "IA32 a.out support"
@@ -2175,9 +2175,22 @@ config IA32_AOUT ---help--- Support old a.out binaries in the 32bit emulation. +config X86_X32_ABI + bool "x32 ABI for 64-bit mode (EXPERIMENTAL)" + depends on X86_64 && IA32_EMULATION && EXPERIMENTAL + ---help--- + Include code to run binaries for the x32 native 32-bit ABI + for 64-bit processors. An x32 process gets access to the + full 64-bit register file and wide data path while leaving + pointers at 32 bits for smaller memory footprint. + + You will need a recent binutils (2.22 or later) with + elf32_x86_64 support enabled to compile a kernel with this + option set. + config COMPAT def_bool y - depends on IA32_EMULATION + depends on IA32_EMULATION || X86_X32_ABI config COMPAT_FOR_U64_ALIGNMENT def_bool COMPAT
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1.7.6.5