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Add ILP32 support in aarch64

RFC PATCH Superseded Zhang Jian (Bamvor) 3 participants 17 messages Mar 18, 2015 – Jul 13, 2015 Kbuild

v2 of 3 Superseded Latest is v3 →

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Zhang Jian (Bamvor)

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#0 lore raw

v2 cover Add ILP32 support in aarch64

This is second version of my patches. This previous version is here[1]. The previous discussion, Gustavo agree that only external toolchain is in consideration at this time. I will try to work on the buildroot toolchain after current series patch is upstreamed.

ILP32 is very useful when the user want to migrate from arm 32bit to 64bit with minimal risk. There is no code changes and almost no footprint changes after migration. ILP32 could get the better performance compare with arm 32bit (use 64bit register and instruction instead of 32bit one) and aarch64 LP64 (aarch64 default ABI).

Our test show that the performance of ILP32 is roughly 10% better than arm64 LP64 while the footprint is 86% of LP64. Because of these, It is useful for both embedded and enterprise system.

Here is the details definition of ILP32:
ILP32 is elf32 with aarch64 assembly and is compiled by 64bit compiler. Refer the following table:

  \-            |  arm 32bit  | arm64 ILP32 | arm64 LP64
----------------|-------------|-------------|-------------
instruction set |   armv7-a   |   armv8-a   |   armv8-a
int             |   32bit     |   32bit     |   32bit
long            |   32bit     | **32bit**   |   64bit
pointer         |   32bit     | **32bit**   |   64bit

LP64 is the default ABI on arm64(Implies -mabi=lp64 while compiling), and the kernel remains in LP64 no matter ILP32 enables or not.

These series patches introduce the big endian support in aarch64 and then add ILP32 special filename and menuconfig step by step.

The test of build is based on linaro kernel [2] and toolchain built by linaro ABE environment[3], anyone could built this toolchain through the simpile abe script.

This is my first time I try to contribute the buildroot, feedback is very appreciated. Sorry if there are some coding style issues.

changes since v1

1.  avoid mabi issue in gcc 4.8 while build aarch64 lp64.
2.  change default libc, toolchain for ilp32 build.
3.  others changes suggested by Gustavo.

[1] http://lists.busybox.net/pipermail/buildroot/2015-March/122115.html
[2] https://git.linaro.org/kernel/linux-linaro-tracking.git
[3] https://wiki.linaro.org/ABE

Zhang Jian(Bamvor) (5):
aarch64: add big endian(aarch64_be) support
aarch64: ilp32: handle special file name
aarch64: ilp32: add ilp32 compiler and linker flags
aarch64: ilp32: add ilp32 build config
aarch64: ilp32 defconfig examples

 Makefile                                           | 11 +++++-
 arch/Config.in                                     | 12 +++++--
 arch/Config.in.aarch64                             | 40 ++++++++++++++++++++-
 configs/aarch64_be_defconfig                       |  2 ++
 configs/aarch64_be_ilp32_defconfig                 |  8 +++++
 configs/aarch64_ilp32_defconfig                    |  8 +++++
 package/Makefile.in                                | 10 +++++-
 package/gcc/Config.in.host                         |  3 +-
 toolchain/Config.in                                |  2 ++
 toolchain/helpers.mk                               |  4 +--
 toolchain/toolchain-buildroot/Config.in            | 27 +++++++-------
 toolchain/toolchain-external/Config.in             | 20 +++++++++++
 toolchain/toolchain-external/toolchain-external.mk | 41 ++++++++++++++++++++--
 13 files changed, 165 insertions(+), 23 deletions(-)
 create mode 100644 configs/aarch64_be_defconfig
 create mode 100644 configs/aarch64_be_ilp32_defconfig
 create mode 100644 configs/aarch64_ilp32_defconfig
Signature · 1 line
1.8.4.5
author
#1 lore raw

RFC PATCH v2 1/5 aarch64: add big endian(aarch64_be) support

Add aarch64_be support. Note that CONFIG_CPU_BIG_ENDIAN should be defined in kernel config when building a big endian kernel.

Signed-off-by Zhang Jian(Bamvor) <[email protected]>
---
 Makefile                                |  2 +-
 arch/Config.in                          | 12 ++++++++++--
 arch/Config.in.aarch64                  |  5 ++++-
 toolchain/toolchain-buildroot/Config.in | 27 ++++++++++++++-------------
 4 files changed, 29 insertions(+), 17 deletions(-)
Makefile +1 -1
index af043a3..84402be 100644
@@ -315,7 +315,7 @@ KERNEL_ARCH := $(shell echo "$(ARCH)" | sed -e "s/-.*//" \
 	-e s/arcle/arc/ \
 	-e s/arceb/arc/ \
 	-e s/arm.*/arm/ -e s/sa110/arm/ \
-	-e s/aarch64/arm64/ \
+	-e s/aarch64.*/arm64/ \
 	-e s/bfin/blackfin/ \
 	-e s/parisc64/parisc/ \
 	-e s/powerpc64.*/powerpc/ \
arch/Config.in +10 -2
index 16ad8be..4e4ab37 100644
@@ -46,7 +46,15 @@ config BR2_armeb
 	  http://en.wikipedia.org/wiki/ARM
 
 config BR2_aarch64
-	bool "AArch64"
+	bool "AArch64 (little endian)"
+	select BR2_ARCH_IS_64
+	help
+	  Aarch64 is a 64-bit architecture developed by ARM Holdings.
+	  http://www.arm.com/products/processors/instruction-set-architectures/armv8-architecture.php
+	  http://en.wikipedia.org/wiki/ARM
+
+config BR2_aarch64_be
+	bool "AArch64 (big endian)"
 	select BR2_ARCH_IS_64
 	help
 	  Aarch64 is a 64-bit architecture developed by ARM Holdings.

@@ -309,7 +317,7 @@ if BR2_arm || BR2_armeb
 source "arch/Config.in.arm"
 endif
 
-if BR2_aarch64
+if BR2_aarch64 || BR2_aarch64_be
 source "arch/Config.in.aarch64"
 endif
arch/Config.in.aarch64 +4 -1
index 2e79870..9830302 100644
@@ -1,8 +1,11 @@
 config BR2_ARCH
 	default "aarch64"	if BR2_aarch64
+	default "aarch64_be"	if BR2_aarch64_be
 
 config BR2_ENDIAN
-	default "LITTLE"
+	default "LITTLE" if BR2_aarch64
+	default "BIG"	 if BR2_aarch64_be
 
 config BR2_ARCH_HAS_ATOMICS
 	default y
+
toolchain/toolchain-buildroot/Config.in +14 -13
index d4e3bcc..1c2525d 100644
@@ -23,8 +23,8 @@ source "package/linux-headers/Config.in.host"
 choice
 	prompt "C library"
 	default BR2_TOOLCHAIN_UCLIBC
-	default BR2_TOOLCHAIN_BUILDROOT_GLIBC if BR2_aarch64 || BR2_microblaze \
-		|| BR2_mips64 || BR2_mips64el || BR2_powerpc64
+	default BR2_TOOLCHAIN_BUILDROOT_GLIBC if BR2_aarch64 || BR2_aarch64_be \
+		|| BR2_microblaze || BR2_mips64 || BR2_mips64el || BR2_powerpc64
 
 config BR2_TOOLCHAIN_BUILDROOT_UCLIBC
 	bool "uClibc"

@@ -42,11 +42,12 @@ config BR2_TOOLCHAIN_BUILDROOT_UCLIBC
 
 config BR2_TOOLCHAIN_BUILDROOT_EGLIBC
 	bool "eglibc"
-	depends on BR2_arm    || BR2_armeb    || BR2_aarch64 || \
-		   BR2_i386   || BR2_mips     || BR2_mipsel  || \
-		   BR2_mips64 || BR2_mips64el || BR2_powerpc || \
-		   BR2_sh     || BR2_sh64     || BR2_sparc   || \
-		   BR2_x86_64 || BR2_microblaze || BR2_powerpc64
+	depends on BR2_arm        || BR2_armeb    || BR2_aarch64    || \
+		   BR2_aarch64_be || BR2_i386     || BR2_mips       || \
+		   BR2_mipsel     || BR2_mips64   || BR2_mips64el   || \
+		   BR2_powerpc    || BR2_sh       || BR2_sh64       || \
+		   BR2_sparc      || BR2_x86_64   || BR2_microblaze || \
+		   BR2_powerpc64
 	depends on BR2_USE_MMU
 	depends on !BR2_STATIC_LIBS
 	select BR2_TOOLCHAIN_USES_GLIBC

@@ -60,12 +61,12 @@ config BR2_TOOLCHAIN_BUILDROOT_EGLIBC
 
 config BR2_TOOLCHAIN_BUILDROOT_GLIBC
 	bool "glibc"
-	depends on BR2_arm         || BR2_armeb    || BR2_aarch64 || \
-		   BR2_i386        || BR2_mips     || BR2_mipsel  || \
-		   BR2_mips64      || BR2_mips64el || BR2_powerpc || \
-		   BR2_powerpc64   || BR2_powerpc64le || BR2_sh   || \
-		   BR2_sh64        || BR2_sparc    || BR2_x86_64  || \
-		   BR2_microblaze  || BR2_nios2
+	depends on BR2_arm         || BR2_armeb      || BR2_aarch64 || \
+		   BR2_aarch64_be  || BR2_i386       || BR2_mips    || \
+		   BR2_mipsel      || BR2_mips64     || BR2_mips64el|| \
+		   BR2_powerpc     || BR2_powerpc64  || BR2_powerpc64le || \
+		   BR2_sh          || BR2_sh64       || BR2_sparc   || \
+		   BR2_x86_64      || BR2_microblaze || BR2_nios2
 	depends on BR2_USE_MMU
 	depends on !BR2_STATIC_LIBS
 	depends on !BR2_powerpc_SPE
Signature · 1 line
1.8.4.5
author
#3 lore raw

RFC PATCH v2 2/5 aarch64: ilp32: handle special file name

In reply to Zhang Jian (Bamvor)

In aarch64 ilp32, the directory of library is libilp32 and the linker is ld-linux-aarch64_ilp32.so.1 or ld-linux-aarch64_be_ilp32.so.1.

Signed-off-by Zhang Jian(Bamvor) <[email protected]>
---
 Makefile                                           |  9 +++++
 toolchain/helpers.mk                               |  4 +--
 toolchain/toolchain-external/toolchain-external.mk | 41 ++++++++++++++++++++--
 3 files changed, 50 insertions(+), 4 deletions(-)
Makefile +9 -0
index 84402be..0fbb12a 100644
@@ -456,6 +456,15 @@ LIB_SYMLINK = lib64
 else
 LIB_SYMLINK = lib32
 endif
+ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
+# Leave extension for x32 on x86_64 which is libx32 instead of libx32
+ifeq ($(BR2_aarch64), y)
+LIB_SYMLINK = libilp32
+endif
+ifeq ($(BR2_aarch64_be), y)
+LIB_SYMLINK = libilp32
+endif
+endif
 
 $(STAGING_DIR):
 	@mkdir -p $(STAGING_DIR)/bin
toolchain/helpers.mk +2 -2
index 3121da4..ffb5c72 100644
@@ -38,7 +38,7 @@
 #
 # $1: arch specific sysroot directory
 # $2: support libraries directory (can be empty)
-# $3: library directory ('lib' or 'lib64') from which libraries must be copied
+# $3: library directory ('lib', 'lib64' or 'libilp32') from which libraries must be copied
 # $4: library name
 # $5: destination directory of the libary, relative to $(TARGET_DIR)
 #

@@ -140,7 +140,7 @@ copy_toolchain_sysroot = \
 	for i in etc $${ARCH_LIB_DIR} sbin usr usr/$${ARCH_LIB_DIR}; do \
 		if [ -d $${ARCH_SYSROOT_DIR}/$$i ] ; then \
 			rsync -au --chmod=Du+w --exclude 'usr/lib/locale' \
-				--exclude lib --exclude lib32 --exclude lib64 \
+				--exclude lib --exclude lib32 --exclude lib64 --exclude libilp32 \
 				$${ARCH_SYSROOT_DIR}/$$i/ $(STAGING_DIR)/$$i/ ; \
 		fi ; \
 	done ; \
toolchain/toolchain-external/toolchain-external.mk +39 -2

86 lines not on this page · raw message

Signature · 1 line
1.8.4.5
#4 lore raw

RFC PATCH v2 2/5 aarch64: ilp32: handle special file name

Quoted 2 lines · Zhang Jian(Bamvor)

In aarch64 ilp32, the directory of library is libilp32 and the linker is ld-linux-aarch64_ilp32.so.1 or ld-linux-aarch64_be_ilp32.so.1.

There's a couple of issues here, let's see...

Makefile LIB_SYMLINK = lib64 · line 467

Quoted 9 lines
Makefile +9 -0
+ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
+# Leave extension for x32 on x86_64 which is libx32 instead of libx32
+ifeq ($(BR2_aarch64), y)
+LIB_SYMLINK = libilp32
+endif
+ifeq ($(BR2_aarch64_be), y)
+LIB_SYMLINK = libilp32
+endif
+endif

You can simplify this:

ifeq ($(BR2_aarch64)$(BR2_aarch64_be),y)
ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
LIB_SYMLINK = libilp32
endif
endif

aarch64 & aarch64_be won't be defined at the same time so you can condense it in a single ifeq.
Also the comment doesn't apply IMHO, there's nothing related to x86_64 here yet.
Additionally it has to be aarch64 before it can be ilp32 right? And is "ilp32" used for any other architecture? If not you could remove the whole aarch64 clause.

toolchain/toolchain-external/toolchain-external.mk ifeq ($(BR2_TOOLCHAIN_EXTERNAL_MUSL),y) · line 91

Quoted 3 lines
toolchain/toolchain-external/toolchain-external.mk +3 -0
+ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
+LIB_EXTERNAL_LIBS += ld*.so
+endif

Can we focus this a little bit more like it's done for ARM EABIhf instead of just copying ld* blindly?
Otherwise the rest looks ok from a quick look/without having a toolchain to test things.
Regards.

author
#5 lore raw

RFC PATCH v2 2/5 aarch64: ilp32: handle special file name

Quoted 25 lines · Gustavo Zacarias
Quoted 2 lines · Zhang Jian(Bamvor)

In aarch64 ilp32, the directory of library is libilp32 and the linker is ld-linux-aarch64_ilp32.so.1 or ld-linux-aarch64_be_ilp32.so.1.

There's a couple of issues here, let's see...

Makefile LIB_SYMLINK = lib64 · line 467

Quoted 9 lines
Makefile +9 -0
+ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
+# Leave extension for x32 on x86_64 which is libx32 instead of libx32
+ifeq ($(BR2_aarch64), y)
+LIB_SYMLINK = libilp32
+endif
+ifeq ($(BR2_aarch64_be), y)
+LIB_SYMLINK = libilp32
+endif
+endif

You can simplify this:

ifeq ($(BR2_aarch64)$(BR2_aarch64_be),y)
ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
LIB_SYMLINK = libilp32
endif
endif

Quoted 7 lines

aarch64 & aarch64_be won't be defined at the same time so you can condense it in a single ifeq.
Also the comment doesn't apply IMHO, there's nothing related to x86_64 here yet.
Additionally it has to be aarch64 before it can be ilp32 right? And is "ilp32" used for any other architecture? If not you could remove the whole aarch64 clause.

Ilp32 is used in x86_64 too. But the name of ilp32 in x86_64 is x32.

Quoted 7 lines

toolchain/toolchain-external/toolchain-external.mk ifeq ($(BR2_TOOLCHAIN_EXTERNAL_MUSL),y) · line 91

Quoted 4 lines
toolchain/toolchain-external/toolchain-external.mk +3 -0
+ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
+LIB_EXTERNAL_LIBS += ld*.so
+endif

Can we focus this a little bit more like it's done for ARM EABIhf instead of just copying ld* blindly?

Oh, it is ld-VERSION.so in libilp32 directory. The ld-linux-aarch64_ilp32.so.1 is only existed in lib directory. And ld-linux-aarch64_ilp32.so.1 is the only file I need in lib. So, here, I just skip the lib directory.

regards

bamvor

Quoted 5 lines

Otherwise the rest looks ok from a quick look/without having a toolchain to test things.
Regards.

author
#6 lore raw

RFC PATCH v2 2/5 aarch64: ilp32: handle special file name

Quoted 41 lines · Bamvor Jian Zhang
Quoted 25 lines · Gustavo Zacarias
Quoted 2 lines · Zhang Jian(Bamvor)

In aarch64 ilp32, the directory of library is libilp32 and the linker is ld-linux-aarch64_ilp32.so.1 or ld-linux-aarch64_be_ilp32.so.1.

There's a couple of issues here, let's see...

Makefile LIB_SYMLINK = lib64 · line 467

Quoted 9 lines
Makefile +9 -0
+ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
+# Leave extension for x32 on x86_64 which is libx32 instead of libx32
+ifeq ($(BR2_aarch64), y)
+LIB_SYMLINK = libilp32
+endif
+ifeq ($(BR2_aarch64_be), y)
+LIB_SYMLINK = libilp32
+endif
+endif

You can simplify this:

ifeq ($(BR2_aarch64)$(BR2_aarch64_be),y)
ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
LIB_SYMLINK = libilp32
endif
endif

Quoted 7 lines

aarch64 & aarch64_be won't be defined at the same time so you can condense it in a single ifeq.
Also the comment doesn't apply IMHO, there's nothing related to x86_64 here yet.
Additionally it has to be aarch64 before it can be ilp32 right? And is "ilp32" used for any other architecture? If not you could remove the whole aarch64 clause.

Ilp32 is used in x86_64 too. But the name of ilp32 in x86_64 is x32.

Quoted 7 lines

toolchain/toolchain-external/toolchain-external.mk ifeq ($(BR2_TOOLCHAIN_EXTERNAL_MUSL),y) · line 91

Quoted 4 lines
toolchain/toolchain-external/toolchain-external.mk +3 -0
+ifeq ($(BR2_GCC_TARGET_ABI), "ilp32")
+LIB_EXTERNAL_LIBS += ld*.so
+endif

Can we focus this a little bit more like it's done for ARM EABIhf instead of just copying ld* blindly?

Quoted 9 lines

Oh, it is ld-VERSION.so in libilp32 directory. The ld-linux-aarch64_ilp32.so.1 is only existed in lib directory. And ld-linux-aarch64_ilp32.so.1 is the only file I need in lib. So, here, I just skip the lib directory.

regards

bamvor

Quoted 2 lines

Otherwise the rest looks ok from a quick look/without having a toolchain to test things.

Well, you could test it with the toolchain built by linaro ABE. The abe script and the source of linaro gcc is public, but the toolchain binary with ilp32 support is not public.
I contact with linaro guys last month. They told me that linaro will not provide the toolchain binary with ilp32 support until the libilp32 is upstreamed.

regards

bamvor

Quoted 5 lines
Quoted 3 lines

Regards.

author
#7 lore raw

RFC PATCH v2 3/5 aarch64: ilp32: add ilp32 compiler and linker flags

In reply to Zhang Jian (Bamvor)

In aarch64, lp64 is the default ABI. Need pass the special flags if the user want to compile and link ilp32 application.

Signed-off-by Zhang Jian(Bamvor) <[email protected]>
---
 package/Makefile.in | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
package/Makefile.in +9 -1
index 803b162..23f376f 100644
@@ -106,6 +106,14 @@ ifeq ($(BR2_arc)$(BR2_ARC_ATOMIC_EXT),yy)
 TARGET_ABI += -matomic
 endif
 
+ifeq ($(BR2_AARCH64_ILP32)$(BR2_aarch64),yy)
+TARGET_ABI += -mabi=ilp32 -Xlinker -maarch64linux32
+endif
+
+ifeq ($(BR2_AARCH64_ILP32)$(BR2_aarch64_be),yy)
+TARGET_ABI += -mabi=ilp32 -Xlinker -EB -Xlinker -maarch64linux32b
+endif
+
 STAGING_SUBDIR = usr/$(GNU_TARGET_NAME)/sysroot
 STAGING_DIR    = $(HOST_DIR)/$(STAGING_SUBDIR)
 

@@ -142,7 +150,7 @@ endif
 
 TARGET_CFLAGS = $(TARGET_CPPFLAGS) $(TARGET_ABI) $(TARGET_OPTIMIZATION) $(TARGET_DEBUGGING)
 TARGET_CXXFLAGS = $(TARGET_CFLAGS)
-TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS))
+TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS)) $(TARGET_ABI)
 
 ifeq ($(BR2_BINFMT_FLAT),y)
 TARGET_CFLAGS += $(if $($(PKG)_FLAT_STACKSIZE),-Wl$(comma)-elf2flt=-s$($(PKG)_FLAT_STACKSIZE),\
Signature · 1 line
1.8.4.5
#8 lore raw

RFC PATCH v2 3/5 aarch64: ilp32: add ilp32 compiler and linker flags

package/Makefile.in ifeq ($(BR2_arc)$(BR2_ARC_ATOMIC_EXT),yy) · line 115

Quoted 7 lines · Zhang Jian(Bamvor)
package/Makefile.in +7 -0
+ifeq ($(BR2_AARCH64_ILP32)$(BR2_aarch64),yy)
+TARGET_ABI += -mabi=ilp32 -Xlinker -maarch64linux32
+endif
+
+ifeq ($(BR2_AARCH64_ILP32)$(BR2_aarch64_be),yy)
+TARGET_ABI += -mabi=ilp32 -Xlinker -EB -Xlinker -maarch64linux32b
+endif

Ok, but...

package/Makefile.in endif · line 153

Quoted 2 lines
package/Makefile.in +1 -1
-TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS))
+TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS)) $(TARGET_ABI)

...you're throwing -mabi at ld, i don't think ld understands that and would probably break other architectures like PowerPC e500. Regards.

author
#9 lore raw

RFC PATCH v2 3/5 aarch64: ilp32: add ilp32 compiler and linker flags

Quoted 12 lines · Gustavo Zacarias

package/Makefile.in ifeq ($(BR2_arc)$(BR2_ARC_ATOMIC_EXT),yy) · line 115

Quoted 7 lines · Zhang Jian(Bamvor)
package/Makefile.in +7 -0
+ifeq ($(BR2_AARCH64_ILP32)$(BR2_aarch64),yy)
+TARGET_ABI += -mabi=ilp32 -Xlinker -maarch64linux32
+endif
+
+ifeq ($(BR2_AARCH64_ILP32)$(BR2_aarch64_be),yy)
+TARGET_ABI += -mabi=ilp32 -Xlinker -EB -Xlinker -maarch64linux32b
+endif

Ok, but...

Quoted 5 lines

package/Makefile.in endif · line 153

Quoted 2 lines
package/Makefile.in +1 -1
-TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS))
+TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS)) $(TARGET_ABI)

...you're throwing -mabi at ld, i don't think ld understands that and would probably break other architectures like PowerPC e500.

Well, I guess it will only work for aarch64 because the BR2_AARCH64_ILP32. Meanwhile, maybe I only need the "-Xlinker -EB -Xlinker -maarch64linux32b". I will change it in my next version.

regards

bamvor

Quoted 2 lines

Regards.

author
#10 lore raw

RFC PATCH v2 4/5 aarch64: ilp32: add ilp32 build config

In reply to Zhang Jian (Bamvor)

Add ILP32 in menuconfig. And disable the libc and toolchain which does not support ILP32.

Signed-off-by Zhang Jian(Bamvor) <[email protected]>
---
 arch/Config.in.aarch64                 | 35 ++++++++++++++++++++++++++++++++++
 package/gcc/Config.in.host             |  3 ++-
 toolchain/Config.in                    |  2 ++
 toolchain/toolchain-external/Config.in | 20 +++++++++++++++++++
 4 files changed, 59 insertions(+), 1 deletion(-)
arch/Config.in.aarch64 +35 -0
index 9830302..c9434d7 100644
@@ -9,3 +9,38 @@ config BR2_ENDIAN
 config BR2_ARCH_HAS_ATOMICS
 	default y
 
+config BR2_GCC_TARGET_ABI
+	default "" if BR2_AARCH64_LP64
+	default "ilp32" if BR2_AARCH64_ILP32
+
+choice
+	prompt "Target ABI"
+	depends on BR2_aarch64 || BR2_aarch64_be
+	default BR2_AARCH64_LP64
+	help
+	  Application Binary Interface to use. The Application Binary
+	  Interface describes the calling conventions (how arguments
+	  are passed to functions, how the return value is passed, how
+	  system calls are made, etc.).
+
+config BR2_AARCH64_LP64
+	bool "LP64"
+	help
+	  The LP64 is the default ABI in aarch64. It means that
+	  long and pointer is 64bit.
+
+ config BR2_AARCH64_ILP32
+	bool "ILP32"
+	help
+	  ILP32 is a method for running 32bit application on 64bit platform, such
+	  binary is elf32 with aarch64 assembly and is compiled by 64bit compiler.
+	  Refer the following table:
+
+	    \-            |  arm 32bit  | arm64 ILP32 | arm64 LP64
+	  ----------------|-------------|-------------|-------------
+	  instruction set |   armv7-a   |   armv8-a   |   armv8-a
+	  int             |   32bit     |   32bit     |   32bit
+	  long            |   32bit     | **32bit**   |   64bit
+	  pointer         |   32bit     | **32bit**   |   64bit
+
+endchoice
package/gcc/Config.in.host +2 -1
index 1a5281c..b072e4d 100644
@@ -56,7 +56,8 @@ choice
 		bool "gcc 4.8.x"
 		# Broken or unsupported architectures
 		depends on !BR2_microblaze && !BR2_arc \
-			&& !BR2_bfin && !BR2_powerpc64le && !BR2_nios2
+			&& !BR2_bfin && !BR2_powerpc64le && !BR2_nios2 \
+			&& !BR2_AARCH64_ILP32
 		# Broken or unsupported ARM cores
 		depends on !BR2_cortex_a12
 		# Broken or unsupported PPC cores
toolchain/Config.in +2 -0
index efb77f8..c78708d 100644
@@ -31,6 +31,7 @@ config BR2_TOOLCHAIN_USES_MUSL
 	select BR2_TOOLCHAIN_HAS_THREADS
 	select BR2_TOOLCHAIN_HAS_THREADS_DEBUG
 	select BR2_TOOLCHAIN_HAS_THREADS_NPTL
+	depends on !BR2_AARCH64_ILP32
 
 choice
 	prompt "Toolchain type"

@@ -44,6 +45,7 @@ choice
 config BR2_TOOLCHAIN_BUILDROOT
 	bool "Buildroot toolchain"
 	depends on !BR2_bfin
+	depends on !BR2_AARCH64_ILP32
 	select BR2_TOOLCHAIN_HAS_SHADOW_PASSWORDS
 
 config BR2_TOOLCHAIN_EXTERNAL
toolchain/toolchain-external/Config.in +20 -0
index 8b0f09b..48082b0 100644
@@ -835,6 +835,7 @@ config BR2_TOOLCHAIN_EXTERNAL_LINARO_AARCH64
 	depends on BR2_aarch64
 	depends on BR2_HOSTARCH = "x86_64" || BR2_HOSTARCH = "x86"
 	depends on !BR2_STATIC_LIBS
+	depends on !BR2_AARCH64_ILP32
 	select BR2_TOOLCHAIN_EXTERNAL_GLIBC
 	select BR2_INSTALL_LIBSTDCPP
 	select BR2_HOSTARCH_NEEDS_IA32_LIBS

@@ -849,6 +850,7 @@ config BR2_TOOLCHAIN_EXTERNAL_CODESOURCERY_AARCH64
 	depends on BR2_aarch64
 	depends on BR2_HOSTARCH = "x86_64" || BR2_HOSTARCH = "x86"
 	depends on !BR2_STATIC_LIBS
+	depends on !BR2_AARCH64_ILP32
 	select BR2_TOOLCHAIN_EXTERNAL_GLIBC
 	select BR2_INSTALL_LIBSTDCPP
 	select BR2_HOSTARCH_NEEDS_IA32_LIBS

@@ -1043,69 +1045,86 @@ config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_16
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_15
 	bool "3.15.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_15
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_14
 	bool "3.14.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_14
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_13
 	bool "3.13.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_13
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_12
 	bool "3.12.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_12
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_11
 	bool "3.11.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_11
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_10
 	bool "3.10.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_9
 	bool "3.9.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_9
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_8
 	bool "3.8.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_8
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_7
 	bool "3.7.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_7
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_6
 	bool "3.6.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_6
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_5
 	bool "3.5.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_5
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_4
 	bool "3.4.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_4
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_3
 	bool "3.3.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_3
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_2
 	bool "3.2.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_2
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_1
 	bool "3.1.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_1
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_0
 	bool "3.0.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_0
+	depends on !BR2_AARCH64_ILP32
 
 config BR2_TOOLCHAIN_EXTERNAL_HEADERS_REALLY_OLD
 	bool "2.6.x"
+	depends on !BR2_AARCH64_ILP32
 
 endchoice
 

@@ -1116,6 +1135,7 @@ choice
 config BR2_TOOLCHAIN_EXTERNAL_CUSTOM_UCLIBC
 	bool "uClibc"
 	select BR2_TOOLCHAIN_EXTERNAL_UCLIBC
+	depends on !BR2_AARCH64_ILP32
 	# For the time being, we assume that all custom external
 	# toolchains have shadow password support.
 	select BR2_TOOLCHAIN_HAS_SHADOW_PASSWORDS
Signature · 1 line
1.8.4.5
#11 lore raw

RFC PATCH v2 4/5 aarch64: ilp32: add ilp32 build config

arch/Config.in.aarch64 config BR2_ENDIAN · line 14

Quoted 3 lines · Zhang Jian(Bamvor)
arch/Config.in.aarch64 +3 -0
+config BR2_GCC_TARGET_ABI
+	default "" if BR2_AARCH64_LP64
+	default "ilp32" if BR2_AARCH64_ILP32

Even though it's unused we like giving things a name, so it would be "lp64" for the pure 64-bit ABI.
Also like i said before having a toolchain to test all this would be nice. Regards.

author
#12 lore raw

RFC PATCH v2 4/5 aarch64: ilp32: add ilp32 build config

Quoted 10 lines · Gustavo Zacarias
Quoted 3 lines · Zhang Jian(Bamvor)

arch/Config.in.aarch64 config BR2_ENDIAN · line 14

Quoted 3 lines
arch/Config.in.aarch64 +3 -0
+config BR2_GCC_TARGET_ABI
+	default "" if BR2_AARCH64_LP64
+	default "ilp32" if BR2_AARCH64_ILP32

Even though it's unused we like giving things a name, so it would be "lp64" for the pure 64-bit ABI.
Also like i said before having a toolchain to test all this would be nice. Regards.

I think I need to leave it as empty(""), because I want to follow your suggection in March[1].
Please correct, if I misunderstand you.

regards

bamvor

[1] http://lists.busybox.net/pipermail/buildroot/2015-March/122332.html

author
#13 lore raw

RFC PATCH v2 5/5 aarch64: ilp32 defconfig examples

In reply to Zhang Jian (Bamvor)

DO NOT APPLY.

Test aarch64 lp64 through qemu_aarch64_virt_defconfig. Test aarch64 ilp32, aarch64_be lp64, aarch64_be ilp32 through the following config.

Signed-off-by Zhang Jian(Bamvor) <[email protected]>
---
 configs/aarch64_be_defconfig       | 2 ++
 configs/aarch64_be_ilp32_defconfig | 8 ++++++++
 configs/aarch64_ilp32_defconfig    | 8 ++++++++
 3 files changed, 18 insertions(+)
 create mode 100644 configs/aarch64_be_defconfig
 create mode 100644 configs/aarch64_be_ilp32_defconfig
 create mode 100644 configs/aarch64_ilp32_defconfig
configs/aarch64_be_defconfig new file +2 -0
new file mode 100644
index 0000000..6995953
@@ -0,0 +1,2 @@
+# Architecture
+BR2_aarch64_be=y
configs/aarch64_be_ilp32_defconfig new file +8 -0
new file mode 100644
index 0000000..6a2848a
@@ -0,0 +1,8 @@
+# Architecture
+BR2_aarch64_be=y
+BR2_AARCH64_ILP32=y
+BR2_TOOLCHAIN_EXTERNAL_PATH="/path/to/your/toolchain"
+BR2_TOOLCHAIN_EXTERNAL_CUSTOM_PREFIX="$(ARCH)-linux-gnu"
+BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_16=y
+BR2_TOOLCHAIN_EXTERNAL_INET_RPC=y
+BR2_TOOLCHAIN_EXTERNAL_CXX=y
configs/aarch64_ilp32_defconfig new file +8 -0
new file mode 100644
index 0000000..2956b05
@@ -0,0 +1,8 @@
+# Architecture
+BR2_aarch64=y
+BR2_AARCH64_ILP32=y
+BR2_TOOLCHAIN_EXTERNAL_PATH="/path/to/your/toolchain"
+BR2_TOOLCHAIN_EXTERNAL_CUSTOM_PREFIX="$(ARCH)-linux-gnu"
+BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_16=y
+BR2_TOOLCHAIN_EXTERNAL_INET_RPC=y
+BR2_TOOLCHAIN_EXTERNAL_CXX=y
Signature · 1 line
1.8.4.5
author
#14 lore raw

v2 cover Add ILP32 support in aarch64

In reply to Zhang Jian (Bamvor)

On 2015/3/18 17:49, Zhang Jian(Bamvor) wrote:
Ping.
It seems that no response in recent four weeks.

bamvor

Quoted 73 lines

This is second version of my patches. This previous version is here[1]. The previous discussion, Gustavo agree that only external toolchain is in consideration at this time. I will try to work on the buildroot toolchain after current series patch is upstreamed.

ILP32 is very useful when the user want to migrate from arm 32bit to 64bit with minimal risk. There is no code changes and almost no footprint changes after migration. ILP32 could get the better performance compare with arm 32bit (use 64bit register and instruction instead of 32bit one) and aarch64 LP64 (aarch64 default ABI).

Our test show that the performance of ILP32 is roughly 10% better than arm64 LP64 while the footprint is 86% of LP64. Because of these, It is useful for both embedded and enterprise system.

Here is the details definition of ILP32:
ILP32 is elf32 with aarch64 assembly and is compiled by 64bit compiler. Refer the following table:

  \-            |  arm 32bit  | arm64 ILP32 | arm64 LP64
----------------|-------------|-------------|-------------
instruction set |   armv7-a   |   armv8-a   |   armv8-a
int             |   32bit     |   32bit     |   32bit
long            |   32bit     | **32bit**   |   64bit
pointer         |   32bit     | **32bit**   |   64bit

LP64 is the default ABI on arm64(Implies -mabi=lp64 while compiling), and the kernel remains in LP64 no matter ILP32 enables or not.

These series patches introduce the big endian support in aarch64 and then add ILP32 special filename and menuconfig step by step.

The test of build is based on linaro kernel [2] and toolchain built by linaro ABE environment[3], anyone could built this toolchain through the simpile abe script.

This is my first time I try to contribute the buildroot, feedback is very appreciated. Sorry if there are some coding style issues.

changes since v1

1.  avoid mabi issue in gcc 4.8 while build aarch64 lp64.
2.  change default libc, toolchain for ilp32 build.
3.  others changes suggested by Gustavo.

[1] http://lists.busybox.net/pipermail/buildroot/2015-March/122115.html
[2] https://git.linaro.org/kernel/linux-linaro-tracking.git
[3] https://wiki.linaro.org/ABE

Zhang Jian(Bamvor) (5):
aarch64: add big endian(aarch64_be) support
aarch64: ilp32: handle special file name
aarch64: ilp32: add ilp32 compiler and linker flags
aarch64: ilp32: add ilp32 build config
aarch64: ilp32 defconfig examples

 Makefile                                           | 11 +++++-
 arch/Config.in                                     | 12 +++++--
 arch/Config.in.aarch64                             | 40 ++++++++++++++++++++-
 configs/aarch64_be_defconfig                       |  2 ++
 configs/aarch64_be_ilp32_defconfig                 |  8 +++++
 configs/aarch64_ilp32_defconfig                    |  8 +++++
 package/Makefile.in                                | 10 +++++-
 package/gcc/Config.in.host                         |  3 +-
 toolchain/Config.in                                |  2 ++
 toolchain/helpers.mk                               |  4 +--
 toolchain/toolchain-buildroot/Config.in            | 27 +++++++-------
 toolchain/toolchain-external/Config.in             | 20 +++++++++++
 toolchain/toolchain-external/toolchain-external.mk | 41 ++++++++++++++++++++--
 13 files changed, 165 insertions(+), 23 deletions(-)
 create mode 100644 configs/aarch64_be_defconfig
 create mode 100644 configs/aarch64_be_ilp32_defconfig
 create mode 100644 configs/aarch64_ilp32_defconfig
#15 lore raw

v2 cover Add ILP32 support in aarch64

In reply to Zhang Jian (Bamvor)

Dear Zhang Jian(Bamvor),

Quoted 2 lines · Zhang Jian(Bamvor)

Zhang Jian(Bamvor) (5):
aarch64: add big endian(aarch64_be) support

I've now applied this patch. However it is not complete enough: you need to audit all the places where BR2_aarch64 is used in Buildroot, and see whether adding BR2_aarch64_be is needed. For example, in package/binutils/Config.in.host:

        config BR2_BINUTILS_VERSION_2_23_2
                depends on !BR2_aarch64 && !BR2_microblaze && \
                           !BR2_powerpc64le && !BR2_nios2
                bool "binutils 2.23.2"

You quite probably want to add !BR2_aarch64_be here as well.

Quoted 4 lines

aarch64: ilp32: handle special file name
aarch64: ilp32: add ilp32 compiler and linker flags
aarch64: ilp32: add ilp32 build config
aarch64: ilp32 defconfig examples

For those patches, you had some comments. A while ago, when I sent you a reminder about those patches, you said you would resend an updated version, but this didn't happen. For now, we marked those patches as "Changes Requested" in patchwork. Do not hesitate to resend a new version.

Thanks a lot!

Thomas

Signature · 3 lines
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
author
#16 lore raw

v2 cover Add ILP32 support in aarch64

Hi,

Quoted 24 lines · Thomas Petazzoni

Dear Zhang Jian(Bamvor),

Quoted 2 lines · Zhang Jian(Bamvor)

Zhang Jian(Bamvor) (5):
aarch64: add big endian(aarch64_be) support

I've now applied this patch. However it is not complete enough: you need to audit all the places where BR2_aarch64 is used in Buildroot, and see whether adding BR2_aarch64_be is needed. For example, in package/binutils/Config.in.host:

         config BR2_BINUTILS_VERSION_2_23_2
                 depends on !BR2_aarch64 && !BR2_microblaze && \
                            !BR2_powerpc64le && !BR2_nios2
                 bool "binutils 2.23.2"

You quite probably want to add !BR2_aarch64_be here as well.

Quoted 4 lines

aarch64: ilp32: handle special file name
aarch64: ilp32: add ilp32 compiler and linker flags
aarch64: ilp32: add ilp32 build config
aarch64: ilp32 defconfig examples

Quoted 5 lines

For those patches, you had some comments. A while ago, when I sent you a reminder about those patches, you said you would resend an updated version, but this didn't happen. For now, we marked those patches as "Changes Requested" in patchwork. Do not hesitate to resend a new version.

Sorry for not sending the updated patches. I will do it in this week.

bamvor

Quoted 5 lines

Thanks a lot!

Thomas