[Buildroot] [PATCH] Clarify MIPS ABIs support
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Wed Jul 25 16:29:43 UTC 2012
Hello Gustavo,
If you could have a look at the below patch, and provide your comments
or Acked-by, it would be great.
Thanks a lot!
Thomas
Le Tue, 24 Jul 2012 22:47:08 +0200,
Thomas Petazzoni <thomas.petazzoni at free-electrons.com> a écrit :
> Practically speaking, MIPS has three useful ABIs:
>
> * o32 is for 32-bits CPUs, or 64-bit CPUs running only a 32-bit subset
> of the instruction set.
> * n32 is for 64-bits CPUs only. It has 32-bits pointers and long
> integers.
> * n64 is for 64-bits CPUs only. It has 64-bits pointers and long
> integers.
>
> See http://www.linux-mips.org/wiki/MIPS_ABI_History and
> http://www.linux-mips.org/wiki/WhatsWrongWithO32N32N64 for more
> details.
>
> So, this commit reworks the Buildroot MIPS support by:
>
> * Renaming the n32 ABI option to BR2_MIPS_NABI32, for consistency
> with BR2_MIPS_OABI32.
>
> * Renaming the n64 ABI option to BR2_MIPS_NABI64, for consistency
> with BR2_MIPS_OABI32.
>
> * Make the n32 and n64 ABI selections select the BR2_ARCH_IS_64,
> since those ABIs are valid on 64-bits CPUs only.
>
> * Removing the o64 ABI, which is practicaly never used.
>
> * Removing the "none" ABI, which really doesn't make sense.
>
> * Introduce the mips64 and mips64el architecture names when a 64-bits
> MIPS ABI is choosen. This will fix build issue like
> http://autobuild.buildroot.org/results/9b8c5ea86c953a89e85e7b67e9221de41773f652/build-end.log
> where gmp was confused by the fact of having a 32 bits architecture
> (detected by the mips- architecture part of the tuple) but 64 bits
> integer size when compiling.
>
> * Adjust the uclibc.mk logic to support the new mips64/mips64el
> architecture names, and take into account the renaming of the ABI
> options.
>
> This has been build tested by generating Buildroot toolchains and
> compiling a few packages for MIPS o32, MIPS n32 and MIPS n64.
>
> This work is originally based on prior work done by Gustavo Zacarias.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
> package/Makefile.in | 2 +-
> target/Config.in.arch | 28 +++++++++++-----------------
> toolchain/uClibc/uclibc.mk | 9 ++++++---
> 3 files changed, 18 insertions(+), 21 deletions(-)
>
> diff --git a/package/Makefile.in b/package/Makefile.in
> index 6fad224..21b8634 100644
> --- a/package/Makefile.in
> +++ b/package/Makefile.in
> @@ -87,7 +87,7 @@ endif
>
> TARGET_CFLAGS=$(TARGET_ABI) $(TARGET_OPTIMIZATION) $(TARGET_DEBUGGING)
>
> -ifeq ($(findstring yy,$(BR2_mips)$(BR2_MIPS_ABI64)),yy)
> +ifeq ($(findstring yy,$(BR2_mips)$(BR2_MIPS_NABI64)),yy)
> TARGET_CFLAGS+=-fno-pic -mno-abicalls
> endif
>
> diff --git a/target/Config.in.arch b/target/Config.in.arch
> index e7aec56..0ef59ef 100644
> --- a/target/Config.in.arch
> +++ b/target/Config.in.arch
> @@ -271,26 +271,20 @@ choice
> prompt "Target ABI"
> depends on BR2_mips || BR2_mipsel
> default BR2_MIPS_OABI32 if BR_mips_32 || BR_mips_32r2
> - default BR2_MIPS_ABI32 if BR_mips_64 || BR_mips_64r2
> + default BR2_MIPS_NABI32 if BR_mips_64 || BR_mips_64r2
> help
> Application Binary Interface to use
>
> config BR2_MIPS_OABI32
> bool "o32"
> -config BR2_MIPS_ABI32
> +config BR2_MIPS_NABI32
> bool "n32"
> + select BR2_ARCH_IS_64
> depends on BR2_mips_3 || BR2_mips_4 || BR2_mips_64 || BR2_mips_64r2 || BR2_mips_16
> -config BR2_MIPS_ABI64
> +config BR2_MIPS_NABI64
> bool "n64"
> + select BR2_ARCH_IS_64
> depends on BR2_mips_3 || BR2_mips_4 || BR2_mips_64 || BR2_mips_64r2 || BR2_mips_16
> -config BR2_MIPS_OABI64
> - bool "o64"
> - depends on BR2_mips_3 || BR2_mips_4 || BR2_mips_64 || BR2_mips_64r2 || BR2_mips_16
> -config BR2_MIPS_ABI_none
> - bool "unspecified"
> - depends on BR2_mips_16
> - help
> - Unspecified ABI leaves ABI selection blank.
> endchoice
>
> choice
> @@ -688,8 +682,10 @@ config BR2_ARCH
> default "i686" if BR2_x86_athlon_4
> default "m68k" if BR2_m68k
> default "microblaze" if BR2_microblaze
> - default "mips" if BR2_mips
> - default "mipsel" if BR2_mipsel
> + default "mips" if BR2_mips && !BR2_ARCH_IS_64
> + default "mipsel" if BR2_mipsel && !BR2_ARCH_IS_64
> + default "mips64" if BR2_mips && BR2_ARCH_IS_64
> + default "mips64el" if BR2_mipsel && BR2_ARCH_IS_64
> default "powerpc" if BR2_powerpc
> default "sh2" if BR2_sh2
> default "sh2a" if BR2_sh2a
> @@ -904,10 +900,8 @@ config BR2_GCC_TARGET_ABI
> default aapcs if BR2_arm_dunno
> default aapcs-linux if BR2_ARM_EABI
> default 32 if BR2_MIPS_OABI32
> - default n32 if BR2_MIPS_ABI32
> - default eabi if BR2_MIPS_EABI
> - default o64 if BR2_MIPS_OABI64
> - default 64 if BR2_MIPS_ABI64
> + default n32 if BR2_MIPS_NABI32
> + default 64 if BR2_MIPS_NABI64
> default mmixware if BR2_mmix && BR2_MMIX_ABI_native
> default gnu if BR2_mmix && !BR2_MMIX_ABI_native
> default altivec if BR2_powerpc && BR2_PPC_ABI_altivec
> diff --git a/toolchain/uClibc/uclibc.mk b/toolchain/uClibc/uclibc.mk
> index 9d0b6db..aff0a60 100644
> --- a/toolchain/uClibc/uclibc.mk
> +++ b/toolchain/uClibc/uclibc.mk
> @@ -38,6 +38,7 @@ UCLIBC_TARGET_ARCH:=$(shell $(SHELL) -c "echo $(ARCH) | sed \
> -e 's/sh[234].*/sh/' \
> -e 's/mips.*/mips/' \
> -e 's/mipsel.*/mips/' \
> + -e 's/mips64el.*/mips/' \
> -e 's/cris.*/cris/' \
> -e 's/xtensa.*/xtensa/' \
> ")
> @@ -45,6 +46,8 @@ UCLIBC_TARGET_ARCH:=$(shell $(SHELL) -c "echo $(ARCH) | sed \
> UCLIBC_TARGET_ENDIAN:=$(shell $(SHELL) -c "echo $(ARCH) | sed \
> -e 's/armeb/BIG/' \
> -e 's/arm/LITTLE/' \
> + -e 's/mips64el/LITTLE/' \
> + -e 's/mips64/BIG/' \
> -e 's/mipsel/LITTLE/' \
> -e 's/mips/BIG/' \
> -e 's/sh.*eb/BIG/' \
> @@ -155,13 +158,13 @@ ifeq ($(UCLIBC_TARGET_ARCH),mips)
> /bin/echo "# CONFIG_MIPS_ISA_MIPS32R2 is not set"; \
> /bin/echo "# CONFIG_MIPS_ISA_MIPS64 is not set"; \
> ) >> $(UCLIBC_DIR)/.oldconfig
> -ifeq ($(BR2_MIPS_OABI),y)
> +ifeq ($(BR2_MIPS_OABI32),y)
> $(SED) 's/.*\(CONFIG_MIPS_O32_ABI\).*/\1=y/' $(UCLIBC_DIR)/.oldconfig
> endif
> -ifeq ($(BR2_MIPS_ABI32),y)
> +ifeq ($(BR2_MIPS_NABI32),y)
> $(SED) 's/.*\(CONFIG_MIPS_N32_ABI\).*/\1=y/' $(UCLIBC_DIR)/.oldconfig
> endif
> -ifeq ($(BR2_MIPS_ABI64),y)
> +ifeq ($(BR2_MIPS_NABI64),y)
> $(SED) 's/.*\(CONFIG_MIPS_N64_ABI\).*/\1=y/' $(UCLIBC_DIR)/.oldconfig
> endif
> ifeq ($(BR2_mips_1),y)
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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