Commit 8e55f03a authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Peter Korsgaard
Browse files

Clarify MIPS ABIs support 

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:

 * Add separate mips64/mips64el top-level architectures.

 * 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: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: default avatarPeter Korsgaard <jacmet@sunsite.dk>
parent a9df5048

package/Makefile.in

+1 −1
Original line number Diff line number Diff line
@@ -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

target/Config.in.arch

+35 −25
Original line number Diff line number Diff line
@@ -83,6 +83,22 @@ config BR2_mipsel 
	  http://www.mips.com/

	  http://en.wikipedia.org/wiki/MIPS_Technologies



config BR2_mips64

	bool "MIPS64 (big endian)"

	select BR2_ARCH_IS_64

	help

	  MIPS is a RISC microprocessor from MIPS Technologies. Big endian.

	  http://www.mips.com/

	  http://en.wikipedia.org/wiki/MIPS_Technologies



config BR2_mips64el

	bool "MIPS64 (little endian)"

	select BR2_ARCH_IS_64

	help

	  MIPS is a RISC microprocessor from MIPS Technologies. Big endian.

	  http://www.mips.com/

	  http://en.wikipedia.org/wiki/MIPS_Technologies



config BR2_powerpc

	bool "PowerPC"

	help
@@ -237,9 +253,10 @@ endchoice 


choice

	prompt "Target Architecture Variant"

	depends on BR2_mips || BR2_mipsel

	depends on BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el

	default BR2_mips_3 if BR2_mips

	default BR2_mips_1 if BR2_mipsel

	default BR2_mips_64 if BR2_mips64 || BR2_mips64el

	help

	  Specific CPU variant to use
@@ -248,49 +265,43 @@ choice 


config BR2_mips_1

	bool "mips I (generic)"

	depends on !BR2_ARCH_IS_64

config BR2_mips_2

	bool "mips II"

	depends on !BR2_ARCH_IS_64

config BR2_mips_3

	bool "mips III"

config BR2_mips_4

	bool "mips IV"

config BR2_mips_32

	bool "mips 32"

	depends on !BR2_ARCH_IS_64

config BR2_mips_32r2

	bool "mips 32r2"

	depends on !BR2_ARCH_IS_64

config BR2_mips_64

	bool "mips 64"

config BR2_mips_64r2

	bool "mips 64r2"

config BR2_mips_16

	bool "mips 16"

endchoice





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

	depends on BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el

	default BR2_MIPS_OABI32 if !BR2_ARCH_IS_64

	default BR2_MIPS_NABI32 if BR2_ARCH_IS_64

	help

	  Application Binary Interface to use



config BR2_MIPS_OABI32

	bool "o32"

config BR2_MIPS_ABI32

config BR2_MIPS_NABI32

	bool "n32"

	depends on BR2_mips_3 || BR2_mips_4 || BR2_mips_64 || BR2_mips_64r2 || BR2_mips_16

config BR2_MIPS_ABI64

	depends on BR2_ARCH_IS_64

config BR2_MIPS_NABI64

	bool "n64"

	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.

	depends on BR2_ARCH_IS_64

endchoice



choice
@@ -667,6 +678,8 @@ config BR2_ARCH 
	default "microblaze"	if BR2_microblaze

	default "mips"		if BR2_mips

	default "mipsel"	if BR2_mipsel

	default "mips64"	if BR2_mips64

	default "mips64el"	if BR2_mips64el

	default "powerpc"	if BR2_powerpc

	default "sh2"		if BR2_sh2

	default "sh2a"		if BR2_sh2a
@@ -683,10 +696,10 @@ config BR2_ARCH 


config BR2_ENDIAN

	string

	default "LITTLE" if BR2_arm || BR2_bfin || BR2_i386 || BR2_mipsel || \

	default "LITTLE" if BR2_arm || BR2_bfin || BR2_i386 || BR2_mipsel || BR2_mips64el || \

			    BR2_sh3 || BR2_sh4 || BR2_sh4a || BR2_x86_64 || BR2_sh64 || \

			    BR2_microblazeel

	default "BIG"    if BR2_armeb || BR2_avr32 || BR2_m68k || BR2_mips || \

	default "BIG"    if BR2_armeb || BR2_avr32 || BR2_m68k || BR2_mips || BR2_mips64 || \

			    BR2_powerpc || BR2_sh2 || BR2_sh2a || \

			    BR2_sh3eb || BR2_sh4eb || BR2_sh4aeb || BR2_sparc || \

			    BR2_microblazebe
@@ -754,7 +767,6 @@ config BR2_GCC_TARGET_TUNE 
	default mips32r2	if BR2_mips_32r2

	default mips64		if BR2_mips_64

	default mips64r2	if BR2_mips_64r2

	default mips16		if BR2_mips_16

	default 401		if BR2_powerpc_401

	default 403		if BR2_powerpc_403

	default 405		if BR2_powerpc_405
@@ -859,10 +871,8 @@ config BR2_GCC_TARGET_ABI 
	default apcs-gnu	if BR2_ARM_OABI

	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 altivec		if BR2_powerpc && BR2_PPC_ABI_altivec

	default no-altivec	if BR2_powerpc && BR2_PPC_ABI_no-altivec

	default spe		if BR2_powerpc && BR2_PPC_ABI_spe

toolchain/uClibc/uclibc.mk

+3 −4
Original line number Diff line number Diff line
@@ -37,7 +37,6 @@ UCLIBC_TARGET_ARCH:=$(shell $(SHELL) -c "echo $(ARCH) | sed \ 
		-e 's/v850.*/v850/g' \

		-e 's/sh[234].*/sh/' \

		-e 's/mips.*/mips/' \

		-e 's/mipsel.*/mips/' \

		-e 's/cris.*/cris/' \

		-e 's/xtensa.*/xtensa/' \

")
@@ -142,13 +141,13 @@ 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)