[U-Boot] Compiling for ARMv7-a
Hi,
I am trying to build the u-boot for ARM Cortex-A8 (OMAP3).
By default the code is built for ARMv5. So, I made this change in cpu/arm_cortexa8/config.mk:
# Make ARMv5 to allow more compilers to work, even though its v7a. -PLATFORM_CPPFLAGS += -march=armv5 +PLATFORM_CPPFLAGS += -march=armv7-a
But when I run make, command-line looks like:
arm-none-linux-gnueabi-gcc -g -Os -fno-strict-aliasing -fno-common -ffixed-r8 -msoft-float -fno-strict-aliasing -fno-common -ffixed-r8 -msoft-float -D__KERNEL__ -DTEXT_BASE=0x80e80000 -I/home/premi/u-boot/include -fno-builtin -ffreestanding -nostdinc -isystem /opt/codesourcery/lib/gcc/arm-none-linux- gnueabi/4.3.2/include -pipe -DCONFIG_ARM -D__ARM__ -march=armv7-a -mno-thumb-interwork -march=armv5 -mno-thumb-interwork -Wall -Wstrict-prototypes -fno-stack-protector -c -o date.o date.c
Notice that -march=armv7-a is followed by -march=armv5.
Which option will take precedence? What is required to make sure both are same. My attempt at this change was not successful:
omap3_evm_config : unconfig - @$(MKCONFIG) $(@:_config=) arm arm_cortexa8 evm omap3 omap3 + @$(MKCONFIG) $(@:_config=) arm_cortexa8 arm_cortexa8 evm omap3 omap3
Also, many other options are duplicate on the command-line. May be okay, but is there a way to remove this duplication?
Best regards, Sanjeev
On 21:27 Thu 02 Apr , Premi, Sanjeev wrote:
Hi,
I am trying to build the u-boot for ARM Cortex-A8 (OMAP3).
By default the code is built for ARMv5. So, I made this change in cpu/arm_cortexa8/config.mk:
# Make ARMv5 to allow more compilers to work, even though its v7a. -PLATFORM_CPPFLAGS += -march=armv5 +PLATFORM_CPPFLAGS += -march=armv7-a
you do not need to modify any thing the current tree support omap3
we just not use the armv7-a optimization to be compatible with the maximum of toolchains
maybe you could explain us why you need it?
Best Regards, J.
-----Original Message----- From: Jean-Christophe PLAGNIOL-VILLARD [mailto:plagnioj@jcrosoft.com] Sent: Saturday, April 04, 2009 9:41 PM To: Premi, Sanjeev Cc: u-boot@lists.denx.de Subject: Re: [U-Boot] Compiling for ARMv7-a
On 21:27 Thu 02 Apr , Premi, Sanjeev wrote:
Hi,
I am trying to build the u-boot for ARM Cortex-A8 (OMAP3).
By default the code is built for ARMv5. So, I made this change in cpu/arm_cortexa8/config.mk:
# Make ARMv5 to allow more compilers to work, even though its v7a. -PLATFORM_CPPFLAGS += -march=armv5 +PLATFORM_CPPFLAGS += -march=armv7-a
you do not need to modify any thing the current tree support omap3
we just not use the armv7-a optimization to be compatible with the maximum of toolchains
maybe you could explain us why you need it?
[sp] Only as an exercise to see if compiling for ARM v7 provides any better performance - speed and/or power-consumption.
Best Regards, J.
Dear "Premi, Sanjeev",
In message B85A65D85D7EB246BE421B3FB0FBB59301CC6FBE61@dbde02.ent.ti.com you wrote:
maybe you could explain us why you need it?
[sp] Only as an exercise to see if compiling for ARM v7 provides any better performance - speed and/or power-consumption.
...both of which are most probably irrelevant in a boot loader, thatunder normal operating conditions has a total execution time of just a few hundred milliseconds per power-cycle.
Best regards,
Wolfgang Denk
-----Original Message----- From: Wolfgang Denk [mailto:wd@denx.de] Sent: Monday, April 06, 2009 1:29 PM To: Premi, Sanjeev Cc: Jean-Christophe PLAGNIOL-VILLARD; u-boot@lists.denx.de Subject: Re: [U-Boot] Compiling for ARMv7-a
Dear "Premi, Sanjeev",
In message B85A65D85D7EB246BE421B3FB0FBB59301CC6FBE61@dbde02.ent.ti.com you wrote:
maybe you could explain us why you need it?
[sp] Only as an exercise to see if compiling for ARM v7 provides any better performance - speed and/or power-consumption.
...both of which are most probably irrelevant in a boot loader, thatunder normal operating conditions has a total execution time of just a few hundred milliseconds per power-cycle.
[sp] No, it was not for measuring u-boot but for a small application that I wanted to compare for power consumption. It is probably easier to play with caches, MMU, etc. in the u-boot than in Linux kernel.
Application is merely a calculate-wait-calculate kind of loop.
~sanjeev
Best regards,
Wolfgang Denk
-- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de Just because your doctor has a name for your condition doesn't mean he knows what it is.
participants (3)
-
Jean-Christophe PLAGNIOL-VILLARD -
Premi, Sanjeev -
Wolfgang Denk