[U-Boot] [PATCH v2] arm: build arch memset/memcpy in Thumb2 mode

Wed Dec 3 18:04:39 CET 2014

On 2014-12-03 16:44, Bill Pringlemeir wrote:
> I tested these changes on several compilers and binutils.  4.3.3, 4.6.3,
> 4.7.2, 4.8.2 and 4.9.2 gcc with binutils 2.19, 2.21-24 in both THUMB and
> ARM on the Vybrid.  It seem we must have an image <= 224kB which is the
> IRAM bank0 size - 0x8000 of u-boot base; u-boot since v2014.04 will not
> boot for me as the QSPI seemed to take it over this boundary.
> 
> The attached patches are meant to be attached as they aren't meant to be
> taken by patchworks, etc but just to show the small changes I made to
> minimize the image to less than 224kB.
> 
> [build script]
> # File sizes similar because of 'mkimage' padding+hdr for 'imx'.
> # 2nd size is for the 'thumb2' builds.
> set -e
> 
> ## (Sourcery CodeBench Lite 2012.03-56) 4.6.3
> ## (Sourcery CodeBench Lite 2012.03-56) 2.21.53.20110905
> # 227092 Dec  1 15:20 u-boot.imx
> # 173844 Dec  1 15:36 u-boot.imx
> export PATH=$PATH:$HOME/x-tools/arm-2012.03/bin
> 
> ## 4.7.4 20130913 (release) [ARM/embedded-4_7-branch revision 202601]
> ## GNU assembler (GNU Binutils) 2.23.2
> # 222996 Dec  1 15:19 u-boot.imx
> # 173844 Dec  1 15:35 u-boot.imx
> #export PATH=$PATH:$HOME/x-tools/arm-2013.q3/bin
> 
> ## (crosstool-NG hg+default-9838aecd6340) 4.8.2
> ## (GNU Binutils) 2.23.2
> # 222996 Dec  1 15:18 u-boot.imx
> # 173844 Dec  1 15:34 u-boot.imx
> #export PATH=$PATH:$HOME/x-tools/arm-none-eabi/bin
> 
> ## (Sourcery G++ Lite 2009q1-161) 4.3.3
> ## (Sourcery G++ Lite 2009q1-161) 2.19.51.20090205
> # 218900 Dec  1 15:17 u-boot.imx - no CONFIG_SYS_LONGHELP
> # GCC does not produce working THUMB binaries.
> #export PATH=$PATH:/opt/arm-2009q1/bin
> NAME=arm-none-eabi-
> 
> ## (crosstool-NG 1.20.0) 4.9.2
> ## (crosstool-NG 1.20.0) 2.24
> # 222996 Dec  1 15:21 u-boot.imx
> # 173844 Dec  1 15:32 u-boot.imx
> #export PATH=$PATH:$HOME/x-tools/arm-none-linux-gnueabi-vybrid-4.9.2/bin/
> 
> ## (crosstool-NG hg+default-2a773bd38e71) 4.7.3
> ## (crosstool-NG hg+default-2a773bd38e71) 2.22
> # 222996 Dec  1 15:22 u-boot.imx
> # 173844 Dec  1 15:31 u-boot.imx
> #export PATH=$PATH:$HOME/x-tools/arm-none-linux-gnueabi-4.7.2/bin
> 
> ## (crosstool-NG hg+-c7fa97debb36) 4.6.3
> ## (crosstool-NG hg+-c7fa97debb36) 2.21.1
> # 227092 Dec  1 15:24 u-boot.imx
> # 173844 Dec  1 15:30 u-boot.imx
> #export PATH=$PATH:$HOME/x-tools/arm-none-linux-gnueabi.gcc4.6.3/bin
> #NAME=arm-none-linux-gnueabi-
> 
> ## (Timesys 20130708) 4.7.3
> ## (Timesys 20130708) 2.23.2
> # 227092 Dec  1 15:25 u-boot.imx
> # 173844 Dec  1 15:29 u-boot.imx
> #export PATH=$PATH:$HOME/x-tools/armv7l-timesys-linux-gnueabi/bin
> #NAME=armv7l-timesys-linux-gnueabi-
> 
> ## (crosstool-NG linaro-1.13.1-4.8-2013.10 - Linaro GCC 2013.10) 4.8.2 20131014
> ## (crosstool-NG linaro-1.13.1-4.8-2013.10 - Linaro GCC 2013.10)
> 2.23.2.20130610 Linaro 2013.10-4
> # 222996 Dec  1 15:26 u-boot.imx
> # 173844 Dec  1 15:28 u-boot.imx
> #export
> PATH=$PATH:$HOME/x-tools/gcc-linaro-arm-linux-gnueabihf-4.8-2013.10_linux/bin
> #NAME=arm-linux-gnueabihf-
> 
> make CROSS_COMPILE=$NAME vf610twr_config
> make CROSS_COMPILE=$NAME $* u-boot.imx
> cp u-boot.imx /srv/tftp
> 
> [end script]
> 
> I applied Stefan's memcpy/thumb patch, reverted c6150aaf and applied
> 'fs/ext4/ext4fs.c, fs/fs.c fs/fat/fat_write.c: Adjust 64bit math
> methods' by Tom Rini <trini at ti.com> (it has a little whitespace fat in
> it).  All of the images booted on a Vybrid Tower (Rev H) from an SD
> card.  Only issue is that I think the 'AFLAGS_NOWARN' can be removed as
> per below...
> 
> On 21 Nov 2014, stefan at agner.ch wrote:
> 
>> Resynchronize memcpy/memset with kernel and build them explicitly
>> in Thumb2 mode (unified syntax). Those assembler files can be
>> built and linked in ARM mode too, however when calling them from
>> Thumb2 built code, the stack got corrupted and the copy did not
>> succeed (the exact details have not been traced back). Hoever,
>> the Linux kernel builds those files in Thumb2 mode. Hence U-Boot
>> should build them in Thumb2 mode too when CONFIG_SYS_THUMB_BUILD
>> is set.
> 
>> To build the files without warning, some assembler instructions
>> had to be replaced with their UAL compliant variant (thanks
>> Jeroen for this input).
> 
>> To build the file in Thumb2 mode the implicit-it=always option need
>> to be set to generate Thumb2 compliant IT instructions where needed.
>> We add this option to the general AFLAGS when building for Thumb2.
> 
>> Signed-off-by: Stefan Agner <stefan at agner.ch>
>> ---
>> Changes since v1: - Don't set auto-it in AFLAGS - Removed
>> "no-warn-deprecated" warning suppression - Converted non-UAL assembler
>> instructions to their UAL compliant variants
> 
>> Tested in ARM and Thumb2 mode on Vybrid SoC. Disassembled the memset/
>> memcpy object files before and after converting the instructions to
>> UAL, the output was identical.
>>
>> arch/arm/config.mk | 4 +- arch/arm/include/asm/assembler.h | 33
>> ++++++++++-- arch/arm/lib/memcpy.S | 80 +++++++++++++++++++---------
>> arch/arm/lib/memset.S | 112 ++++++++++++++++++++------------------- 4
>> files changed, 142 insertions(+), 87 deletions(-)
>>
>> diff --git a/arch/arm/config.mk b/arch/arm/config.mk
>> index f0eafd6..14f4e9f 100644
>> --- a/arch/arm/config.mk
>> +++ b/arch/arm/config.mk
>> @@ -26,7 +26,9 @@ PLATFORM_CPPFLAGS += -D__ARM__
>>
>> # Choose between ARM/Thumb instruction sets ifeq
>> ($(CONFIG_SYS_THUMB_BUILD),y) -PF_CPPFLAGS_ARM := $(call cc-option,
>> -mthumb -mthumb-interwork,\ +AFLAGS_IMPLICIT_IT := $(call
>> as-option,-Wa$(comma)-mimplicit-it=always) +PF_CPPFLAGS_ARM :=
>> $(AFLAGS_IMPLICIT_IT) $(AFLAGS_NOWARN) \ + $(call cc-option, -mthumb
> 
> I don't think we need the '$(AFLAGS_NOWARN)' as you fixed that?  I
> removed it during my tests and didn't see anything.  Especially all
> builds produced output.  I guess this is copy/paste from a Linux
> Makefile as I don't even see where it is set in U-Boot.
> 

You are right, I removed the assignation of that but did not remove it's
inclucion into the PF_CPPFLAGS_ARM variable...

Can this be fixed by the merger or should I create a new revision?

--
Stefan

>> -mthumb-interwork,\ $(call cc-option,-marm,)\ $(call
>> cc-option,-mno-thumb-interwork,)\ ) diff --git
>> a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
>> index 5e4789b..11b80fb 100644 --- a/arch/arm/include/asm/assembler.h
>> +++ b/arch/arm/include/asm/assembler.h @@ -14,12 +14,14 @@ * assembler
>> source.  */
> 
> [snip]
> 
> Tested-by: Bill Pringlemeir <bpringlemeir at nbsps.com>