In message 1250507849-31660-1-git-send-email-wd@denx.de I wrote:
For some time there have been repeated reports about build problems with some ARM (cross) tool chains. Especially issues about (in)compatibility with the tool chain provided runtime support library libgcc.a caused to add and support a private implementation of such runtime support code in U-Boot. A closer look at the code indicated that some of these issues are actually home-made. This patch attempts to clean up some of the most obvious problems and make building of U-Boot with different tool chains easier:
Even though all ARM systems basicy used the same compiler options to select a specific ABI from the tool chain, the code for this was distributed over all cpu/*/config.mk files. We move this one level up into lib_arm/config.mk instead.
So far, we only checked if "-mapcs-32" was supported by the tool chain; if yes, this was used, if not, "-mabi=apcs-gnu" was selected, no matter if the tool chain actually understood this option. There was no support for EABI conformant tool chains. This patch implements the following logic:
- If the tool chain supports
"-mabi=aapcs-linux -mno-thumb-interwork" we use these options (EABI conformant tool chain). 2) Otherwise, we check first if "-mapcs-32" is supported, and then check for "-mabi=apcs-gnu" If one test succeeds, we use the first found option. 3) In case 2), we also test if "-mno-thumb-interwork", and use this if the test succeeds. [For "-mabi=aapcs-linux" we set "-mno-thumb-interwork" mandatorily.]
This way we use a similar logic for the compile options as the Linux kenrel does.
Some EABI conformant tool chains cause external references to utility functions like raise(); such functions are provided in the new file lib_arm/eabi_compat.c
Note that lib_arm/config.mk gets parsed several times, so we must make sure to add eabi_compat.o only once to the linker list.
Signed-off-by: Wolfgang Denk wd@denx.de Cc: Jean-Christophe PLAGNIOL-VILLARD plagnioj@jcrosoft.com Cc: Dirk Behme dirk.behme@googlemail.com Cc: Magnus Lilja lilja.magnus@gmail.com Cc: Tom Rix Tom.Rix@windriver.com Cc: Prafulla Wadaskar prafulla@marvell.com
I have run a full "MAKEALL arm" for ELDK releases 3.1 (gcc 3.3.3), 3.1.1 (gcc 3.3.3), 4.1 (gcc 4.0.0) and 4.2 (gcc 4.2.2, both as "arm" [softfloat] and "armVFP" [VFP hardfloat]), and all of these both with USE_PRIVATE_LIBGCC=yes (i. e. using U-Boot internal libgcc replacement code) and without (i. e. using the tool chain provided standard libgcc instead).
The ELDK fails to build the big-endian IXP boards, but this is a restriction of the ELDK, not a new issue introcued by this patch. Except of this, all build were succesful.
Note 1: Please note that older tool chains (based on binutils versions older than 2.16) will have problems with the SORT_BY_ALIGNMENT() and SORT_BY_NAME() functions introduced to the linker scripts with commit f62fb99941c6. I'll soon submit a patch to fix this issue. Final tests are running right now.
Note 2: Even though this is a bigger change, I consider it a bug fix and therefor tend to have it included into the upcoming release. Of course this requires sufficient test coverage and feedback. Please help!!
Note 3: Most ARM systems also define this: PLATFORM_RELFLAGS +=$(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) I guess this can be unified and moved to lib_arm/config.mk, too, but I would like to handle this in a separate, later patch. This makes testing (and bisecting) easier, and it is a non-critical problem.
config.mk | 2 +- cpu/arm1136/config.mk | 2 -- cpu/arm1176/config.mk | 2 -- cpu/arm1176/s3c64xx/config.mk | 1 - cpu/arm720t/config.mk | 2 -- cpu/arm920t/config.mk | 2 -- cpu/arm925t/config.mk | 2 -- cpu/arm926ejs/config.mk | 2 -- cpu/arm926ejs/davinci/config.mk | 2 -- cpu/arm946es/config.mk | 2 -- cpu/arm_cortexa8/config.mk | 1 - cpu/arm_cortexa8/omap3/board.c | 7 ------- cpu/arm_intcm/config.mk | 2 -- cpu/ixp/config.mk | 1 - cpu/lh7a40x/config.mk | 2 -- cpu/pxa/config.mk | 2 -- cpu/s3c44b0/config.mk | 2 -- cpu/sa1100/config.mk | 2 -- lib_arm/Makefile | 15 ++++++++++++--- lib_arm/config.mk | 28 ++++++++++++++++++++++++++++ lib_arm/eabi_compat.c | 18 ++++++++++++++++++ 21 files changed, 59 insertions(+), 40 deletions(-) create mode 100644 lib_arm/eabi_compat.c
Applied.
Thanks to everybody who helped testing.
Best regards,
Wolfgang Denk