Wolfgang Denk 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
MAKEALL arm with CodeSourcery's arm-2008q3-72-arm-none-linux-gnueabi-i686-pc-linux-gnu arm-2009q1-203-arm-none-linux-gnueabi-i686-pc-linux-gnu
and this patch differ from
USE_PRIVATE_LIBGCC=yes ./MAKEALL arm
only in these targets
actux1 actux2 actux3 actux4 ixdp425 ixdpg425 pdnb3 scpu trab
As already mentioned already by
http://lists.denx.de/pipermail/u-boot/2009-August/058838.html
Tested-by : Tom Rix Tom.Rix@windriver.com