Hi Stefan,
On 21 November 2014 at 08:34, Stefan Agner stefan@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@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
Reviewed-by: Simon Glass sjg@chromium.org
Tested on pit and found that it fixed the problem with Thumb mode. Still works fine in ARM mode.
Tested-by: Simon Glass sjg@chromium.org
A few nits: - typo 'Hoever' in commit message - you could mention the Linux commit/release you synced to
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(-)
Regards, Simon