Hi Michal,
On Thu, 25 Jul 2013 16:16:46 +0200, Michal Simek michal.simek@xilinx.com wrote:
Remove ARM eabi exception handling tables (for frame unwinding). AFAICT, u-boot stubs away the frame unwiding routines, so the tables will more or less just consume space. It should be OK to remove them.
Signed-off-by: Edgar E. Iglesias edgar.iglesias@xilinx.com Signed-off-by: Michal Simek michal.simek@xilinx.com
This patch was sent to ML as RFC (May 9)
Here is the origin response in connection to this patch.
Ok, so Michal and I just did some fiddling with zynq builds and *exidx* sections.
By default the *exidx* sections are between rodata and data, so removing them causes many apparent changes at the binary level. However, builds of zynq based on ARM master with the patch above vs master with a patch mapping *exidx* sections after BSS gives identical binaries. Thus the RFC has no functional effect.
Also, ARM EHABI states that [exception] Tables are not required for ABI compliance at the C/Assembler level but are required for C++.
http://infocenter.arm.com/help/topic/com.arm.doc.ihi0038a/IHI0038A_ehabi.pdf
So as long as we don't put any C++ code in U-Boot (a prospect that I don't see happening any time soon), this RFC is safe and either is a no-op or removes useless bytes from the binary.
arch/arm/cpu/u-boot.lds | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds index 3037885..8894c8a 100644 --- a/arch/arm/cpu/u-boot.lds +++ b/arch/arm/cpu/u-boot.lds @@ -113,4 +113,6 @@ SECTIONS /DISCARD/ : { *(.plt*) } /DISCARD/ : { *(.interp*) } /DISCARD/ : { *(.gnu*) }
- /DISCARD/ : { *(.ARM.exidx*) }
- /DISCARD/ : { *(.gnu.linkonce.armexidx.*) }
}
1.8.2.3
Applied to u-boot-arm/master, thanks!
Amicalement,