[PATCH v2 5/5] ARM: omap3: Thumb-2 compatibility for sleep34xx.S

[Dave Martin]

On Thu, Feb 10, 2011 at 10:17 PM, Kevin Hilman <khilman at ti.com> wrote:
> Dave Martin <dave.martin at linaro.org> writes:
>
>>  * Use BSYM() to get the correct Thumb branch address
>>    for adr <Rd>, <label>
>>
>>  * Fix an out-of-range ADR when building for ARM
>>
>>  * Correctly call es3_sdrc_fix as Thumb when copied to SRAM.
>>
>>  * Remove deprecated/undefined PC-relative stores
>>
>>  * Add the required ENDPROC() directive for each ENTRY().
>>
>>  * .align before data words
>>
>> Signed-off-by: Dave Martin <dave.martin at linaro.org>
>
> I'm attempting to test this series with OMAP PM, but some changes here
> don't compile for me.
>
> My toolchain is: gcc version 4.5.1 (Sourcery G++ Lite 2010.09-50)
>
> First, I merged your arm/omap-thumb2+merged branch with my pm branch
> from git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-omap-pm.git
>
> There were some minor conflicts here, but they looked simple enough and
> I just resolved in favor of your branch.

Thanks for giving it a try.

>
> Trying to build with CONFIG_THUMB2_KERNEL=y, I ran into a compile
> problem...
>
>

[...]

>> +     adr     r0, es3_sdrc_fix        @ Not using BSYM clears the Thumb bit.
>
> This fails to compile:
>
> /work/kernel/omap/pm/arch/arm/mach-omap2/sleep34xx.S: Assembler messages:
> /work/kernel/omap/pm/arch/arm/mach-omap2/sleep34xx.S:361: Error: invalid immediate for address calculation (value = 0x00000004)

Unfortunately, this is caused by a bug in the assembler.
arch/arm/kernel/relocate_kernel.S also suffers from the same bug when
built with CONFIG_THUMB2_KERNEL.

If you had got as far a linking, it's likely you would hit a
'reference to discarded section problem' error in the linker, due to
discarding of some sections referenced by SMP_ON_UP fixups.

If you merge the 3 extra patches from dirty/arm/omap-thumb2+merged it
should resolve these issues, but how to fix these things upstream is
still under discussion.

Cheers
---Dave