[U-Boot] [PATCH] ARMv7: Fix linker errors across toolchain versions

[Albert ARIBAUD <albert.aribaud@free.fr>]

Hi Wolfgang,

Le 02/12/2010 08:34, Wolfgang Denk a ?crit :
> Dear Albert ARIBAUD,
>
> In message<4CF743E6.60706@free.fr>  you wrote:
>>
>> Starting with the fact that the linker issue is only for one board,
>> omap3_evm, I looked up the board-specific code. First thing that I
>> noticed was
>>
>> 	static u8 omap3_evm_version;
>>
>> I changed this to
>>
>> 	static u8 omap3_evm_version = 1;
>>
>> so that the static was moved out of BSS and the linker warning
>> disappeared (reminder: v2010.12-rc2, omap3_evm, arm-2010q1).
>>
>> Now this is not the first static BSS variable we use in U-Boot, and the
>> others did not cause linker warnings (not *all* the others, at least),
>> so the real cause is yet unknown to me. But that's at least a lead we
>> can follow.
>
> Write access is only in omap3_evm_get_revision() which in turn only
> gets called in misc_init_r(), i. e. after relocation.
>
> Read access is only in get_omap3_evm_rev() [which is not called
> outside this file and thus should be made static!] which gets called
> only in omap3_evm_need_extvbus() which gets acalled only in
> musb_platform_init(), i. e. during USB init.
>
> This should be safe.

Alright.

> You could try out what happens if you make get_omap3_evm_rev() static...

No change: the warning remains, and so do the two segments.

Maybe I should subscribe the binutils list and ask there.

Meanwhile, this variable could be initialized to some safe value such as 
OMAP3EVM_BOARD_UNKNOWN.

BTW... Why on Earth is it an uint8? Probably a space saving measure, but 
one I think is not really fruitful, because of probable paddings and 
alignments; making it an int would allow using smsc_id directly as 
values for the OMAP3EVM_BOARD_GEN_1 and OMAP3EVM_BOARD_GEN_2...

... plus it removes the linker warning!

I thus suggest turning omap3_evm_version from uint8 to int and get on 
with debugging the board.

> Best regards,
>
> Wolfgang Denk

Amicalement,
-- 
Albert.