[U-Boot] Build failures with older toolchain

[Dirk Behme <dirk.behme@googlemail.com>]

On 30.11.2010 15:25, Premi, Sanjeev wrote:
>> -----Original Message-----
>> From: u-boot-bounces at lists.denx.de
>> [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Premi, Sanjeev
>> Sent: Monday, November 29, 2010 8:38 PM
>> To: Wolfgang Denk
>> Cc: u-boot at lists.denx.de
>> Subject: Re: [U-Boot] Build failures with older toolchain
>>
>
> [snip]...[snip]
>
>>>>
>>>>       I am process of downloading the 2009q3 version from
>>> codesourcery
>>>>       Albert mentioned he is using it. Are you on the same
>> version as
>>>>       well?
>>>
>>> No, I'm using ELDk 4.2
>>
>> [sp] Okay, so I downloaded both 2009-q3 and 2010.09-50 versions of the
>>       Codesourcery Lite edition.
>>
>>       There is no difference in the observations between
>> 2009q3 and 2010q1.
>>
> [sp] I have been able to narrow down the problem to one variable defined
>       in board/ti/evm.c - omap3_evm_version - declared as:
>        static u8 omap3_evm_version;
>
>       Any attempt to assign value this variable in omap3_evm_get_revision()
>       leads to the linker error I noted with Codesourcery 2010q1-202.
>
>       With 2009q1-203, definition of variable itself is sufficient to cause
>       the linker error.

Maybe CCing Codesourcery's mailing list

http://www.codesourcery.com/archives/arm-gnu-discuss/maillist.html

could help, too? At least it's worth a try?

Dirk

>       I have pasted a patch below that constructs the testcase I have created
>       to explain these observations:
>       1) When macros both _EXCLUDE_ME_1 and _EXCLUDE_ME_2 are undefined, the
>          problem is - as described.
>
>       2) When only macro _EXCLUDE_ME_1 is defined, the compilation succeeds
>          with Codesourcery 2010q1-202; but fails with 2009q1-203.
>
>       3) When both macros _EXCLUDE_ME_1 and _EXCLUDE_ME_2 are defined, the
>          compilation succeeds with both codesourcery versions.
>
>       OMAP3EVM is obviously not the only file using statics. I see their usage
>       in many files including OMAP3Beagle as well - one reason I did not even
>       suspect this to be problem.
>
>       I haven't yet been able to conclude the cause of failure - but appears
>       to be related to handling of static variables across compiler versions.
>       Still need to investigate further on this...
>
>       Board revision needs to be detected early during initialization. How is
>       this handled for other boards? (I am currently trying to browse non-omap
>       boards for pointers). Any quick suggestions would be helpful.
>
> [patch]
> diff --git a/board/ti/evm/evm.c b/board/ti/evm/evm.c
> index 09d14f7..e766355 100644
> --- a/board/ti/evm/evm.c
> +++ b/board/ti/evm/evm.c
> @@ -37,15 +37,30 @@
>   #include<asm/mach-types.h>
>   #include "evm.h"
>
> +/* #define _EXCLUDE_ME_1 */	/* Uncomment - works with 2010q1 only */
> +/* #define _EXCLUDE_ME_2 */	/* Uncomment - works with 2009q3 as well */
> +
> +#if !defined(_EXCLUDE_ME_2)
>   static u8 omap3_evm_version;
> +#endif
>
>   u8 get_omap3_evm_rev(void)
>   {
> +#ifdef _EXCLUDE_ME_2
> +	return OMAP3EVM_BOARD_GEN_1; /* Debugging: Don't use the variable */
> +#else
>   	return omap3_evm_version;
> +#endif
> +
>   }
>
>   static void omap3_evm_get_revision(void)
>   {
> +#ifdef _EXCLUDE_ME_COMPLETELY_
> +	/*
> +	 * Original code in the function is being removed completely to reduce
> +	 * scope of the debug exercise.
> +	 */
>   #if defined(CONFIG_CMD_NET)
>   	/*
>   	 * Board revision can be ascertained only by identifying
> @@ -80,6 +95,20 @@ static void omap3_evm_get_revision(void)
>   	omap3_evm_version = OMAP3EVM_BOARD_GEN_2;
>   #endif
>   #endif	/* CONFIG_CMD_NET */
> +
> +#else
> +	/*
> +	 * Dummy implementation of function just for testing
> +	 */
> +
> +#if !defined(_EXCLUDE_ME_1)&&  !defined(_EXCLUDE_ME_2)
> +	/*
> +	 * Dummy assignment just for testing
> +	 */
> +	omap3_evm_version = OMAP3EVM_BOARD_GEN_2;
> +#endif
> +
> +#endif	/* _EXCLUDE_ME_COMPLETELY_ */
>   }
>
>   #ifdef CONFIG_USB_OMAP3
> [/patch]
>
> [snip]
> Removed my observations for Codesourcery 2010.09-50.
> Did not get chance to look at them so far...
> [/snip]
>
> Best regards,
> Sanjeev
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