2.5.56: undefined reference to `_ebss' from drivers/mtd/maps/uclinux.c

2.5.56: undefined reference to `_ebss' from drivers/mtd/maps/uclinux.c

[Adrian Bunk]

Hi Greg,

trying to compile 2.5.56 with CONFIG_MTD_UCLINUX fails on i386 with
  undefined reference to `_ebss'
at the final linking.

It seems _ebss is only defined on the architectures m68knommu and v850?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: 2.5.56: undefined reference to `_ebss' from drivers/mtd/maps/uclinux.c

[Greg Ungerer]

Hi Adrian,

Adrian Bunk wrote:
> trying to compile 2.5.56 with CONFIG_MTD_UCLINUX fails on i386 with
>   undefined reference to `_ebss'
> at the final linking.
> 
> It seems _ebss is only defined on the architectures m68knommu and v850?

Hmm, currently that is correct. There doesn't appear to be a
"standard" symbol name applied to the immediate end of the bss
section. Different architectures are using different names:

   _ebss        -- m68knommu, v850
   __bss_stop   -- i386, alpha, ppc, s390
   __bss_end    -- x86_64
   _end         -- mips, parisc, sparc, (actually most have this)

Actually it looks like _end is probably closer, it seems to
almost always fall strait after the bss, on just about every
architecture that has it.

Come to think of it _end is probably more appropriate anyway.
Since that code is trying to find the location of something
concatenated to the end of the kernel image.

Regards
Greg


------------------------------------------------------------------------
Greg Ungerer  --  Chief Software Wizard        EMAIL:  gerg@snapgear.com
SnapGear Pty Ltd                               PHONE:    +61 7 3435 2888
825 Stanley St,                                  FAX:    +61 7 3891 3630
Woolloongabba, QLD, 4102, Australia              WEB:   www.SnapGear.com

Re: 2.5.56: undefined reference to `_ebss' from drivers/mtd/maps/uclinux.c

[Adrian Bunk]

On Mon, Jan 13, 2003 at 05:23:21PM +1000, Greg Ungerer wrote:
> Hi Adrian,
> 
> Adrian Bunk wrote:
> >trying to compile 2.5.56 with CONFIG_MTD_UCLINUX fails on i386 with
> >  undefined reference to `_ebss'
> >at the final linking.
> >
> >It seems _ebss is only defined on the architectures m68knommu and v850?
> 
> Hmm, currently that is correct. There doesn't appear to be a
> "standard" symbol name applied to the immediate end of the bss
> section. Different architectures are using different names:
> 
>   _ebss        -- m68knommu, v850
>   __bss_stop   -- i386, alpha, ppc, s390
>   __bss_end    -- x86_64
>   _end         -- mips, parisc, sparc, (actually most have this)
> 
> Actually it looks like _end is probably closer, it seems to
> almost always fall strait after the bss, on just about every
> architecture that has it.
> 
> Come to think of it _end is probably more appropriate anyway.
> Since that code is trying to find the location of something
> concatenated to the end of the kernel image.


This problem (undefined reference to `_ebss') is still present in 
2.5.65.

It might not be a solution for the whole issue, but is it intentionally
that it's possible to enable CONFIG_MTD_UCLINUX on non-uClinux 
architectures or should an appropriate dependency be added to the 
Kconfig file?


> Regards
> Greg

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

[patch] Re: 2.5.56: undefined reference to `_ebss' from drivers/mtd/maps/uclinux.c

[Adrian Bunk]

On Thu, Mar 20, 2003 at 03:59:28PM +0100, Adrian Bunk wrote:
>...
> It might not be a solution for the whole issue, but is it intentionally
> that it's possible to enable CONFIG_MTD_UCLINUX on non-uClinux 
> architectures or should an appropriate dependency be added to the 
> Kconfig file?

The following patch should do what I was thinking of:

--- linux-2.5.65-full/drivers/mtd/maps/Kconfig.old	2003-03-20 16:56:25.000000000 +0100
+++ linux-2.5.65-full/drivers/mtd/maps/Kconfig	2003-03-20 16:56:45.000000000 +0100
@@ -348,7 +348,7 @@
 
 config MTD_UCLINUX
 	tristate "Generic uClinux RAM/ROM filesystem support"
-	depends on MTD_PARTITIONS
+	depends on MTD_PARTITIONS && !MMU
 	help
 	  Map driver to support image based filesystems for uClinux.
 


Any comments on whether this is correct?


cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [patch] Re: 2.5.56: undefined reference to `_ebss' from drivers/mtd/maps/uclinux.c

[Greg Ungerer]

Hi Adrian,

This seems reasonable to me. It is after all targeted at uclinux.
I suspect noone with VM setups would be much interrested in using
it anyway.

Patch looks good to me.

Regards
Greg



Adrian Bunk wrote:
> On Thu, Mar 20, 2003 at 03:59:28PM +0100, Adrian Bunk wrote:
> 
>>...
>>It might not be a solution for the whole issue, but is it intentionally
>>that it's possible to enable CONFIG_MTD_UCLINUX on non-uClinux 
>>architectures or should an appropriate dependency be added to the 
>>Kconfig file?
> 
> 
> The following patch should do what I was thinking of:
> 
> --- linux-2.5.65-full/drivers/mtd/maps/Kconfig.old	2003-03-20 16:56:25.000000000 +0100
> +++ linux-2.5.65-full/drivers/mtd/maps/Kconfig	2003-03-20 16:56:45.000000000 +0100
> @@ -348,7 +348,7 @@
>  
>  config MTD_UCLINUX
>  	tristate "Generic uClinux RAM/ROM filesystem support"
> -	depends on MTD_PARTITIONS
> +	depends on MTD_PARTITIONS && !MMU
>  	help
>  	  Map driver to support image based filesystems for uClinux.
>  
> 
> 
> Any comments on whether this is correct?
> 
> 
> cu
> Adrian
> 

-- 
------------------------------------------------------------------------
Greg Ungerer  --  Chief Software Wizard        EMAIL:  gerg@snapgear.com
SnapGear Pty Ltd                               PHONE:    +61 7 3435 2888
825 Stanley St,                                  FAX:    +61 7 3891 3630
Woolloongabba, QLD, 4102, Australia              WEB:   www.SnapGear.com