mpc85xx/u-boot*.lds: remove _GLOBAL_OFFSET_TABLE_ definition

PATCH New Prabhakar Kushwaha 5 participants 5 messages Oct 25, 2015 – Nov 10, 2015 PowerPC

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Prabhakar Kushwaha

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2015-10-25 05:02 UTC #0 lore raw

PATCH v2 1/1 mpc85xx/u-boot*.lds: remove _GLOBAL_OFFSET_TABLE_ definition

From: Zhenhua Luo <[email protected]>

In binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbols defined by PROVIDE in u-boot.lds overrides the linker built-in symbols
(https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;
h=b893397a4b1316610f49819344817715e4305de9),
so the linker is treating _GLOBAL_OFFSET_TABLE_ as a definition into the .reloc section.

To align with the change of binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbol should not be defined in sections, and the symbols in linker generated .got section should be used(https://sourceware.org/ml/binutils/2008-09/ msg00122.html)

Fixed the following build errors with binutils-2.25:
| powerpc-poky-linux-gnuspe-ld.bfd: _GLOBAL_OFFSET_TABLE_ not defined in linker created .got

Signed-off-by Zhenhua Luo <[email protected]>

Signed-off-by Prabhakar Kushwaha <[email protected]>

---
Changes for v2: Updated Subject

 arch/powerpc/cpu/mpc85xx/u-boot-nand.lds     | 1 -
 arch/powerpc/cpu/mpc85xx/u-boot-nand_spl.lds | 1 -
 arch/powerpc/cpu/mpc85xx/u-boot-spl.lds      | 1 -
 arch/powerpc/cpu/mpc85xx/u-boot.lds          | 1 -
 4 files changed, 4 deletions(-)

arch/powerpc/cpu/mpc85xx/u-boot-nand.lds +0 -1

index f933b21..0399f93 100644
@@ -44,7 +44,6 @@ SECTIONS
     _GOT2_TABLE_ = .;
     KEEP(*(.got2))
     KEEP(*(.got))
-    PROVIDE(_GLOBAL_OFFSET_TABLE_ = . + 4);
     _FIXUP_TABLE_ = .;
     KEEP(*(.fixup))
   }

arch/powerpc/cpu/mpc85xx/u-boot-nand_spl.lds +0 -1

index b83c553..f044564 100644
@@ -22,7 +22,6 @@ SECTIONS
 		_GOT2_TABLE_ = .;
 		KEEP(*(.got2))
 		KEEP(*(.got))
-		PROVIDE(_GLOBAL_OFFSET_TABLE_ = . + 4);
 		_FIXUP_TABLE_ = .;
 		KEEP(*(.fixup))
 	}

arch/powerpc/cpu/mpc85xx/u-boot-spl.lds +0 -1

index 5ae7b3e..889a4c2 100644
@@ -29,7 +29,6 @@ SECTIONS
 		_GOT2_TABLE_ = .;
 		KEEP(*(.got2))
 		KEEP(*(.got))
-		PROVIDE(_GLOBAL_OFFSET_TABLE_ = . + 4);
 		_FIXUP_TABLE_ = .;
 		KEEP(*(.fixup))
 	}

arch/powerpc/cpu/mpc85xx/u-boot.lds +0 -1

index 2cf0b25..f15eaf3 100644
@@ -50,7 +50,6 @@ SECTIONS
     _GOT2_TABLE_ = .;
     KEEP(*(.got2))
     KEEP(*(.got))
-    PROVIDE(_GLOBAL_OFFSET_TABLE_ = . + 4);
     _FIXUP_TABLE_ = .;
     KEEP(*(.fixup))
   }

Signature · 1 line

1.9.1

York Sun

2015-10-30 17:12 UTC #1 lore raw

PATCH v2 1/1 mpc85xx/u-boot*.lds: remove _GLOBAL_OFFSET_TABLE_ definition

Quoted 14 lines · Prabhakar Kushwaha

From: Zhenhua Luo <[email protected]>
In binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbols defined by PROVIDE in u-boot.lds overrides the linker built-in symbols
(https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;
h=b893397a4b1316610f49819344817715e4305de9),
so the linker is treating _GLOBAL_OFFSET_TABLE_ as a definition into the .reloc section.
To align with the change of binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbol should not be defined in sections, and the symbols in linker generated .got section should be used(https://sourceware.org/ml/binutils/2008-09/ msg00122.html)

Quoted 9 lines

Fixed the following build errors with binutils-2.25:
| powerpc-poky-linux-gnuspe-ld.bfd: _GLOBAL_OFFSET_TABLE_ not defined in linker created .got
Signed-off-by Zhenhua Luo <[email protected]>
Signed-off-by Prabhakar Kushwaha <[email protected]>
---
Changes for v2: Updated Subject

Prabhakar/Zhenghua,

Have you addressed Tom's comment (on rev 1 patch)? Quote, "What happens when we use older binutils? I'd like some run-time testing too please".

York

Joakim Tjernlund

2015-11-02 16:17 UTC #2 lore raw

PATCH v2 1/1 mpc85xx/u-boot*.lds: remove _GLOBAL_OFFSET_TABLE_ definition

Quoted 8 lines · York Sun

Quoted 6 lines · Prabhakar Kushwaha
From: Zhenhua Luo <[email protected]>
In binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbols defined by PROVIDE in u-boot.lds overrides the linker built-in symbols
(https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;
h=b893397a4b1316610f49819344817715e4305de9),

hmm, what was the reson for this change in binutils? As I recall, PROVIDE should only add a symbol when there is none and now binutils just ignores this, strange.

Quoted 2 lines

Quoted 2 lines
so the linker is treating _GLOBAL_OFFSET_TABLE_ as a definition into the .reloc section.

Yes, where do you want it instead? what is the difference with/without PROVIDE?

Quoted 26 lines

Quoted 6 lines
To align with the change of binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbol should not be defined in sections, and the symbols in linker generated .got section should be used(https://sourceware.org/ml/binutils/2008-09/ msg00122.html)
Fixed the following build errors with binutils-2.25:
Quoted 8 lines
Quoted 1 line
powerpc-poky-linux-gnuspe-ld.bfd: _GLOBAL_OFFSET_TABLE_ not defined in
linker created .got
Signed-off-by Zhenhua Luo <[email protected]>
Signed-off-by Prabhakar Kushwaha <[email protected]>
---
Changes for v2: Updated Subject
Prabhakar/Zhenghua,
Have you addressed Tom's comment (on rev 1 patch)? Quote, "What happens when we use older binutils? I'd like some run-time testing too please".
York
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Joakim Tjernlund

2015-11-02 18:48 UTC #3 lore raw

PATCH v2 1/1 mpc85xx/u-boot*.lds: remove _GLOBAL_OFFSET_TABLE_ definition

[Resending with old email address]

I want to add why PROVIDE was added in the first place:
In theory it is possible to build an u-boot without ld defining _GLOBAL_OFFSET_TABLE_, in that case we create _GLOBAL_OFFSET_TABLE_ ourself.

Should we start using -fPIC* one day this will we will be close to an u-boot without _GLOBAL_OFFSET_TABLE_ and the __got2_entries calculation will fail.

*older gcc's will automatically promote -fpic to -fPIC when used with -mrelocatable
I wrote a small patch in 2010 to fix this:
https://gcc.gnu.org/ml/gcc-patches/2010-10/msg02301.html
Cannot remember what gcc version(4.6?) that went into.

About the same time support for -msingle-pic-base was added to powerpc gcc This would reduce code size further, possibly interesting for SPL? I sent som patches for that but there were something holding them back.

Quoted 44 lines · Joakim Tjernlund

Quoted 8 lines · York Sun
Quoted 6 lines · Prabhakar Kushwaha
From: Zhenhua Luo <[email protected]>
In binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbols defined by PROVIDE in u-boot.lds overrides the linker built-in symbols
(https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;
h=b893397a4b1316610f49819344817715e4305de9),
hmm, what was the reson for this change in binutils? As I recall, PROVIDE should only add a symbol when there is none and now binutils just ignores this, strange.
Quoted 2 lines
Quoted 2 lines
so the linker is treating _GLOBAL_OFFSET_TABLE_ as a definition into the .reloc section.
Yes, where do you want it instead? what is the difference with/without PROVIDE?
Quoted 26 lines
Quoted 6 lines
To align with the change of binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbol should not be defined in sections, and the symbols in linker generated .got section should be used(https://sourceware.org/ml/binutils/2008-09/ msg00122.html)
Fixed the following build errors with binutils-2.25:
Quoted 8 lines
Quoted 1 line
powerpc-poky-linux-gnuspe-ld.bfd: _GLOBAL_OFFSET_TABLE_ not defined in
linker created .got
Signed-off-by Zhenhua Luo <[email protected]>
Signed-off-by Prabhakar Kushwaha <[email protected]>
---
Changes for v2: Updated Subject
Prabhakar/Zhenghua,
Have you addressed Tom's comment (on rev 1 patch)? Quote, "What happens when we use older binutils? I'd like some run-time testing too please".
York
_______________________________________________
U-Boot mailing list
U-Boot at lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot

Tom Rini

2015-11-10 20:16 UTC #4 lore raw

PATCH v2 1/1 mpc85xx/u-boot*.lds: remove _GLOBAL_OFFSET_TABLE_ definition

In reply to Prabhakar Kushwaha

Quoted 14 lines · Prabhakar Kushwaha

From: Zhenhua Luo <[email protected]>
In binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbols defined by PROVIDE in u-boot.lds overrides the linker built-in symbols
(https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;
h=b893397a4b1316610f49819344817715e4305de9),
so the linker is treating _GLOBAL_OFFSET_TABLE_ as a definition into the .reloc section.
To align with the change of binutils-2.25, the _GLOBAL_OFFSET_TABLE_ symbol should not be defined in sections, and the symbols in linker generated .got section should be used(https://sourceware.org/ml/binutils/2008-09/ msg00122.html)

Quoted 6 lines

Fixed the following build errors with binutils-2.25:
| powerpc-poky-linux-gnuspe-ld.bfd: _GLOBAL_OFFSET_TABLE_ not defined in linker created .got
Signed-off-by Zhenhua Luo <[email protected]>
Signed-off-by Prabhakar Kushwaha <[email protected]>

Applied to u-boot/master, thanks!

Signature · 8 lines

Tom
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