Turn __bss_start and __bss_end__ from linker-generated to compiler-generated symbols, causing relocations for these symbols to change type, from R_ARM_ABS32 to R_ARM_RELATIVE.
This should have no functional impact, as it affects references to __bss_start and __bss_end__ only before relocation, and no such references are done.
Signed-off-by: Albert ARIBAUD albert.u.boot@aribaud.net --- Changes in v2: - made BSS start and end compiler-generated
arch/arm/cpu/ixp/u-boot.lds | 12 ++++++++--- arch/arm/cpu/u-boot.lds | 12 ++++++++--- arch/arm/lib/Makefile | 1 + arch/arm/lib/bss.c | 39 ++++++++++++++++++++++++++++++++++++ board/actux1/u-boot.lds | 22 +++++++++++++------- board/actux2/u-boot.lds | 22 +++++++++++++------- board/actux3/u-boot.lds | 16 +++++++++++---- board/dvlhost/u-boot.lds | 16 +++++++++++---- board/freescale/mx31ads/u-boot.lds | 14 +++++++++---- 9 files changed, 122 insertions(+), 32 deletions(-) create mode 100644 arch/arm/lib/bss.c
diff --git a/arch/arm/cpu/ixp/u-boot.lds b/arch/arm/cpu/ixp/u-boot.lds index 81d954f..bba91d5 100644 --- a/arch/arm/cpu/ixp/u-boot.lds +++ b/arch/arm/cpu/ixp/u-boot.lds @@ -67,11 +67,17 @@ SECTIONS
_end = .;
- .bss __rel_dyn_start (OVERLAY) : { - __bss_start = .; + .bss_start __rel_dyn_start (OVERLAY) : { + KEEP(*(.__bss_start)); + } + + .bss __bss_start (OVERLAY) : { *(.bss*) . = ALIGN(4); - __bss_end__ = .; + ___bssend___ = .; + } + .bss_end ___bssend___ (OVERLAY) : { + KEEP(*(.__bss_end__)); }
/DISCARD/ : { *(.dynstr*) } diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds index e6b202b..e1bc8e7 100644 --- a/arch/arm/cpu/u-boot.lds +++ b/arch/arm/cpu/u-boot.lds @@ -81,11 +81,17 @@ SECTIONS *(.mmutable) }
- .bss __rel_dyn_start (OVERLAY) : { - __bss_start = .; + .bss_start __rel_dyn_start (OVERLAY) : { + KEEP(*(.__bss_start)); + } + + .bss __bss_start (OVERLAY) : { *(.bss*) . = ALIGN(4); - __bss_end__ = .; + ___bssend___ = .; + } + .bss_end ___bssend___ (OVERLAY) : { + KEEP(*(.__bss_end__)); }
/DISCARD/ : { *(.dynstr*) } diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile index 57111af..11c2674 100644 --- a/arch/arm/lib/Makefile +++ b/arch/arm/lib/Makefile @@ -39,6 +39,7 @@ GLCOBJS += div0.o SOBJS-y += crt0.o
ifndef CONFIG_SPL_BUILD +COBJS-y += bss.o COBJS-y += board.o COBJS-y += bootm.o COBJS-$(CONFIG_SYS_L2_PL310) += cache-pl310.o diff --git a/arch/arm/lib/bss.c b/arch/arm/lib/bss.c new file mode 100644 index 0000000..7c0b154 --- /dev/null +++ b/arch/arm/lib/bss.c @@ -0,0 +1,39 @@ +/* + * Copyright 2013 Albert ARIBAUD albert.u.boot@aribaud.net + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +/** + * These two symbols are declared in a C file so that the linker + * uses R_ARM_RELATIVE relocation, rather than the R_ARM_ABS32 one + * it would use if the symbols were defined in the linker file. + * Using only R_ARM_RELATIVE relocation ensures that references to + * the symbols are correct after as well as before relocation. + * + * We need a 0-byte-size type for these symbols, and the compiler + * does not allow defining objects of C type 'void'. Using an empty + * struct is allowed by the compiler, but causes gcc versions 4.4 and + * below to complain about aliasing. Therefore we use the next best + * thing: zero-sized arrays, which are both 0-byte-size and exempt from + * aliasing warnings. + */ + +char __bss_start[0] __attribute__((used, section(".__bss_start"))); +char __bss_end__[0] __attribute__((used, section(".__bss_end__"))); diff --git a/board/actux1/u-boot.lds b/board/actux1/u-boot.lds index c41eed0..572bcea 100644 --- a/board/actux1/u-boot.lds +++ b/board/actux1/u-boot.lds @@ -41,15 +41,15 @@ SECTIONS *(.text*) }
- . = ALIGN (4); + . = ALIGN(4); .rodata : { *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*))) } - . = ALIGN (4); + . = ALIGN(4); .data : { *(.data*) } - . = ALIGN (4); + . = ALIGN(4); .got : { *(.got) } @@ -72,13 +72,21 @@ SECTIONS *(.dynsym) }
- .bss __rel_dyn_start (OVERLAY) : { - __bss_start = .; + _end = .; + + .bss_start __rel_dyn_start (OVERLAY) : { + KEEP(*(.__bss_start)); + } + + .bss __bss_start (OVERLAY) : { *(.bss*) . = ALIGN(4); - _end = .; + ___bssend___ = .; } - __bss_end__ =.; + .bss_end ___bssend___ (OVERLAY) : { + KEEP(*(.__bss_end__)); + } + /DISCARD/ : { *(.dynstr*) } /DISCARD/ : { *(.dynamic*) } /DISCARD/ : { *(.plt*) } diff --git a/board/actux2/u-boot.lds b/board/actux2/u-boot.lds index 8409984..6272a10 100644 --- a/board/actux2/u-boot.lds +++ b/board/actux2/u-boot.lds @@ -41,15 +41,15 @@ SECTIONS *(.text*) }
- . = ALIGN (4); + . = ALIGN(4); .rodata : { *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*))) } - . = ALIGN (4); + . = ALIGN(4); .data : { *(.data*) } - . = ALIGN (4); + . = ALIGN(4); .got : { *(.got) } @@ -72,13 +72,21 @@ SECTIONS *(.dynsym) }
- .bss __rel_dyn_start (OVERLAY) : { - __bss_start = .; + _end = .; + + .bss_start __rel_dyn_start (OVERLAY) : { + KEEP(*(.__bss_start)); + } + + .bss __bss_start (OVERLAY) : { *(.bss*) . = ALIGN(4); - _end = .; + ___bssend___ = .; } - __bss_end__ =.; + .bss_end ___bssend___ (OVERLAY) : { + KEEP(*(.__bss_end__)); + } + /DISCARD/ : { *(.dynstr*) } /DISCARD/ : { *(.dynamic*) } /DISCARD/ : { *(.plt*) } diff --git a/board/actux3/u-boot.lds b/board/actux3/u-boot.lds index a3bd02b..488e1e7 100644 --- a/board/actux3/u-boot.lds +++ b/board/actux3/u-boot.lds @@ -72,13 +72,21 @@ SECTIONS *(.dynsym) }
- .bss __rel_dyn_start (OVERLAY) : { - __bss_start = .; + _end = .; + + .bss_start __rel_dyn_start (OVERLAY) : { + KEEP(*(.__bss_start)); + } + + .bss __bss_start (OVERLAY) : { *(.bss*) . = ALIGN(4); - _end = .; + ___bssend___ = .; } - __bss_end__ =.; + .bss_end ___bssend___ (OVERLAY) : { + KEEP(*(.__bss_end__)); + } + /DISCARD/ : { *(.dynstr*) } /DISCARD/ : { *(.dynamic*) } /DISCARD/ : { *(.plt*) } diff --git a/board/dvlhost/u-boot.lds b/board/dvlhost/u-boot.lds index 1bd1700..6dc26c8 100644 --- a/board/dvlhost/u-boot.lds +++ b/board/dvlhost/u-boot.lds @@ -72,13 +72,21 @@ SECTIONS *(.dynsym) }
- .bss __rel_dyn_start (OVERLAY) : { - __bss_start = .; + _end = .; + + .bss_start __rel_dyn_start (OVERLAY) : { + KEEP(*(.__bss_start)); + } + + .bss __bss_start (OVERLAY) : { *(.bss*) . = ALIGN(4); - _end = .; + ___bssend___ = .; } - __bss_end__ =.; + .bss_end ___bssend___ (OVERLAY) : { + KEEP(*(.__bss_end__)); + } + /DISCARD/ : { *(.dynstr*) } /DISCARD/ : { *(.dynamic*) } /DISCARD/ : { *(.plt*) } diff --git a/board/freescale/mx31ads/u-boot.lds b/board/freescale/mx31ads/u-boot.lds index 5267729..12d7c12 100644 --- a/board/freescale/mx31ads/u-boot.lds +++ b/board/freescale/mx31ads/u-boot.lds @@ -80,11 +80,17 @@ SECTIONS
_end = .;
- .bss __rel_dyn_start (OVERLAY) : { - __bss_start = .; - *(.bss) + .bss_start __rel_dyn_start (OVERLAY) : { + KEEP(*(.__bss_start)); + } + + .bss __bss_start (OVERLAY) : { + *(.bss*) . = ALIGN(4); - __bss_end__ = .; + ___bssend___ = .; + } + .bss_end ___bssend___ (OVERLAY) : { + KEEP(*(.__bss_end__)); }
/DISCARD/ : { *(.bss*) }