Patchwork [U-Boot,v1] arm: remove unneeded symbol offsets and _TEXT_BASE

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Submitter Albert ARIBAUD
Date Oct. 13, 2013, 7:10 a.m.
Message ID <1381648228-24373-1-git-send-email-albert.u.boot@aribaud.net>
Download mbox | patch
Permalink /patch/283058/
State Superseded
Delegated to: Albert ARIBAUD
Headers show

Comments

Albert ARIBAUD - Oct. 13, 2013, 7:10 a.m.
Remove the last uses of symbol offsets in ARM U-Boot.
Remove some needless uses of _TEXT_BASE.
Remove all _TEXT_BASE definitions.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
---
_TEXT_BASE was only used by ARM to allow resolution of
symbol offsets, themselves only needed due to absolute
relocations.

In some places, _TEXT_BASE was locally defined only
to provide a literal for CONFIG_SYS_TEXT_BASE when the
latter could have been used directly.

Sometimes even, _TEXT_BASE was defined but unused.

Since all relocations in ARM are relative, offsets,
_TEXT_BASE and CONFIG_SYS_SYM_OFFSETS can be completely
removed, and their uses can be replaced with adequate
use of compiler-generated symbols from sections.c file.

 README                                      |  6 ------
 arch/arm/cpu/arm1136/start.S                | 27 ---------------------------
 arch/arm/cpu/arm1176/start.S                | 27 ---------------------------
 arch/arm/cpu/arm720t/start.S                | 26 --------------------------
 arch/arm/cpu/arm920t/start.S                | 26 --------------------------
 arch/arm/cpu/arm926ejs/at91/lowlevel_init.S | 14 +-------------
 arch/arm/cpu/arm926ejs/mxs/start.S          | 27 ---------------------------
 arch/arm/cpu/arm926ejs/start.S              | 27 ---------------------------
 arch/arm/cpu/arm946es/start.S               | 26 --------------------------
 arch/arm/cpu/arm_intcm/start.S              | 26 --------------------------
 arch/arm/cpu/armv7/omap3/lowlevel_init.S    |  3 ---
 arch/arm/cpu/armv7/start.S                  | 23 -----------------------
 arch/arm/cpu/ixp/start.S                    | 26 --------------------------
 arch/arm/cpu/pxa/start.S                    | 27 ---------------------------
 arch/arm/cpu/sa1100/start.S                 | 26 --------------------------
 arch/arm/lib/board.c                        | 12 ++++++------
 board/armltd/integrator/lowlevel_init.S     |  2 +-
 board/cm4008/flash.c                        |  2 +-
 board/cm41xx/flash.c                        |  2 +-
 board/mpl/vcma9/lowlevel_init.S             |  5 +----
 board/mx1ads/lowlevel_init.S                |  4 ----
 board/samsung/goni/lowlevel_init.S          |  3 ---
 board/samsung/smdk2410/lowlevel_init.S      |  5 +----
 board/samsung/smdk5250/lowlevel_init.S      |  5 +----
 board/samsung/smdkc100/lowlevel_init.S      |  3 ---
 board/ti/omap5912osk/lowlevel_init.S        |  4 ----
 board/ti/omap730p2/lowlevel_init.S          |  3 ---
 common/board_f.c                            | 18 +++++++-----------
 common/board_r.c                            |  4 ++--
 include/asm-generic/sections.h              | 26 +++++++-------------------
 30 files changed, 29 insertions(+), 406 deletions(-)
Albert ARIBAUD - Oct. 13, 2013, 8:03 a.m.
On Sun, 13 Oct 2013 09:10:28 +0200, Albert ARIBAUD
<albert.u.boot@aribaud.net> wrote:

> Remove the last uses of symbol offsets in ARM U-Boot.
> Remove some needless uses of _TEXT_BASE.
> Remove all _TEXT_BASE definitions.
> 
> Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
> ---
> _TEXT_BASE was only used by ARM to allow resolution of
> symbol offsets, themselves only needed due to absolute
> relocations.
> 
> In some places, _TEXT_BASE was locally defined only
> to provide a literal for CONFIG_SYS_TEXT_BASE when the
> latter could have been used directly.
> 
> Sometimes even, _TEXT_BASE was defined but unused.
> 
> Since all relocations in ARM are relative, offsets,
> _TEXT_BASE and CONFIG_SYS_SYM_OFFSETS can be completely
> removed, and their uses can be replaced with adequate
> use of compiler-generated symbols from sections.c file.

Of course, I've done some non-regression testing before submitting, but
this should undergo heavier testing by people with various ARM
hardware. Considering the changes, checks should concentrate on:

- monitor_flash_len;
- gd fields mon_len, fdt_blob, and reloc_off;
- targets the lowlevel_init.S of which was moified.

Also note two things I've noticed only after posting v1:

> diff --git a/README b/README
> index 0bb1ad5..1f9e16f 100644
> --- a/README
> +++ b/README
> @@ -3522,12 +3522,6 @@ Configuration Settings:
>  	its config.mk file). If you find problems enabling this option on
>  	your board please report the problem and send patches!
>  
> -- CONFIG_SYS_SYM_OFFSETS
> -	This is set by architectures that use offsets for link symbols
> -	instead of absolute values. So bss_start is obtained using an
> -	offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
> -	directly. You should not need to touch this setting.

The removal of CONFIG_SYS_SYM_OFFSETS from the codebase is not mentioned
in the commit message. Will add in v2.

> diff --git a/arch/arm/cpu/arm926ejs/at91/lowlevel_init.S b/arch/arm/cpu/arm926ejs/at91/lowlevel_init.S
> index 39de2f4..7d1a633 100644
> --- a/arch/arm/cpu/arm926ejs/at91/lowlevel_init.S
> +++ b/arch/arm/cpu/arm926ejs/at91/lowlevel_init.S
> @@ -26,27 +26,18 @@
>  #define CONFIG_SYS_MATRIX_EBICSA_VAL CONFIG_SYS_MATRIX_EBI0CSA_VAL
>  #endif
>  
> -_TEXT_BASE:
> -	.word	CONFIG_SYS_TEXT_BASE
> -
>  .globl lowlevel_init
>  .type lowlevel_init,function
>  lowlevel_init:
>  
> -	mov	r5, pc		/* r5 = POS1 + 4 current */
>  POS1:
> +	adr	r5, POS1	/* r5 = POS1 run time */
>  	ldr	r0, =POS1	/* r0 = POS1 compile */

This could in fact use the existing lowlevel_init label rather than
introduce POS1 for this purpose. Will fix in v2.

Amicalement,
Benoît Thébaudeau - Oct. 13, 2013, 3 p.m.
Hi Albert,

On Sunday, October 13, 2013 9:10:28 AM, Albert ARIBAUD wrote:
> Remove the last uses of symbol offsets in ARM U-Boot.
> Remove some needless uses of _TEXT_BASE.
> Remove all _TEXT_BASE definitions.
> 
> Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
> ---
> _TEXT_BASE was only used by ARM to allow resolution of
> symbol offsets, themselves only needed due to absolute
> relocations.
> 
> In some places, _TEXT_BASE was locally defined only
> to provide a literal for CONFIG_SYS_TEXT_BASE when the
> latter could have been used directly.
> 
> Sometimes even, _TEXT_BASE was defined but unused.
> 
> Since all relocations in ARM are relative, offsets,
> _TEXT_BASE and CONFIG_SYS_SYM_OFFSETS can be completely
> removed, and their uses can be replaced with adequate
> use of compiler-generated symbols from sections.c file.

[...]

> diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S
> index bd1e067..d15124b 100644
> --- a/arch/arm/cpu/arm1136/start.S
> +++ b/arch/arm/cpu/arm1136/start.S

[...]

> @@ -295,7 +269,6 @@ cpu_init_crit:
>  #ifdef CONFIG_SPL_BUILD
>  	.align	5
>  do_hang:
> -	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
>  	bl	hang				/* hang and never return */
>  #else	/* !CONFIG_SPL_BUILD */
>  	.align	5

Is this change (and the same change in the other start.S files) safe?

lib/hang.c/hang() may need a valid stack pointer because the functions that it
calls may use the stack.

When the CPU lands in do_hang, it's because some exception occurred, which may
follow a situation having corrupted sp. If sp is corrupted, the CPU won't be
able to push the exception context onto the stack, but it might still be able to
run the exception vector.

Setting sp to *_TEXT_BASE was not great, but at least this provided a few valid
words of RAM for the stack.

[...]

> diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
> index 34f50b0..f8ac573 100644
> --- a/arch/arm/lib/board.c
> +++ b/arch/arm/lib/board.c
> @@ -105,8 +105,8 @@ static int display_banner(void)
>  {
>  	printf("\n\n%s\n\n", version_string);
>  	debug("U-Boot code: %08lX -> %08lX  BSS: -> %08lX\n",
> -	       _TEXT_BASE,
> -	       _bss_start_ofs + _TEXT_BASE, _bss_end_ofs + _TEXT_BASE);
> +	       (ulong)&_start,
> +	       (ulong)&__bss_start, (ulong)&__bss_end);
>  #ifdef CONFIG_MODEM_SUPPORT
>  	debug("Modem Support enabled\n");
>  #endif

This hunk and all the other hunks using _TEXT_BASE in the same way will
introduce different resulting values than the original code for targets having
different build-time and run-time addresses.

This is not too much of an issue for the debug() call here, but this may be more
damaging for things like gd->reloc_off below.

> @@ -277,13 +277,13 @@ void board_init_f(ulong bootflag)
>  
>  	memset((void *)gd, 0, sizeof(gd_t));
>  
> -	gd->mon_len = _bss_end_ofs;
> +	gd->mon_len = (ulong)&__bss_end - (ulong)_start;
>  #ifdef CONFIG_OF_EMBED
>  	/* Get a pointer to the FDT */
>  	gd->fdt_blob = _binary_dt_dtb_start;
>  #elif defined CONFIG_OF_SEPARATE
>  	/* FDT is at end of image */
> -	gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE);
> +	gd->fdt_blob = &_end;
>  #endif
>  	/* Allow the early environment to override the fdt address */
>  	gd->fdt_blob = (void *)getenv_ulong("fdtcontroladdr", 16,
> @@ -451,7 +451,7 @@ void board_init_f(ulong bootflag)
>  
>  	gd->relocaddr = addr;
>  	gd->start_addr_sp = addr_sp;
> -	gd->reloc_off = addr - _TEXT_BASE;
> +	gd->reloc_off = addr - (ulong)&_start;
>  	debug("relocation Offset is: %08lx\n", gd->reloc_off);
>  	if (new_fdt) {
>  		memcpy(new_fdt, gd->fdt_blob, fdt_size);
> @@ -516,7 +516,7 @@ void board_init_r(gd_t *id, ulong dest_addr)
>  	gd->flags |= GD_FLG_RELOC;	/* tell others: relocation done */
>  	bootstage_mark_name(BOOTSTAGE_ID_START_UBOOT_R, "board_init_r");
>  
> -	monitor_flash_len = _end_ofs;
> +	monitor_flash_len = (ulong)&__rel_dyn_end - (ulong)_start;
>  
>  	/* Enable caches */
>  	enable_caches();

[...]

> diff --git a/common/board_f.c b/common/board_f.c
> index 0ada1af..decd7f2 100644
> --- a/common/board_f.c
> +++ b/common/board_f.c
> @@ -149,13 +149,9 @@ static int display_text_info(void)
>  #ifndef CONFIG_SANDBOX
>  	ulong bss_start, bss_end;
>  
> -#ifdef CONFIG_SYS_SYM_OFFSETS
> -	bss_start = _bss_start_ofs + _TEXT_BASE;
> -	bss_end = _bss_end_ofs + _TEXT_BASE;
> -#else
>  	bss_start = (ulong)&__bss_start;
>  	bss_end = (ulong)&__bss_end;
> -#endif
> +
>  	debug("U-Boot code: %08X -> %08lX  BSS: -> %08lX\n",
>  	      CONFIG_SYS_TEXT_BASE, bss_start, bss_end);
>  #endif

Same comment as above regarding the use of _TEXT_BASE, except that here we want
to use the runtime addresses, so the new code is more correct than the original
one, and this change is hence fine.

> @@ -275,8 +271,8 @@ static int zero_global_data(void)
>  
>  static int setup_mon_len(void)
>  {
> -#ifdef CONFIG_SYS_SYM_OFFSETS
> -	gd->mon_len = _bss_end_ofs;
> +#ifdef __ARM__
> +	gd->mon_len = (ulong)&__bss_end - (ulong)_start;
>  #elif defined(CONFIG_SANDBOX)
>  	gd->mon_len = (ulong)&_end - (ulong)_init;
>  #else
> @@ -358,11 +354,11 @@ static int setup_fdt(void)
>  	gd->fdt_blob = _binary_dt_dtb_start;
>  #elif defined CONFIG_OF_SEPARATE
>  	/* FDT is at end of image */
> -# ifdef CONFIG_SYS_SYM_OFFSETS
> -	gd->fdt_blob = (void *)(_end_ofs + CONFIG_SYS_TEXT_BASE);
> -# else
> +#ifdef CONFIG_ARM
> +	gd->fdt_blob = (ulong *)__rel_dyn_end;
> +#else
>  	gd->fdt_blob = (ulong *)&_end;
> -# endif
> +#endif
>  #elif defined(CONFIG_OF_HOSTFILE)
>  	if (read_fdt_from_file()) {
>  		puts("Failed to read control FDT\n");

There are 2 unrelated changes for gd->fdt_blob here for ARM:
 - _end_ofs + CONFIG_SYS_TEXT_BASE -> _end,
 - _end -> __rel_dyn_end.

So maybe this should be split using another patch.

> diff --git a/common/board_r.c b/common/board_r.c
> index 86ca1cb..ce84753 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -128,8 +128,8 @@ __weak int fixup_cpu(void)
>  
>  static int initr_reloc_global_data(void)
>  {
> -#ifdef CONFIG_SYS_SYM_OFFSETS
> -	monitor_flash_len = _end_ofs;
> +#ifdef __ARM__
> +	monitor_flash_len = __rel_dyn_end - __image_copy_start;
>  #elif !defined(CONFIG_SANDBOX)
>  	monitor_flash_len = (ulong)&__init_end - gd->relocaddr;
>  #endif

Ditto.

[...]

Best regards,
Benoît
Albert ARIBAUD - Oct. 13, 2013, 5:16 p.m.
Hi Benoît,

On Sun, 13 Oct 2013 17:00:25 +0200 (CEST), Benoît Thébaudeau
<benoit.thebaudeau@advansee.com> wrote:

> Hi Albert,
> 
> On Sunday, October 13, 2013 9:10:28 AM, Albert ARIBAUD wrote:
> > Remove the last uses of symbol offsets in ARM U-Boot.
> > Remove some needless uses of _TEXT_BASE.
> > Remove all _TEXT_BASE definitions.
> > 
> > Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
> > ---
> > _TEXT_BASE was only used by ARM to allow resolution of
> > symbol offsets, themselves only needed due to absolute
> > relocations.
> > 
> > In some places, _TEXT_BASE was locally defined only
> > to provide a literal for CONFIG_SYS_TEXT_BASE when the
> > latter could have been used directly.
> > 
> > Sometimes even, _TEXT_BASE was defined but unused.
> > 
> > Since all relocations in ARM are relative, offsets,
> > _TEXT_BASE and CONFIG_SYS_SYM_OFFSETS can be completely
> > removed, and their uses can be replaced with adequate
> > use of compiler-generated symbols from sections.c file.
> 
> [...]
> 
> > diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S
> > index bd1e067..d15124b 100644
> > --- a/arch/arm/cpu/arm1136/start.S
> > +++ b/arch/arm/cpu/arm1136/start.S
> 
> [...]
> 
> > @@ -295,7 +269,6 @@ cpu_init_crit:
> >  #ifdef CONFIG_SPL_BUILD
> >  	.align	5
> >  do_hang:
> > -	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
> >  	bl	hang				/* hang and never return */
> >  #else	/* !CONFIG_SPL_BUILD */
> >  	.align	5
> 
> Is this change (and the same change in the other start.S files) safe?
> 
> lib/hang.c/hang() may need a valid stack pointer because the functions that it
> calls may use the stack.
> 
> When the CPU lands in do_hang, it's because some exception occurred, which may
> follow a situation having corrupted sp. If sp is corrupted, the CPU won't be
> able to push the exception context onto the stack, but it might still be able to
> run the exception vector.
> 
> Setting sp to *_TEXT_BASE was not great, but at least this provided a few valid
> words of RAM for the stack.

Yes, there is a call to hang() which might or might not imply saving on
the stack depending on code generation, and sp might be incorrect
depending on the exception raised. I'll reintroduce the sp setting but
use the runtime value of _start as stack top. As you say, not great but
hey.

> [...]
> 
> > diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
> > index 34f50b0..f8ac573 100644
> > --- a/arch/arm/lib/board.c
> > +++ b/arch/arm/lib/board.c
> > @@ -105,8 +105,8 @@ static int display_banner(void)
> >  {
> >  	printf("\n\n%s\n\n", version_string);
> >  	debug("U-Boot code: %08lX -> %08lX  BSS: -> %08lX\n",
> > -	       _TEXT_BASE,
> > -	       _bss_start_ofs + _TEXT_BASE, _bss_end_ofs + _TEXT_BASE);
> > +	       (ulong)&_start,
> > +	       (ulong)&__bss_start, (ulong)&__bss_end);
> >  #ifdef CONFIG_MODEM_SUPPORT
> >  	debug("Modem Support enabled\n");
> >  #endif
> 
> This hunk and all the other hunks using _TEXT_BASE in the same way will
> introduce different resulting values than the original code for targets having
> different build-time and run-time addresses.
> 
> This is not too much of an issue for the debug() call here, but this may be more
> damaging for things like gd->reloc_off below.

Indeed build-time and run-time values might be different. Normally,
U-Boot starts by being loaded at its build-time address and run from
there (or directly run there if from NOR). At that point, its build- and
run-time addresses coincide. then we reach relocation. Then U-Boot
runs from top of RAM, with a run-time address different from its
build-time one, bu with all base-address-dependent locations fixed by
relocation, so again, run-time and (relocated) build-time values are
equal.

IOW, this debug() line would use true build-time values if invoked
before relocation, and actual run-time values after relocation, because
the &symbol constructs would have relocation entries and thus be fixed
during relocation.

This does not preclude corner-case situations where some in-relocation
code requires knowing both the pre- and post-relocation addresses of
a symbol; usually it's a matter of looking at the "in-RAM" U-Boot image
vs the "in-FLASH" U-Boot image, e.g. when relocating, we copy
U-Bootfrom "source" to "destination" and then fix relocation using
the "source" relocation table, because there is no "destination"
relocation table. Normally these corner-case situations only arise near
the relocation code itself.

However, if e.g. some fields of this debug() call should be the
"initial" addresses while the debug() is executed at "final" location,
just point them to me.
 
> > @@ -277,13 +277,13 @@ void board_init_f(ulong bootflag)
> >  
> >  	memset((void *)gd, 0, sizeof(gd_t));
> >  
> > -	gd->mon_len = _bss_end_ofs;
> > +	gd->mon_len = (ulong)&__bss_end - (ulong)_start;
> >  #ifdef CONFIG_OF_EMBED
> >  	/* Get a pointer to the FDT */
> >  	gd->fdt_blob = _binary_dt_dtb_start;
> >  #elif defined CONFIG_OF_SEPARATE
> >  	/* FDT is at end of image */
> > -	gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE);
> > +	gd->fdt_blob = &_end;
> >  #endif
> >  	/* Allow the early environment to override the fdt address */
> >  	gd->fdt_blob = (void *)getenv_ulong("fdtcontroladdr", 16,
> > @@ -451,7 +451,7 @@ void board_init_f(ulong bootflag)
> >  
> >  	gd->relocaddr = addr;
> >  	gd->start_addr_sp = addr_sp;
> > -	gd->reloc_off = addr - _TEXT_BASE;
> > +	gd->reloc_off = addr - (ulong)&_start;
> >  	debug("relocation Offset is: %08lx\n", gd->reloc_off);
> >  	if (new_fdt) {
> >  		memcpy(new_fdt, gd->fdt_blob, fdt_size);
> > @@ -516,7 +516,7 @@ void board_init_r(gd_t *id, ulong dest_addr)
> >  	gd->flags |= GD_FLG_RELOC;	/* tell others: relocation done */
> >  	bootstage_mark_name(BOOTSTAGE_ID_START_UBOOT_R, "board_init_r");
> >  
> > -	monitor_flash_len = _end_ofs;
> > +	monitor_flash_len = (ulong)&__rel_dyn_end - (ulong)_start;
> >  
> >  	/* Enable caches */
> >  	enable_caches();
> 
> [...]
> 
> > diff --git a/common/board_f.c b/common/board_f.c
> > index 0ada1af..decd7f2 100644
> > --- a/common/board_f.c
> > +++ b/common/board_f.c
> > @@ -149,13 +149,9 @@ static int display_text_info(void)
> >  #ifndef CONFIG_SANDBOX
> >  	ulong bss_start, bss_end;
> >  
> > -#ifdef CONFIG_SYS_SYM_OFFSETS
> > -	bss_start = _bss_start_ofs + _TEXT_BASE;
> > -	bss_end = _bss_end_ofs + _TEXT_BASE;
> > -#else
> >  	bss_start = (ulong)&__bss_start;
> >  	bss_end = (ulong)&__bss_end;
> > -#endif
> > +
> >  	debug("U-Boot code: %08X -> %08lX  BSS: -> %08lX\n",
> >  	      CONFIG_SYS_TEXT_BASE, bss_start, bss_end);
> >  #endif
> 
> Same comment as above regarding the use of _TEXT_BASE, except that here we want
> to use the runtime addresses, so the new code is more correct than the original
> one, and this change is hence fine.
> 
> > @@ -275,8 +271,8 @@ static int zero_global_data(void)
> >  
> >  static int setup_mon_len(void)
> >  {
> > -#ifdef CONFIG_SYS_SYM_OFFSETS
> > -	gd->mon_len = _bss_end_ofs;
> > +#ifdef __ARM__
> > +	gd->mon_len = (ulong)&__bss_end - (ulong)_start;
> >  #elif defined(CONFIG_SANDBOX)
> >  	gd->mon_len = (ulong)&_end - (ulong)_init;
> >  #else
> > @@ -358,11 +354,11 @@ static int setup_fdt(void)
> >  	gd->fdt_blob = _binary_dt_dtb_start;
> >  #elif defined CONFIG_OF_SEPARATE
> >  	/* FDT is at end of image */
> > -# ifdef CONFIG_SYS_SYM_OFFSETS
> > -	gd->fdt_blob = (void *)(_end_ofs + CONFIG_SYS_TEXT_BASE);
> > -# else
> > +#ifdef CONFIG_ARM
> > +	gd->fdt_blob = (ulong *)__rel_dyn_end;
> > +#else
> >  	gd->fdt_blob = (ulong *)&_end;
> > -# endif
> > +#endif
> >  #elif defined(CONFIG_OF_HOSTFILE)
> >  	if (read_fdt_from_file()) {
> >  		puts("Failed to read control FDT\n");
> 
> There are 2 unrelated changes for gd->fdt_blob here for ARM:
>  - _end_ofs + CONFIG_SYS_TEXT_BASE -> _end,
>  - _end -> __rel_dyn_end.
> 
> So maybe this should be split using another patch.

I don't think so. The switch from _end to __rel_dyn_end is done
precisely to avoid using a symbol for which an offset is needed (_end,
because linker-defined, can only have absolute relocations) and use
instead a compiler-defined, relocatable, symbol (__rel_dyn_end, compiled
from sections.c, always takes relative relocation) which does not need
an offset. This switch thus belongs in this patch.

> > diff --git a/common/board_r.c b/common/board_r.c
> > index 86ca1cb..ce84753 100644
> > --- a/common/board_r.c
> > +++ b/common/board_r.c
> > @@ -128,8 +128,8 @@ __weak int fixup_cpu(void)
> >  
> >  static int initr_reloc_global_data(void)
> >  {
> > -#ifdef CONFIG_SYS_SYM_OFFSETS
> > -	monitor_flash_len = _end_ofs;
> > +#ifdef __ARM__
> > +	monitor_flash_len = __rel_dyn_end - __image_copy_start;
> >  #elif !defined(CONFIG_SANDBOX)
> >  	monitor_flash_len = (ulong)&__init_end - gd->relocaddr;
> >  #endif
> 
> Ditto.
> 
> [...]

Thanks for your review!

> Best regards,
> Benoît

Amicalement,
Albert ARIBAUD - Oct. 14, 2013, 6:59 a.m.
On Sun, 13 Oct 2013 19:16:33 +0200, Albert ARIBAUD
<albert.u.boot@aribaud.net> wrote:

> Hi Benoît,
> 
> On Sun, 13 Oct 2013 17:00:25 +0200 (CEST), Benoît Thébaudeau
> <benoit.thebaudeau@advansee.com> wrote:
> 
> > Hi Albert,
> > 
> > On Sunday, October 13, 2013 9:10:28 AM, Albert ARIBAUD wrote:
> > > Remove the last uses of symbol offsets in ARM U-Boot.
> > > Remove some needless uses of _TEXT_BASE.
> > > Remove all _TEXT_BASE definitions.
> > > 
> > > Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
> > > ---
> > > _TEXT_BASE was only used by ARM to allow resolution of
> > > symbol offsets, themselves only needed due to absolute
> > > relocations.
> > > 
> > > In some places, _TEXT_BASE was locally defined only
> > > to provide a literal for CONFIG_SYS_TEXT_BASE when the
> > > latter could have been used directly.
> > > 
> > > Sometimes even, _TEXT_BASE was defined but unused.
> > > 
> > > Since all relocations in ARM are relative, offsets,
> > > _TEXT_BASE and CONFIG_SYS_SYM_OFFSETS can be completely
> > > removed, and their uses can be replaced with adequate
> > > use of compiler-generated symbols from sections.c file.
> > 
> > [...]
> > 
> > > diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S
> > > index bd1e067..d15124b 100644
> > > --- a/arch/arm/cpu/arm1136/start.S
> > > +++ b/arch/arm/cpu/arm1136/start.S
> > 
> > [...]
> > 
> > > @@ -295,7 +269,6 @@ cpu_init_crit:
> > >  #ifdef CONFIG_SPL_BUILD
> > >  	.align	5
> > >  do_hang:
> > > -	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
> > >  	bl	hang				/* hang and never return */
> > >  #else	/* !CONFIG_SPL_BUILD */
> > >  	.align	5
> > 
> > Is this change (and the same change in the other start.S files) safe?
> > 
> > lib/hang.c/hang() may need a valid stack pointer because the functions that it
> > calls may use the stack.
> > 
> > When the CPU lands in do_hang, it's because some exception occurred, which may
> > follow a situation having corrupted sp. If sp is corrupted, the CPU won't be
> > able to push the exception context onto the stack, but it might still be able to
> > run the exception vector.
> > 
> > Setting sp to *_TEXT_BASE was not great, but at least this provided a few valid
> > words of RAM for the stack.
> 
> Yes, there is a call to hang() which might or might not imply saving on
> the stack depending on code generation, and sp might be incorrect
> depending on the exception raised. I'll reintroduce the sp setting but
> use the runtime value of _start as stack top. As you say, not great but
> hey.

Thinking further about hangs: when we call do_hang(), by definition we
are in a critical situation where for some reason we cannot proceed
any more; and in the worst scenario, the only guaranteed valid register
we have is pc. Therefore, I'm not sure it is wise to try to do anything
else than actually hanging.

OTOH, I do understand that we may also want to do something else
than hanging, such as trying to diagnose, but we should choose more
clearly:

- either we hang for the purpose of being post-mortem-debugged from
  there, and therefore, we limit alterations to the system state as
  much as we can, by only affecting pc (to the point that 'bl hang'
  should be turned into 'b do_hang' so that lr is also preserved);

- or we want e.g. to tell the operator about it, and we make sure we
  have a correct setting, that is, we reserve and use a proper stack
  rather than set it just below _start and hope for luck.

Choosing between one or the other would be done through a configuration
option such as for instance CONFIG_SYS_LOG_HANGS.

Regarding the stack, we could use some existing exception stack, but it
might be better if it was preserved, so that its contents could be
looked into.

Comments?

Amicalement,
Benoît Thébaudeau - Oct. 14, 2013, 10:22 a.m.
Hi Albert,

On Monday, October 14, 2013 8:59:17 AM, Albert ARIBAUD wrote:
> On Sun, 13 Oct 2013 19:16:33 +0200, Albert ARIBAUD
> <albert.u.boot@aribaud.net> wrote:
> 
> > Hi Benoît,
> > 
> > On Sun, 13 Oct 2013 17:00:25 +0200 (CEST), Benoît Thébaudeau
> > <benoit.thebaudeau@advansee.com> wrote:
> > 
> > > Hi Albert,
> > > 
> > > On Sunday, October 13, 2013 9:10:28 AM, Albert ARIBAUD wrote:
> > > > Remove the last uses of symbol offsets in ARM U-Boot.
> > > > Remove some needless uses of _TEXT_BASE.
> > > > Remove all _TEXT_BASE definitions.
> > > > 
> > > > Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
> > > > ---
> > > > _TEXT_BASE was only used by ARM to allow resolution of
> > > > symbol offsets, themselves only needed due to absolute
> > > > relocations.
> > > > 
> > > > In some places, _TEXT_BASE was locally defined only
> > > > to provide a literal for CONFIG_SYS_TEXT_BASE when the
> > > > latter could have been used directly.
> > > > 
> > > > Sometimes even, _TEXT_BASE was defined but unused.
> > > > 
> > > > Since all relocations in ARM are relative, offsets,
> > > > _TEXT_BASE and CONFIG_SYS_SYM_OFFSETS can be completely
> > > > removed, and their uses can be replaced with adequate
> > > > use of compiler-generated symbols from sections.c file.
> > > 
> > > [...]
> > > 
> > > > diff --git a/arch/arm/cpu/arm1136/start.S
> > > > b/arch/arm/cpu/arm1136/start.S
> > > > index bd1e067..d15124b 100644
> > > > --- a/arch/arm/cpu/arm1136/start.S
> > > > +++ b/arch/arm/cpu/arm1136/start.S
> > > 
> > > [...]
> > > 
> > > > @@ -295,7 +269,6 @@ cpu_init_crit:
> > > >  #ifdef CONFIG_SPL_BUILD
> > > >  	.align	5
> > > >  do_hang:
> > > > -	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
> > > >  	bl	hang				/* hang and never return */
> > > >  #else	/* !CONFIG_SPL_BUILD */
> > > >  	.align	5
> > > 
> > > Is this change (and the same change in the other start.S files) safe?
> > > 
> > > lib/hang.c/hang() may need a valid stack pointer because the functions
> > > that it
> > > calls may use the stack.
> > > 
> > > When the CPU lands in do_hang, it's because some exception occurred,
> > > which may
> > > follow a situation having corrupted sp. If sp is corrupted, the CPU won't
> > > be
> > > able to push the exception context onto the stack, but it might still be
> > > able to
> > > run the exception vector.
> > > 
> > > Setting sp to *_TEXT_BASE was not great, but at least this provided a few
> > > valid
> > > words of RAM for the stack.
> > 
> > Yes, there is a call to hang() which might or might not imply saving on
> > the stack depending on code generation, and sp might be incorrect
> > depending on the exception raised. I'll reintroduce the sp setting but
> > use the runtime value of _start as stack top. As you say, not great but
> > hey.
> 
> Thinking further about hangs: when we call do_hang(), by definition we
> are in a critical situation where for some reason we cannot proceed
> any more; and in the worst scenario, the only guaranteed valid register
> we have is pc. Therefore, I'm not sure it is wise to try to do anything
> else than actually hanging.
> 
> OTOH, I do understand that we may also want to do something else
> than hanging, such as trying to diagnose, but we should choose more
> clearly:
> 
> - either we hang for the purpose of being post-mortem-debugged from
>   there, and therefore, we limit alterations to the system state as
>   much as we can, by only affecting pc (to the point that 'bl hang'
>   should be turned into 'b do_hang' so that lr is also preserved);
> 
> - or we want e.g. to tell the operator about it, and we make sure we
>   have a correct setting, that is, we reserve and use a proper stack
>   rather than set it just below _start and hope for luck.
> 
> Choosing between one or the other would be done through a configuration
> option such as for instance CONFIG_SYS_LOG_HANGS.
> 
> Regarding the stack, we could use some existing exception stack, but it
> might be better if it was preserved, so that its contents could be
> looked into.
> 
> Comments?

This configuration option would be great. The verbose log should be enabled by
default, indicating the configuration option to change in order to investigate
the hang.

In the log case, we care about having a valid stack, not about preserving the
possible exception stack contents. In the post-mortem debug case, this is the
opposite.

Best regards,
Benoît
Albert ARIBAUD - Oct. 14, 2013, 11:32 a.m.
Hi Benoît,

On Mon, 14 Oct 2013 12:22:31 +0200 (CEST), Benoît Thébaudeau
<benoit.thebaudeau@advansee.com> wrote:

> Hi Albert,
> 
> On Monday, October 14, 2013 8:59:17 AM, Albert ARIBAUD wrote:
> > On Sun, 13 Oct 2013 19:16:33 +0200, Albert ARIBAUD
> > <albert.u.boot@aribaud.net> wrote:
> > 
> > > Hi Benoît,
> > > 
> > > On Sun, 13 Oct 2013 17:00:25 +0200 (CEST), Benoît Thébaudeau
> > > <benoit.thebaudeau@advansee.com> wrote:
> > > 
> > > > Hi Albert,
> > > > 
> > > > On Sunday, October 13, 2013 9:10:28 AM, Albert ARIBAUD wrote:
> > > > > Remove the last uses of symbol offsets in ARM U-Boot.
> > > > > Remove some needless uses of _TEXT_BASE.
> > > > > Remove all _TEXT_BASE definitions.
> > > > > 
> > > > > Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
> > > > > ---
> > > > > _TEXT_BASE was only used by ARM to allow resolution of
> > > > > symbol offsets, themselves only needed due to absolute
> > > > > relocations.
> > > > > 
> > > > > In some places, _TEXT_BASE was locally defined only
> > > > > to provide a literal for CONFIG_SYS_TEXT_BASE when the
> > > > > latter could have been used directly.
> > > > > 
> > > > > Sometimes even, _TEXT_BASE was defined but unused.
> > > > > 
> > > > > Since all relocations in ARM are relative, offsets,
> > > > > _TEXT_BASE and CONFIG_SYS_SYM_OFFSETS can be completely
> > > > > removed, and their uses can be replaced with adequate
> > > > > use of compiler-generated symbols from sections.c file.
> > > > 
> > > > [...]
> > > > 
> > > > > diff --git a/arch/arm/cpu/arm1136/start.S
> > > > > b/arch/arm/cpu/arm1136/start.S
> > > > > index bd1e067..d15124b 100644
> > > > > --- a/arch/arm/cpu/arm1136/start.S
> > > > > +++ b/arch/arm/cpu/arm1136/start.S
> > > > 
> > > > [...]
> > > > 
> > > > > @@ -295,7 +269,6 @@ cpu_init_crit:
> > > > >  #ifdef CONFIG_SPL_BUILD
> > > > >  	.align	5
> > > > >  do_hang:
> > > > > -	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
> > > > >  	bl	hang				/* hang and never return */
> > > > >  #else	/* !CONFIG_SPL_BUILD */
> > > > >  	.align	5
> > > > 
> > > > Is this change (and the same change in the other start.S files) safe?
> > > > 
> > > > lib/hang.c/hang() may need a valid stack pointer because the functions
> > > > that it
> > > > calls may use the stack.
> > > > 
> > > > When the CPU lands in do_hang, it's because some exception occurred,
> > > > which may
> > > > follow a situation having corrupted sp. If sp is corrupted, the CPU won't
> > > > be
> > > > able to push the exception context onto the stack, but it might still be
> > > > able to
> > > > run the exception vector.
> > > > 
> > > > Setting sp to *_TEXT_BASE was not great, but at least this provided a few
> > > > valid
> > > > words of RAM for the stack.
> > > 
> > > Yes, there is a call to hang() which might or might not imply saving on
> > > the stack depending on code generation, and sp might be incorrect
> > > depending on the exception raised. I'll reintroduce the sp setting but
> > > use the runtime value of _start as stack top. As you say, not great but
> > > hey.
> > 
> > Thinking further about hangs: when we call do_hang(), by definition we
> > are in a critical situation where for some reason we cannot proceed
> > any more; and in the worst scenario, the only guaranteed valid register
> > we have is pc. Therefore, I'm not sure it is wise to try to do anything
> > else than actually hanging.
> > 
> > OTOH, I do understand that we may also want to do something else
> > than hanging, such as trying to diagnose, but we should choose more
> > clearly:
> > 
> > - either we hang for the purpose of being post-mortem-debugged from
> >   there, and therefore, we limit alterations to the system state as
> >   much as we can, by only affecting pc (to the point that 'bl hang'
> >   should be turned into 'b do_hang' so that lr is also preserved);
> > 
> > - or we want e.g. to tell the operator about it, and we make sure we
> >   have a correct setting, that is, we reserve and use a proper stack
> >   rather than set it just below _start and hope for luck.
> > 
> > Choosing between one or the other would be done through a configuration
> > option such as for instance CONFIG_SYS_LOG_HANGS.
> > 
> > Regarding the stack, we could use some existing exception stack, but it
> > might be better if it was preserved, so that its contents could be
> > looked into.
> > 
> > Comments?
> 
> This configuration option would be great. The verbose log should be enabled by
> default, indicating the configuration option to change in order to investigate
> the hang.

I suspect some people would argue that for SPL, the default should be
to hang rather than log.

> In the log case, we care about having a valid stack, not about preserving the
> possible exception stack contents. In the post-mortem debug case, this is the
> opposite.

Depends. You may want the log to o as faithful a state dump as feasible.

> Best regards,
> Benoît


Amicalement,
Albert ARIBAUD - Oct. 14, 2013, 11:47 a.m.
> Depends. You may want the log to o as faithful a state dump as feasible.

"...to *do* as faithful..."

Apologies,
Benoît Thébaudeau - Oct. 15, 2013, 11:07 a.m.
Hi Albert,

On Sunday, October 13, 2013 7:16:33 PM, Albert ARIBAUD wrote:
> Hi Benoît,
> 
> On Sun, 13 Oct 2013 17:00:25 +0200 (CEST), Benoît Thébaudeau
> <benoit.thebaudeau@advansee.com> wrote:
> 
> > Hi Albert,
> > 
> > On Sunday, October 13, 2013 9:10:28 AM, Albert ARIBAUD wrote:
> > [...]
> > 
> > > diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
> > > index 34f50b0..f8ac573 100644
> > > --- a/arch/arm/lib/board.c
> > > +++ b/arch/arm/lib/board.c
> > > @@ -105,8 +105,8 @@ static int display_banner(void)
> > >  {
> > >  	printf("\n\n%s\n\n", version_string);
> > >  	debug("U-Boot code: %08lX -> %08lX  BSS: -> %08lX\n",
> > > -	       _TEXT_BASE,
> > > -	       _bss_start_ofs + _TEXT_BASE, _bss_end_ofs + _TEXT_BASE);
> > > +	       (ulong)&_start,
> > > +	       (ulong)&__bss_start, (ulong)&__bss_end);
> > >  #ifdef CONFIG_MODEM_SUPPORT
> > >  	debug("Modem Support enabled\n");
> > >  #endif
> > 
> > This hunk and all the other hunks using _TEXT_BASE in the same way will
> > introduce different resulting values than the original code for targets
> > having
> > different build-time and run-time addresses.
> > 
> > This is not too much of an issue for the debug() call here, but this may be
> > more
> > damaging for things like gd->reloc_off below.
> 
> Indeed build-time and run-time values might be different. Normally,
> U-Boot starts by being loaded at its build-time address and run from
> there (or directly run there if from NOR). At that point, its build- and
> run-time addresses coincide. then we reach relocation. Then U-Boot
> runs from top of RAM, with a run-time address different from its
> build-time one, bu with all base-address-dependent locations fixed by
> relocation, so again, run-time and (relocated) build-time values are
> equal.

That's not true for all values following relocation. E.g., in start.S,
_TEXT_BASE is initialized to either CONFIG_SPL_TEXT_BASE or
CONFIG_SYS_TEXT_BASE. Those are #defined, so _TEXT_BASE has the same value
before and after relocation, and this value differs from &_start after
relocation.

> IOW, this debug() line would use true build-time values if invoked
> before relocation, and actual run-time values after relocation, because
> the &symbol constructs would have relocation entries and thus be fixed
> during relocation.
> 
> This does not preclude corner-case situations where some in-relocation
> code requires knowing both the pre- and post-relocation addresses of
> a symbol; usually it's a matter of looking at the "in-RAM" U-Boot image
> vs the "in-FLASH" U-Boot image, e.g. when relocating, we copy
> U-Bootfrom "source" to "destination" and then fix relocation using
> the "source" relocation table, because there is no "destination"
> relocation table. Normally these corner-case situations only arise near
> the relocation code itself.
> 
> However, if e.g. some fields of this debug() call should be the
> "initial" addresses while the debug() is executed at "final" location,
> just point them to me.

board_init_f() is called before relocation, so as long as there is no target
having different build- and run-time addresses at this point (which AFAIK is the
case), the changes made to this function are safe.

And display_banner() is called from board_init_f(), so everything should be fine
here.

Hence, we basically just have to make sure that there is no exception board
here.

> > > @@ -277,13 +277,13 @@ void board_init_f(ulong bootflag)
> > >  
> > >  	memset((void *)gd, 0, sizeof(gd_t));
> > >  
> > > -	gd->mon_len = _bss_end_ofs;
> > > +	gd->mon_len = (ulong)&__bss_end - (ulong)_start;
> > >  #ifdef CONFIG_OF_EMBED
> > >  	/* Get a pointer to the FDT */
> > >  	gd->fdt_blob = _binary_dt_dtb_start;
> > >  #elif defined CONFIG_OF_SEPARATE
> > >  	/* FDT is at end of image */
> > > -	gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE);
> > > +	gd->fdt_blob = &_end;
> > >  #endif
> > >  	/* Allow the early environment to override the fdt address */
> > >  	gd->fdt_blob = (void *)getenv_ulong("fdtcontroladdr", 16,
> > > @@ -451,7 +451,7 @@ void board_init_f(ulong bootflag)
> > >  
> > >  	gd->relocaddr = addr;
> > >  	gd->start_addr_sp = addr_sp;
> > > -	gd->reloc_off = addr - _TEXT_BASE;
> > > +	gd->reloc_off = addr - (ulong)&_start;
> > >  	debug("relocation Offset is: %08lx\n", gd->reloc_off);
> > >  	if (new_fdt) {
> > >  		memcpy(new_fdt, gd->fdt_blob, fdt_size);
> > > @@ -516,7 +516,7 @@ void board_init_r(gd_t *id, ulong dest_addr)
> > >  	gd->flags |= GD_FLG_RELOC;	/* tell others: relocation done */
> > >  	bootstage_mark_name(BOOTSTAGE_ID_START_UBOOT_R, "board_init_r");
> > >  
> > > -	monitor_flash_len = _end_ofs;
> > > +	monitor_flash_len = (ulong)&__rel_dyn_end - (ulong)_start;
> > >  
> > >  	/* Enable caches */
> > >  	enable_caches();
> > 
> > [...]

Best regards,
Benoît
Albert ARIBAUD - Oct. 15, 2013, 11:21 a.m.
Hi Benoît,

On Tue, 15 Oct 2013 13:07:53 +0200 (CEST), Benoît Thébaudeau
<benoit.thebaudeau@advansee.com> wrote:

> Hi Albert,
> 
> On Sunday, October 13, 2013 7:16:33 PM, Albert ARIBAUD wrote:
> > Hi Benoît,
> > 
> > On Sun, 13 Oct 2013 17:00:25 +0200 (CEST), Benoît Thébaudeau
> > <benoit.thebaudeau@advansee.com> wrote:
> > 
> > > Hi Albert,
> > > 
> > > On Sunday, October 13, 2013 9:10:28 AM, Albert ARIBAUD wrote:
> > > [...]
> > > 
> > > > diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
> > > > index 34f50b0..f8ac573 100644
> > > > --- a/arch/arm/lib/board.c
> > > > +++ b/arch/arm/lib/board.c
> > > > @@ -105,8 +105,8 @@ static int display_banner(void)
> > > >  {
> > > >  	printf("\n\n%s\n\n", version_string);
> > > >  	debug("U-Boot code: %08lX -> %08lX  BSS: -> %08lX\n",
> > > > -	       _TEXT_BASE,
> > > > -	       _bss_start_ofs + _TEXT_BASE, _bss_end_ofs + _TEXT_BASE);
> > > > +	       (ulong)&_start,
> > > > +	       (ulong)&__bss_start, (ulong)&__bss_end);
> > > >  #ifdef CONFIG_MODEM_SUPPORT
> > > >  	debug("Modem Support enabled\n");
> > > >  #endif
> > > 
> > > This hunk and all the other hunks using _TEXT_BASE in the same way will
> > > introduce different resulting values than the original code for targets
> > > having
> > > different build-time and run-time addresses.
> > > 
> > > This is not too much of an issue for the debug() call here, but this may be
> > > more
> > > damaging for things like gd->reloc_off below.
> > 
> > Indeed build-time and run-time values might be different. Normally,
> > U-Boot starts by being loaded at its build-time address and run from
> > there (or directly run there if from NOR). At that point, its build- and
> > run-time addresses coincide. then we reach relocation. Then U-Boot
> > runs from top of RAM, with a run-time address different from its
> > build-time one, bu with all base-address-dependent locations fixed by
> > relocation, so again, run-time and (relocated) build-time values are
> > equal.
> 
> That's not true for all values following relocation. E.g., in start.S,
> _TEXT_BASE is initialized to either CONFIG_SPL_TEXT_BASE or
> CONFIG_SYS_TEXT_BASE. Those are #defined, so _TEXT_BASE has the same value
> before and after relocation, and this value differs from &_start after
> relocation.

Indeed; however, I believe that in all cases where _TEXT_BASE contained
CONFIG_{SYS,SPL}_TEXT_BASE, I replaced references to _TEXT_BASE with
references to CONFIG_{SYS,SPL}_TEXT_BASE, which is a constant and thus
will not be relocated. Unless I missed one, of course.

Similarly, in places where relocation-sensitive symbols are actually
used to compute size, which is relocation-insensitive, we should not
have any problems either.

> > IOW, this debug() line would use true build-time values if invoked
> > before relocation, and actual run-time values after relocation, because
> > the &symbol constructs would have relocation entries and thus be fixed
> > during relocation.
> > 
> > This does not preclude corner-case situations where some in-relocation
> > code requires knowing both the pre- and post-relocation addresses of
> > a symbol; usually it's a matter of looking at the "in-RAM" U-Boot image
> > vs the "in-FLASH" U-Boot image, e.g. when relocating, we copy
> > U-Bootfrom "source" to "destination" and then fix relocation using
> > the "source" relocation table, because there is no "destination"
> > relocation table. Normally these corner-case situations only arise near
> > the relocation code itself.
> > 
> > However, if e.g. some fields of this debug() call should be the
> > "initial" addresses while the debug() is executed at "final" location,
> > just point them to me.
> 
> board_init_f() is called before relocation, so as long as there is no target
> having different build- and run-time addresses at this point (which AFAIK is the
> case), the changes made to this function are safe.
> 
> And display_banner() is called from board_init_f(), so everything should be fine
> here.
> 
> Hence, we basically just have to make sure that there is no exception board
> here.

Agreed, although the only possible 'exception' would be some board code
expecting relocation-sensitive symbols to keep their pre-relocation
values after relocation, and I don't see why that would happen.

Thanks for your input.

> Best regards,
> Benoît

Amicalement,
Albert ARIBAUD - Oct. 15, 2013, 12:04 p.m.
On Sun, 13 Oct 2013 19:16:33 +0200, Albert ARIBAUD
<albert.u.boot@aribaud.net> wrote:

> I don't think so. The switch from _end to __rel_dyn_end is done
> precisely to avoid using a symbol for which an offset is needed (_end,
> because linker-defined, can only have absolute relocations) and use
> instead a compiler-defined, relocatable, symbol (__rel_dyn_end, compiled
> from sections.c, always takes relative relocation) which does not need
> an offset. This switch thus belongs in this patch.

Actually, _end could be made a compiler-generated symbol too. This
would be more consistent with what is done with the BSS and image start
and end symbols, and would allow keeping _end here. Will revert change
here and send v2 as a two-patch series as you suggest.

> Amicalement,

Amicalement,

Patch

diff --git a/README b/README
index 0bb1ad5..1f9e16f 100644
--- a/README
+++ b/README
@@ -3522,12 +3522,6 @@  Configuration Settings:
 	its config.mk file). If you find problems enabling this option on
 	your board please report the problem and send patches!
 
-- CONFIG_SYS_SYM_OFFSETS
-	This is set by architectures that use offsets for link symbols
-	instead of absolute values. So bss_start is obtained using an
-	offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
-	directly. You should not need to touch this setting.
-
 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
 	This is set by OMAP boards for the max time that reset should
 	be asserted. See doc/README.omap-reset-time for details on how
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S
index bd1e067..d15124b 100644
--- a/arch/arm/cpu/arm1136/start.S
+++ b/arch/arm/cpu/arm1136/start.S
@@ -70,32 +70,6 @@  _end_vect:
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
@@ -295,7 +269,6 @@  cpu_init_crit:
 #ifdef CONFIG_SPL_BUILD
 	.align	5
 do_hang:
-	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
 	bl	hang				/* hang and never return */
 #else	/* !CONFIG_SPL_BUILD */
 	.align	5
diff --git a/arch/arm/cpu/arm1176/start.S b/arch/arm/cpu/arm1176/start.S
index ffd7dd0..ce62011 100644
--- a/arch/arm/cpu/arm1176/start.S
+++ b/arch/arm/cpu/arm1176/start.S
@@ -77,33 +77,6 @@  _end_vect:
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 /* IRQ stack memory (calculated at run-time) + 8 bytes */
 .globl IRQ_STACK_START_IN
 IRQ_STACK_START_IN:
diff --git a/arch/arm/cpu/arm720t/start.S b/arch/arm/cpu/arm720t/start.S
index b6bfacf..e167e4c 100644
--- a/arch/arm/cpu/arm720t/start.S
+++ b/arch/arm/cpu/arm720t/start.S
@@ -67,32 +67,6 @@  _pad:			.word 0x12345678 /* now 16*4=64 */
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
diff --git a/arch/arm/cpu/arm920t/start.S b/arch/arm/cpu/arm920t/start.S
index a67b659..7bf094a 100644
--- a/arch/arm/cpu/arm920t/start.S
+++ b/arch/arm/cpu/arm920t/start.S
@@ -55,32 +55,6 @@  _fiq:			.word fiq
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
diff --git a/arch/arm/cpu/arm926ejs/at91/lowlevel_init.S b/arch/arm/cpu/arm926ejs/at91/lowlevel_init.S
index 39de2f4..7d1a633 100644
--- a/arch/arm/cpu/arm926ejs/at91/lowlevel_init.S
+++ b/arch/arm/cpu/arm926ejs/at91/lowlevel_init.S
@@ -26,27 +26,18 @@ 
 #define CONFIG_SYS_MATRIX_EBICSA_VAL CONFIG_SYS_MATRIX_EBI0CSA_VAL
 #endif
 
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE
-
 .globl lowlevel_init
 .type lowlevel_init,function
 lowlevel_init:
 
-	mov	r5, pc		/* r5 = POS1 + 4 current */
 POS1:
+	adr	r5, POS1	/* r5 = POS1 run time */
 	ldr	r0, =POS1	/* r0 = POS1 compile */
-	ldr	r2, _TEXT_BASE
-	sub	r0, r0, r2	/* r0 = POS1-_TEXT_BASE (POS1 relative) */
 	sub	r5, r5, r0	/* r0 = CONFIG_SYS_TEXT_BASE-1 */
-	sub	r5, r5, #4	/* r1 = text base - current */
 
 	/* memory control configuration 1 */
 	ldr	r0, =SMRDATA
 	ldr	r2, =SMRDATA1
-	ldr	r1, _TEXT_BASE
-	sub	r0, r0, r1
-	sub	r2, r2, r1
 	add	r0, r0, r5
 	add	r2, r2, r5
 0:
@@ -149,9 +140,6 @@  PLL_setup_end:
 
 	ldr	r0, =SMRDATA1
 	ldr	r2, =SMRDATA2
-	ldr	r1, _TEXT_BASE
-	sub	r0, r0, r1
-	sub	r2, r2, r1
 	add	r0, r0, r5
 	add	r2, r2, r5
 2:
diff --git a/arch/arm/cpu/arm926ejs/mxs/start.S b/arch/arm/cpu/arm926ejs/mxs/start.S
index 3e454ae..f06a9ca 100644
--- a/arch/arm/cpu/arm926ejs/mxs/start.S
+++ b/arch/arm/cpu/arm926ejs/mxs/start.S
@@ -101,32 +101,6 @@  fiq:
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#ifdef CONFIG_SPL_TEXT_BASE
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
@@ -198,6 +172,5 @@  _reset:
 	bx	lr
 
 _hang:
-	ldr	sp, _TEXT_BASE			/* switch to abort stack */
 1:
 	bl	1b				/* hang and never return */
diff --git a/arch/arm/cpu/arm926ejs/start.S b/arch/arm/cpu/arm926ejs/start.S
index 5360f55..0717327 100644
--- a/arch/arm/cpu/arm926ejs/start.S
+++ b/arch/arm/cpu/arm926ejs/start.S
@@ -102,32 +102,6 @@  _fiq:
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
@@ -330,7 +304,6 @@  flush_dcache:
 #ifdef CONFIG_SPL_BUILD
 	.align	5
 do_hang:
-	ldr	sp, _TEXT_BASE			/* switch to abort stack */
 1:
 	bl	1b				/* hang and never return */
 #else	/* !CONFIG_SPL_BUILD */
diff --git a/arch/arm/cpu/arm946es/start.S b/arch/arm/cpu/arm946es/start.S
index e16b088..7d50145 100644
--- a/arch/arm/cpu/arm946es/start.S
+++ b/arch/arm/cpu/arm946es/start.S
@@ -71,32 +71,6 @@  _vectors_end:
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
diff --git a/arch/arm/cpu/arm_intcm/start.S b/arch/arm/cpu/arm_intcm/start.S
index 5783df1..7404ea7 100644
--- a/arch/arm/cpu/arm_intcm/start.S
+++ b/arch/arm/cpu/arm_intcm/start.S
@@ -67,32 +67,6 @@  _fiq:
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
diff --git a/arch/arm/cpu/armv7/omap3/lowlevel_init.S b/arch/arm/cpu/armv7/omap3/lowlevel_init.S
index 6f7261b..78577b1 100644
--- a/arch/arm/cpu/armv7/omap3/lowlevel_init.S
+++ b/arch/arm/cpu/armv7/omap3/lowlevel_init.S
@@ -17,9 +17,6 @@ 
 #include <asm/arch/clocks_omap3.h>
 #include <linux/linkage.h>
 
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE	/* sdram load addr from config.mk */
-
 #ifdef CONFIG_SPL_BUILD
 ENTRY(save_boot_params)
 	ldr	r4, =omap3_boot_device
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index ef62fc8..a5c749b 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -63,29 +63,6 @@  _end_vect:
  *
  *************************************************************************/
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
diff --git a/arch/arm/cpu/ixp/start.S b/arch/arm/cpu/ixp/start.S
index 1362234..7a34a39 100644
--- a/arch/arm/cpu/ixp/start.S
+++ b/arch/arm/cpu/ixp/start.S
@@ -80,32 +80,6 @@  _fiq:			.word fiq
  * - jump to second stage
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
diff --git a/arch/arm/cpu/pxa/start.S b/arch/arm/cpu/pxa/start.S
index 303ca84..5d33788 100644
--- a/arch/arm/cpu/pxa/start.S
+++ b/arch/arm/cpu/pxa/start.S
@@ -84,32 +84,6 @@  _end_vect:
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
@@ -316,7 +290,6 @@  cpu_init_crit:
 #ifdef CONFIG_SPL_BUILD
 	.align	5
 do_hang:
-	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
 	bl	hang				/* hang and never return */
 #else	/* !CONFIG_SPL_BUILD */
 	.align	5
diff --git a/arch/arm/cpu/sa1100/start.S b/arch/arm/cpu/sa1100/start.S
index 27bcda5..bf80937 100644
--- a/arch/arm/cpu/sa1100/start.S
+++ b/arch/arm/cpu/sa1100/start.S
@@ -56,32 +56,6 @@  _fiq:			.word fiq
  *************************************************************************
  */
 
-.globl _TEXT_BASE
-_TEXT_BASE:
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
-	.word	CONFIG_SPL_TEXT_BASE
-#else
-	.word	CONFIG_SYS_TEXT_BASE
-#endif
-
-/*
- * These are defined in the board-specific linker script.
- * Subtracting _start from them lets the linker put their
- * relative position in the executable instead of leaving
- * them null.
- */
-.globl _bss_start_ofs
-_bss_start_ofs:
-	.word __bss_start - _start
-
-.globl _bss_end_ofs
-_bss_end_ofs:
-	.word __bss_end - _start
-
-.globl _end_ofs
-_end_ofs:
-	.word _end - _start
-
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
 .globl IRQ_STACK_START
diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
index 34f50b0..f8ac573 100644
--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -105,8 +105,8 @@  static int display_banner(void)
 {
 	printf("\n\n%s\n\n", version_string);
 	debug("U-Boot code: %08lX -> %08lX  BSS: -> %08lX\n",
-	       _TEXT_BASE,
-	       _bss_start_ofs + _TEXT_BASE, _bss_end_ofs + _TEXT_BASE);
+	       (ulong)&_start,
+	       (ulong)&__bss_start, (ulong)&__bss_end);
 #ifdef CONFIG_MODEM_SUPPORT
 	debug("Modem Support enabled\n");
 #endif
@@ -277,13 +277,13 @@  void board_init_f(ulong bootflag)
 
 	memset((void *)gd, 0, sizeof(gd_t));
 
-	gd->mon_len = _bss_end_ofs;
+	gd->mon_len = (ulong)&__bss_end - (ulong)_start;
 #ifdef CONFIG_OF_EMBED
 	/* Get a pointer to the FDT */
 	gd->fdt_blob = _binary_dt_dtb_start;
 #elif defined CONFIG_OF_SEPARATE
 	/* FDT is at end of image */
-	gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE);
+	gd->fdt_blob = &_end;
 #endif
 	/* Allow the early environment to override the fdt address */
 	gd->fdt_blob = (void *)getenv_ulong("fdtcontroladdr", 16,
@@ -451,7 +451,7 @@  void board_init_f(ulong bootflag)
 
 	gd->relocaddr = addr;
 	gd->start_addr_sp = addr_sp;
-	gd->reloc_off = addr - _TEXT_BASE;
+	gd->reloc_off = addr - (ulong)&_start;
 	debug("relocation Offset is: %08lx\n", gd->reloc_off);
 	if (new_fdt) {
 		memcpy(new_fdt, gd->fdt_blob, fdt_size);
@@ -516,7 +516,7 @@  void board_init_r(gd_t *id, ulong dest_addr)
 	gd->flags |= GD_FLG_RELOC;	/* tell others: relocation done */
 	bootstage_mark_name(BOOTSTAGE_ID_START_UBOOT_R, "board_init_r");
 
-	monitor_flash_len = _end_ofs;
+	monitor_flash_len = (ulong)&__rel_dyn_end - (ulong)_start;
 
 	/* Enable caches */
 	enable_caches();
diff --git a/board/armltd/integrator/lowlevel_init.S b/board/armltd/integrator/lowlevel_init.S
index 4e2da40..27cf054 100644
--- a/board/armltd/integrator/lowlevel_init.S
+++ b/board/armltd/integrator/lowlevel_init.S
@@ -183,7 +183,7 @@  cm_remap:
 
 	/* Now 0x00000000 is writeable, replace the vectors	*/
 	ldr	r0, =_start	/* r0 <- start of vectors	*/
-	ldr	r2, =_TEXT_BASE	/* r2 <- past vectors	*/
+	add	r2, r0, #64	/* r2 <- past vectors	*/
 	sub	r1,r1,r1		/* destination 0x00000000	*/
 
 copy_vec:
diff --git a/board/cm4008/flash.c b/board/cm4008/flash.c
index 2511928..8315a57 100644
--- a/board/cm4008/flash.c
+++ b/board/cm4008/flash.c
@@ -57,7 +57,7 @@  unsigned long flash_init (void)
 	 */
 	flash_protect (FLAG_PROTECT_SET,
 		       CONFIG_SYS_FLASH_BASE,
-		       CONFIG_SYS_FLASH_BASE + _bss_start_ofs,
+		       CONFIG_SYS_FLASH_BASE + (__bss_end - __bss_start),
 		       &flash_info[0]);
 
 	return size;
diff --git a/board/cm41xx/flash.c b/board/cm41xx/flash.c
index 2511928..8315a57 100644
--- a/board/cm41xx/flash.c
+++ b/board/cm41xx/flash.c
@@ -57,7 +57,7 @@  unsigned long flash_init (void)
 	 */
 	flash_protect (FLAG_PROTECT_SET,
 		       CONFIG_SYS_FLASH_BASE,
-		       CONFIG_SYS_FLASH_BASE + _bss_start_ofs,
+		       CONFIG_SYS_FLASH_BASE + (__bss_end - __bss_start),
 		       &flash_info[0]);
 
 	return size;
diff --git a/board/mpl/vcma9/lowlevel_init.S b/board/mpl/vcma9/lowlevel_init.S
index b889cf9..cca9c0c 100644
--- a/board/mpl/vcma9/lowlevel_init.S
+++ b/board/mpl/vcma9/lowlevel_init.S
@@ -197,13 +197,10 @@ 
 #define REFCNT_266		0
 /**************************************/
 
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE
-
 .globl lowlevel_init
 lowlevel_init:
 	/* use r0 to relocate DATA read/write to flash rather than memory ! */
-	ldr	r0, _TEXT_BASE
+	ldr	r0, =CONFIG_SYS_TEXT_BASE
 	ldr	r13, =BWSCON
 
 	/* enable minimal access to PLD */
diff --git a/board/mx1ads/lowlevel_init.S b/board/mx1ads/lowlevel_init.S
index d1e472a..3e713cc 100644
--- a/board/mx1ads/lowlevel_init.S
+++ b/board/mx1ads/lowlevel_init.S
@@ -16,10 +16,6 @@ 
 #define SDCTL0			0x221000
 #define SDCTL1			0x221004
 
-
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE
-
 .globl lowlevel_init
 lowlevel_init:
 /* memory controller init		*/
diff --git a/board/samsung/goni/lowlevel_init.S b/board/samsung/goni/lowlevel_init.S
index 726211a..d52bc09 100644
--- a/board/samsung/goni/lowlevel_init.S
+++ b/board/samsung/goni/lowlevel_init.S
@@ -22,9 +22,6 @@ 
  * r9 has Mobile DDR size, 1 means 1GiB, 2 means 2GiB and so on
  */
 
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE
-
 	.globl lowlevel_init
 lowlevel_init:
 	mov	r11, lr
diff --git a/board/samsung/smdk2410/lowlevel_init.S b/board/samsung/smdk2410/lowlevel_init.S
index c7b78fd..5de04f1 100644
--- a/board/samsung/smdk2410/lowlevel_init.S
+++ b/board/samsung/smdk2410/lowlevel_init.S
@@ -110,16 +110,13 @@ 
 #define REFCNT			1113	/* period=15.6us, HCLK=60Mhz, (2048+1-15.6*60) */
 /**************************************/
 
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE
-
 .globl lowlevel_init
 lowlevel_init:
 	/* memory control configuration */
 	/* make r0 relative the current location so that it */
 	/* reads SMRDATA out of FLASH rather than memory ! */
 	ldr     r0, =SMRDATA
-	ldr	r1, _TEXT_BASE
+	ldr	r1, =CONFIG_SYS_TEXT_BASE
 	sub	r0, r0, r1
 	ldr	r1, =BWSCON	/* Bus Width Status Controller */
 	add     r2, r0, #13*4
diff --git a/board/samsung/smdk5250/lowlevel_init.S b/board/samsung/smdk5250/lowlevel_init.S
index 9003e2d..8e389cc 100644
--- a/board/samsung/smdk5250/lowlevel_init.S
+++ b/board/samsung/smdk5250/lowlevel_init.S
@@ -10,9 +10,6 @@ 
 #include <version.h>
 #include <asm/arch/cpu.h>
 
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE
-
 	.globl lowlevel_init
 lowlevel_init:
 
@@ -47,7 +44,7 @@  lowlevel_init:
 	ldr	r0, =0x0ffffff		/* r0 <- Mask Bits*/
 	bic	r1, pc, r0		/* pc <- current addr of code */
 					/* r1 <- unmasked bits of pc */
-	ldr	r2, _TEXT_BASE		/* r2 <- original base addr in ram */
+	ldr	r2, =CONFIG_SYS_TEXT_BASE /* r2 <- original base addr in ram */
 	bic	r2, r2, r0		/* r2 <- unmasked bits of r2*/
 	cmp	r1, r2			/* compare r1, r2 */
 	beq	1f			/* r0 == r1 then skip sdram init */
diff --git a/board/samsung/smdkc100/lowlevel_init.S b/board/samsung/smdkc100/lowlevel_init.S
index 4df0974..65e6b7a 100644
--- a/board/samsung/smdkc100/lowlevel_init.S
+++ b/board/samsung/smdkc100/lowlevel_init.S
@@ -17,9 +17,6 @@ 
  * r5 has zero always
  */
 
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE
-
 	.globl lowlevel_init
 lowlevel_init:
 	mov	r9, lr
diff --git a/board/ti/omap5912osk/lowlevel_init.S b/board/ti/omap5912osk/lowlevel_init.S
index cad0a5a..e05a1c7 100644
--- a/board/ti/omap5912osk/lowlevel_init.S
+++ b/board/ti/omap5912osk/lowlevel_init.S
@@ -18,10 +18,6 @@ 
 #include <./configs/omap1510.h>
 #endif
 
-
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE	/* sdram load addr from config.mk */
-
 .globl lowlevel_init
 lowlevel_init:
 
diff --git a/board/ti/omap730p2/lowlevel_init.S b/board/ti/omap730p2/lowlevel_init.S
index 795c495..c7ea21b 100644
--- a/board/ti/omap730p2/lowlevel_init.S
+++ b/board/ti/omap730p2/lowlevel_init.S
@@ -24,9 +24,6 @@ 
 #include <./configs/omap730.h>
 #endif
 
-_TEXT_BASE:
-	.word	CONFIG_SYS_TEXT_BASE	/* sdram load addr from config.mk */
-
 .globl lowlevel_init
 lowlevel_init:
 	/* Save callers address in r11 - r11 must never be modified */
diff --git a/common/board_f.c b/common/board_f.c
index 0ada1af..decd7f2 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -149,13 +149,9 @@  static int display_text_info(void)
 #ifndef CONFIG_SANDBOX
 	ulong bss_start, bss_end;
 
-#ifdef CONFIG_SYS_SYM_OFFSETS
-	bss_start = _bss_start_ofs + _TEXT_BASE;
-	bss_end = _bss_end_ofs + _TEXT_BASE;
-#else
 	bss_start = (ulong)&__bss_start;
 	bss_end = (ulong)&__bss_end;
-#endif
+
 	debug("U-Boot code: %08X -> %08lX  BSS: -> %08lX\n",
 	      CONFIG_SYS_TEXT_BASE, bss_start, bss_end);
 #endif
@@ -275,8 +271,8 @@  static int zero_global_data(void)
 
 static int setup_mon_len(void)
 {
-#ifdef CONFIG_SYS_SYM_OFFSETS
-	gd->mon_len = _bss_end_ofs;
+#ifdef __ARM__
+	gd->mon_len = (ulong)&__bss_end - (ulong)_start;
 #elif defined(CONFIG_SANDBOX)
 	gd->mon_len = (ulong)&_end - (ulong)_init;
 #else
@@ -358,11 +354,11 @@  static int setup_fdt(void)
 	gd->fdt_blob = _binary_dt_dtb_start;
 #elif defined CONFIG_OF_SEPARATE
 	/* FDT is at end of image */
-# ifdef CONFIG_SYS_SYM_OFFSETS
-	gd->fdt_blob = (void *)(_end_ofs + CONFIG_SYS_TEXT_BASE);
-# else
+#ifdef CONFIG_ARM
+	gd->fdt_blob = (ulong *)__rel_dyn_end;
+#else
 	gd->fdt_blob = (ulong *)&_end;
-# endif
+#endif
 #elif defined(CONFIG_OF_HOSTFILE)
 	if (read_fdt_from_file()) {
 		puts("Failed to read control FDT\n");
diff --git a/common/board_r.c b/common/board_r.c
index 86ca1cb..ce84753 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -128,8 +128,8 @@  __weak int fixup_cpu(void)
 
 static int initr_reloc_global_data(void)
 {
-#ifdef CONFIG_SYS_SYM_OFFSETS
-	monitor_flash_len = _end_ofs;
+#ifdef __ARM__
+	monitor_flash_len = __rel_dyn_end - __image_copy_start;
 #elif !defined(CONFIG_SANDBOX)
 	monitor_flash_len = (ulong)&__init_end - gd->relocaddr;
 #endif
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 7e1eb4b..458952f 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -63,28 +63,16 @@  extern char __image_copy_end[];
 extern void _start(void);
 
 /*
- * ARM needs to use offsets for symbols, since the values of some symbols
- * are not resolved prior to relocation (and are just 0). Maybe this can be
- * resolved, or maybe other architectures are similar, iwc this should be
- * promoted to an architecture option.
+ * ARM defines its symbols as char[]. Other arches define them as ulongs.
  */
 #ifdef CONFIG_ARM
-#define CONFIG_SYS_SYM_OFFSETS
-#endif
-
-#ifdef CONFIG_SYS_SYM_OFFSETS
-/* Start/end of the relocation entries, as an offset from _start */
-extern ulong _rel_dyn_start_ofs;
-extern ulong _rel_dyn_end_ofs;
-
-/* End of the region to be relocated, as an offset form _start */
-extern ulong _image_copy_end_ofs;
 
-extern ulong _bss_start_ofs;	/* BSS start relative to _start */
-extern ulong _bss_end_ofs;		/* BSS end relative to _start */
-extern ulong _end_ofs;		/* end of image relative to _start */
-
-extern ulong _TEXT_BASE;	/* code start */
+extern char __bss_start[];
+extern char __bss_end[];
+extern char __image_copy_start[];
+extern char __image_copy_end[];
+extern char __rel_dyn_start[];
+extern char __rel_dyn_end[];
 
 #else /* don't use offsets: */