Hi Albert, On Friday, April 5, 2013 8:00:43 AM, Albert ARIBAUD wrote: > Hi Benoît, > > CC:ing Stephen Warren who wrote commit 2b7818d4 which git blame tells > me added the ASSERT() to arch/arm/cpu/u-boot.lds, and Tom Rini to help > decide what to do. > > On Fri, 5 Apr 2013 05:44:55 +0200 (CEST), Benoît Thébaudeau > <benoit.thebaud...@advansee.com> wrote: > > > Hi Albert, > > > > On Friday, April 5, 2013 1:54:38 AM, Albert ARIBAUD wrote: > > > Hi Benoît, > > > > > > On Fri, 5 Apr 2013 01:13:51 +0200 (CEST), Benoît Thébaudeau > > > <benoit.thebaud...@advansee.com> wrote: > > > > > > > On Friday, April 5, 2013 1:05:53 AM, Benoît Thébaudeau wrote: > > > > > Hi Albert, > > > > > > > > > > On Friday, April 5, 2013 12:13:53 AM, Albert ARIBAUD wrote: > > > > > > Subject: [PATCH] ARM: Fix __bss_start and __bss_end in linker > > > > > > scripts > > > > > > > > > > > > Commit 3ebd1cbc introduced compiler-generated __bss_start > > > > > > and __bss_end__ and commit c23561e7 rewrote all __bss_end__ > > > > > > as __bss_end. Their merge caused silent and harmless but > > > > > > potentially bug-inducing clashes between compiler- and linker- > > > > > > enerated __bss_end symbols. > > > > > > > > > > > > Make __bss_end and __bss_start compiler-only, and create > > > > > > __bss_base and __bss_limit for linker-only use. > > > > > > > > > > > > Reported-by: Benoît Thébaudeau <benoit.thebaud...@advansee.com> > > > > > > Signed-off-by: Albert ARIBAUD <albert.u.b...@aribaud.net> > > > > > > --- > > > > > > arch/arm/cpu/ixp/u-boot.lds | 14 ++++++++++---- > > > > > > arch/arm/cpu/u-boot.lds | 14 ++++++++++---- > > > > > > board/actux1/u-boot.lds | 14 ++++++++++---- > > > > > > board/actux2/u-boot.lds | 14 ++++++++++---- > > > > > > board/actux3/u-boot.lds | 14 ++++++++++---- > > > > > > board/dvlhost/u-boot.lds | 14 ++++++++++---- > > > > > > board/freescale/mx31ads/u-boot.lds | 14 ++++++++++---- > > > > > > 7 files changed, 70 insertions(+), 28 deletions(-) > > > > > > > > > > > > diff --git a/arch/arm/cpu/ixp/u-boot.lds > > > > > > b/arch/arm/cpu/ixp/u-boot.lds > > > > > > index 8345b55..c999829 100644 > > > > > > --- a/arch/arm/cpu/ixp/u-boot.lds > > > > > > +++ b/arch/arm/cpu/ixp/u-boot.lds > > > > > > @@ -67,17 +67,23 @@ SECTIONS > > > > > > > > > > > > _end = .; > > > > > > > > > > > > +/* > > > > > > + * Compiler-generated __bss_start and __bss_end, see > > > > > > arch/arm/lib/bss.c > > > > > > + * __bss_base and __bss_limit are for linker only (overlay > > > > > > ordering) > > > > > > + */ > > > > > > + > > > > > > .bss_start __rel_dyn_start (OVERLAY) : { > > > > > > KEEP(*(.__bss_start)); > > > > > > + HIDDEN(__bss_base = .); > > > > > > } > > > > > > > > > > > > - .bss __bss_start (OVERLAY) : { > > > > > > + .bss __bss_base (OVERLAY) : { > > > > > > *(.bss*) > > > > > > . = ALIGN(4); > > > > > > - __bss_end = .; > > > > > > + HIDDEN(__bss_limit = .); > > > > > > } > > > > > > - .bss_end __bss_end (OVERLAY) : { > > > > > > - KEEP(*(__bss_end)); > > > > > > + .bss_end __bss_limit (OVERLAY) : { > > > > > > + KEEP(*(.__bss_end)); > > > > > > } > > > > > > > > > > > > /DISCARD/ : { *(.dynstr*) } > > > > > > diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds > > > > > > index 3a1083d..0543b06 100644 > > > > > > --- a/arch/arm/cpu/u-boot.lds > > > > > > +++ b/arch/arm/cpu/u-boot.lds > > > > > > @@ -81,18 +81,24 @@ SECTIONS > > > > > > *(.mmutable) > > > > > > } > > > > > > > > > > > > +/* > > > > > > + * Compiler-generated __bss_start and __bss_end, see > > > > > > arch/arm/lib/bss.c > > > > > > + * __bss_base and __bss_limit are for linker only (overlay > > > > > > ordering) > > > > > > + */ > > > > > > + > > > > > > .bss_start __rel_dyn_start (OVERLAY) : { > > > > > > KEEP(*(.__bss_start)); > > > > > > + HIDDEN(__bss_base = .); > > > > > > } > > > > > > > > > > > > - .bss __bss_start (OVERLAY) : { > > > > > > + .bss __bss_base (OVERLAY) : { > > > > > > *(.bss*) > > > > > > . = ALIGN(4); > > > > > > - __bss_end = .; > > > > > > + HIDDEN(__bss_limit = .); > > > > > > } > > > > > > > > > > > > - .bss_end __bss_end (OVERLAY) : { > > > > > > - KEEP(*(__bss_end)); > > > > > > + .bss_end __bss_limit (OVERLAY) : { > > > > > > + KEEP(*(.__bss_end)); > > > > > > } > > > > > > > > > > > > /DISCARD/ : { *(.dynstr*) } > > > > > > diff --git a/board/actux1/u-boot.lds b/board/actux1/u-boot.lds > > > > > > index c76728a..7e5c4d8 100644 > > > > > > --- a/board/actux1/u-boot.lds > > > > > > +++ b/board/actux1/u-boot.lds > > > > > > @@ -74,17 +74,23 @@ SECTIONS > > > > > > > > > > > > _end = .; > > > > > > > > > > > > +/* > > > > > > + * Compiler-generated __bss_start and __bss_end, see > > > > > > arch/arm/lib/bss.c > > > > > > + * __bss_base and __bss_limit are for linker only (overlay > > > > > > ordering) > > > > > > + */ > > > > > > + > > > > > > .bss_start __rel_dyn_start (OVERLAY) : { > > > > > > KEEP(*(.__bss_start)); > > > > > > + HIDDEN(__bss_base = .); > > > > > > } > > > > > > > > > > > > - .bss __bss_start (OVERLAY) : { > > > > > > + .bss __bss_base (OVERLAY) : { > > > > > > *(.bss*) > > > > > > . = ALIGN(4); > > > > > > - __bss_end = .; > > > > > > + HIDDEN(__bss_limit = .); > > > > > > } > > > > > > - .bss_end __bss_end (OVERLAY) : { > > > > > > - KEEP(*(__bss_end)); > > > > > > + .bss_end __bss_limit (OVERLAY) : { > > > > > > + KEEP(*(.__bss_end)); > > > > > > } > > > > > > > > > > > > /DISCARD/ : { *(.dynstr*) } > > > > > > diff --git a/board/actux2/u-boot.lds b/board/actux2/u-boot.lds > > > > > > index 984f70e..ce1b7c9 100644 > > > > > > --- a/board/actux2/u-boot.lds > > > > > > +++ b/board/actux2/u-boot.lds > > > > > > @@ -74,17 +74,23 @@ SECTIONS > > > > > > > > > > > > _end = .; > > > > > > > > > > > > +/* > > > > > > + * Compiler-generated __bss_start and __bss_end, see > > > > > > arch/arm/lib/bss.c > > > > > > + * __bss_base and __bss_limit are for linker only (overlay > > > > > > ordering) > > > > > > + */ > > > > > > + > > > > > > .bss_start __rel_dyn_start (OVERLAY) : { > > > > > > KEEP(*(.__bss_start)); > > > > > > + HIDDEN(__bss_base = .); > > > > > > } > > > > > > > > > > > > - .bss __bss_start (OVERLAY) : { > > > > > > + .bss __bss_base (OVERLAY) : { > > > > > > *(.bss*) > > > > > > . = ALIGN(4); > > > > > > - __bss_end = .; > > > > > > + HIDDEN(__bss_limit = .); > > > > > > } > > > > > > - .bss_end __bss_end (OVERLAY) : { > > > > > > - KEEP(*(__bss_end)); > > > > > > + .bss_end __bss_limit (OVERLAY) : { > > > > > > + KEEP(*(.__bss_end)); > > > > > > } > > > > > > > > > > > > /DISCARD/ : { *(.dynstr*) } > > > > > > diff --git a/board/actux3/u-boot.lds b/board/actux3/u-boot.lds > > > > > > index fc48cf0..3e091dd 100644 > > > > > > --- a/board/actux3/u-boot.lds > > > > > > +++ b/board/actux3/u-boot.lds > > > > > > @@ -74,17 +74,23 @@ SECTIONS > > > > > > > > > > > > _end = .; > > > > > > > > > > > > +/* > > > > > > + * Compiler-generated __bss_start and __bss_end, see > > > > > > arch/arm/lib/bss.c > > > > > > + * __bss_base and __bss_limit are for linker only (overlay > > > > > > ordering) > > > > > > + */ > > > > > > + > > > > > > .bss_start __rel_dyn_start (OVERLAY) : { > > > > > > KEEP(*(.__bss_start)); > > > > > > + HIDDEN(__bss_base = .); > > > > > > } > > > > > > > > > > > > - .bss __bss_start (OVERLAY) : { > > > > > > + .bss __bss_base (OVERLAY) : { > > > > > > *(.bss*) > > > > > > . = ALIGN(4); > > > > > > - __bss_end = .; > > > > > > + HIDDEN(__bss_limit = .); > > > > > > } > > > > > > - .bss_end __bss_end (OVERLAY) : { > > > > > > - KEEP(*(__bss_end)); > > > > > > + .bss_end __bss_limit (OVERLAY) : { > > > > > > + KEEP(*(.__bss_end)); > > > > > > } > > > > > > > > > > > > /DISCARD/ : { *(.dynstr*) } > > > > > > diff --git a/board/dvlhost/u-boot.lds b/board/dvlhost/u-boot.lds > > > > > > index b13d3e1..fe3c21b 100644 > > > > > > --- a/board/dvlhost/u-boot.lds > > > > > > +++ b/board/dvlhost/u-boot.lds > > > > > > @@ -74,17 +74,23 @@ SECTIONS > > > > > > > > > > > > _end = .; > > > > > > > > > > > > +/* > > > > > > + * Compiler-generated __bss_start and __bss_end, see > > > > > > arch/arm/lib/bss.c > > > > > > + * __bss_base and __bss_limit are for linker only (overlay > > > > > > ordering) > > > > > > + */ > > > > > > + > > > > > > .bss_start __rel_dyn_start (OVERLAY) : { > > > > > > KEEP(*(.__bss_start)); > > > > > > + HIDDEN(__bss_base = .); > > > > > > } > > > > > > > > > > > > - .bss __bss_start (OVERLAY) : { > > > > > > + .bss __bss_base (OVERLAY) : { > > > > > > *(.bss*) > > > > > > . = ALIGN(4); > > > > > > - __bss_end = .; > > > > > > + HIDDEN(__bss_limit = .); > > > > > > } > > > > > > - .bss_end __bss_end (OVERLAY) : { > > > > > > - KEEP(*(__bss_end)); > > > > > > + .bss_end __bss_limit (OVERLAY) : { > > > > > > + KEEP(*(.__bss_end)); > > > > > > } > > > > > > > > > > > > /DISCARD/ : { *(.dynstr*) } > > > > > > diff --git a/board/freescale/mx31ads/u-boot.lds > > > > > > b/board/freescale/mx31ads/u-boot.lds > > > > > > index 264c4e8..e6885a5 100644 > > > > > > --- a/board/freescale/mx31ads/u-boot.lds > > > > > > +++ b/board/freescale/mx31ads/u-boot.lds > > > > > > @@ -80,17 +80,23 @@ SECTIONS > > > > > > > > > > > > _end = .; > > > > > > > > > > > > +/* > > > > > > + * Compiler-generated __bss_start and __bss_end, see > > > > > > arch/arm/lib/bss.c > > > > > > + * __bss_base and __bss_limit are for linker only (overlay > > > > > > ordering) > > > > > > + */ > > > > > > + > > > > > > .bss_start __rel_dyn_start (OVERLAY) : { > > > > > > KEEP(*(.__bss_start)); > > > > > > + HIDDEN(__bss_base = .); > > > > > > } > > > > > > > > > > > > - .bss __bss_start (OVERLAY) : { > > > > > > + .bss __bss_base (OVERLAY) : { > > > > > > *(.bss*) > > > > > > . = ALIGN(4); > > > > > > - __bss_end = .; > > > > > > + HIDDEN(__bss_limit = .); > > > > > > } > > > > > > - .bss_end __bss_end (OVERLAY) : { > > > > > > - KEEP(*(__bss_end)); > > > > > > + .bss_end __bss_limit (OVERLAY) : { > > > > > > + KEEP(*(.__bss_end)); > > > > > > } > > > > > > > > > > > > /DISCARD/ : { *(.bss*) } > > > > > > -- > > > > > > 1.7.10.4 > > > > > > > > > > > > > > > > > > > > > > Looks good, but what about the __bss_end in > > > > > ASSERT(__bss_end < (CONFIG_SPL_TEXT_BASE + CONFIG_SPL_MAX_SIZE), "SPL > > > > > image > > > > > too big"); > > > > > ? > > > > > > > > > > Shouldn't it be replaced with __bss_limit, or even better, with > > > > > __image_copy_end > > > > > (why should BSS be taken into account for SPL image size?)? > > > > > > > > I meant __bss_base, not __image_copy_end. > > > > > > Part of SPL can use BSS, once board_init_f() has handed things over to > > > board_init_r(), > > > > I agree with that. > > > > > and this test is meant to ensure that .text+.data+.bss > > > fits in the RAM available to SPL. This ASSERT() compares the upper > > > limit of this RAM to the upper limit of the SPL needs, i.e. __bss_end. > > > > > > IOW, this ASSERT is about how much memory SPL will use when it runs, > > > > This is where there might be an issue with the definition / usage of > > CONFIG_SPL_MAX_SIZE. > > > > I had understood that this is the purpose of this assert, but this usage of > > CONFIG_SPL_MAX_SIZE, while frequent on arm, conflicts with its definition > > in > > README, as well as with some arm and other usages, e.g. in > > include/configs/am335x_evm.h or include/configs/p1_p2_rdb_pc.h.
It's not even that frequent on ARM. I've looked at a few other ARM linker scripts (arm1136, omap), and they don't count bss in CONFIG_SPL_MAX_SIZE. > > The README's definition is also how I understood this config when > > discussing it > > with Scott about my 16/30, which led to the #error test that was added at > > some > > point to this patch. > > Sorry, I'd missed that. Adding Stephen for any comment regarding the > ASSERT() and CONFIG_SPL_MAX_SIZE semantics. > > > According to README, CONFIG_SPL_MAX_SIZE is for text + data + rodata (i.e. > > for > > the size of the binary image file to be programmed on the target device), > > while > > CONFIG_SPL_BSS_MAX_SIZE is dedicated to the BSS. Hence, in order to comply > > with > > this definition, that assert should either use __bss_base/__bss_start, or > > compare against CONFIG_SPL_MAX_SIZE + CONFIG_SPL_BSS_MAX_SIZE, depending on > > whether it's supposed to test the binary image size or the memory > > footprint. > > There could even be asserts testing both. This would anyway be a new patch > > separate from this one. > > It would indeed be a different patch. > > IIUC, this future patch would increase the limit for SPL run-time size, > as the constant against which the ASS tests __bss_end for would > necessarily be greater than it is now. Correct? If so, this future > patch should not break any target, as it would loosen the constraint, > not tighten it. Yes, it would either be the same or relaxed a bit, depending on the chosen option: - Define CONFIG_SPL_BSS_MAX_SIZE and test against CONFIG_SPL_MAX_SIZE + CONFIG_SPL_BSS_MAX_SIZE, the sum remaining the same as or being larger than currently, depending on the new values for CONFIG_SPL_MAX_SIZE and CONFIG_SPL_BSS_MAX_SIZE. - Define a new config meaning text + data + rodata + bss (e.g. CONFIG_SPL_MAX_RAM_SIZE or CONFIG_SPL_MAX_MEM_FOOTPRINT), and just replace CONFIG_SPL_MAX_SIZE with it for the users of arch/arm/cpu/u-boot*.lds, taking care that this was the only meaning those users were giving to CONFIG_SPL_MAX_SIZE. The first option would probably be preferable, using the same value for CONFIG_SPL_MAX_SIZE, and a non-zero value for CONFIG_SPL_BSS_MAX_SIZE. > Tom, would such a patch, if posted today, be acceptable for 2013.04? > > > If you decided not to change that, CONFIG_SPL_MAX_SIZE would have different > > meanings depending on the board, and CONFIG_SPL_PAD_TO could be smaller > > than it > > in some cases, so the #error test in my 16/30 could be removed, but no such > > case > > exists so far, making this 16/30 change not strictly necessary for now. > > IF a patch is posted, it should be done above your series, and take > care of fixing 16/30 as necessary. If this assert is fixed according to the README definition, nothing needs to be changed in 16/30. > Now, pending Tom's approval, the question is: who does this future > patch? > > Benoît, You obviously have most of the necessary inputs, but I might > be more available to prepare a patch now. Your pick -- and in any case, > you earn a second Reported-By: badge. :) I let you handle this, and approved for my RB badge. :) Best regards, Benoît _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot