* [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
@ 2007-12-07 11:16 Wolfgang Denk
2007-12-07 13:28 ` Josh Boyer
2008-01-12 19:34 ` [U-Boot-Users] " Wolfgang Denk
0 siblings, 2 replies; 22+ messages in thread
From: Wolfgang Denk @ 2007-12-07 11:16 UTC (permalink / raw)
To: u-boot
With recent toolchain versions, some boards would not build because
or errors like this one (here for ocotea board when building with
ELDK 4.2):
ppc_4xx-ld: section .bootpg [fffff000 -> fffff23b] overlaps section .bss [fffee900 -> fffff8ab]
For many boards, the .bss section is big enough that it wraps around
at the end of the address space (0xFFFFFFFF), so the problem will not
be visible unless you use a 64 bit tool chain for development. On
some boards however, changes to the code size (due to different
optimizations) we bail out with section overlaps like above.
The fix is to add the NOLOAD attribute to the .bss and .sbss
sections, telling the linker that .bss does not consume any space in
the image.
Signed-off-by: Wolfgang Denk <wd@denx.de>
---
board/BuS/EB+MCF-EV123/u-boot.lds | 2 +-
board/LEOX/elpt860/u-boot.lds | 2 +-
board/MAI/AmigaOneG3SE/u-boot.lds | 2 +-
board/Marvell/db64360/u-boot.lds | 2 +-
board/Marvell/db64460/u-boot.lds | 2 +-
board/RPXClassic/u-boot.lds | 2 +-
board/RPXlite/u-boot.lds | 2 +-
board/RPXlite_dw/u-boot.lds | 2 +-
board/RRvision/u-boot.lds | 2 +-
board/adder/u-boot.lds | 2 +-
board/ads5121/u-boot.lds | 2 +-
board/adsvix/u-boot.lds | 2 +-
board/altera/dk1c20/u-boot.lds | 2 +-
board/altera/dk1s10/u-boot.lds | 2 +-
board/altera/ep1c20/u-boot.lds | 4 ++--
board/altera/ep1s10/u-boot.lds | 4 ++--
board/altera/ep1s40/u-boot.lds | 4 ++--
board/amcc/acadia/u-boot-nand.lds | 2 +-
board/amcc/acadia/u-boot.lds | 2 +-
board/amcc/bamboo/u-boot-nand.lds | 2 +-
board/amcc/bamboo/u-boot.lds | 2 +-
board/amcc/bubinga/u-boot.lds | 2 +-
board/amcc/ebony/u-boot.lds | 2 +-
board/amcc/katmai/u-boot.lds | 2 +-
board/amcc/luan/u-boot.lds | 2 +-
board/amcc/ocotea/u-boot.lds | 2 +-
board/amcc/sequoia/u-boot-nand.lds | 2 +-
board/amcc/sequoia/u-boot.lds | 2 +-
board/amcc/taihu/u-boot.lds | 2 +-
board/amcc/taishan/u-boot.lds | 2 +-
board/amcc/walnut/u-boot.lds | 2 +-
board/amcc/yosemite/u-boot.lds | 2 +-
board/amcc/yucca/u-boot.lds | 2 +-
board/amirix/ap1000/u-boot.lds | 2 +-
board/armadillo/u-boot.lds | 2 +-
board/assabet/u-boot.lds | 2 +-
board/at91rm9200dk/u-boot.lds | 2 +-
board/atmel/atstk1000/u-boot.lds | 2 +-
board/c2mon/u-boot.lds | 2 +-
board/cds/mpc8541cds/u-boot.lds | 2 +-
board/cds/mpc8548cds/u-boot.lds | 2 +-
board/cds/mpc8555cds/u-boot.lds | 2 +-
board/cerf250/u-boot.lds | 2 +-
board/cm4008/u-boot.lds | 2 +-
board/cm41xx/u-boot.lds | 2 +-
board/cm5200/u-boot.lds | 2 +-
board/cmc_pu2/u-boot.lds | 2 +-
board/cobra5272/u-boot.lds | 2 +-
board/cogent/u-boot.lds | 2 +-
board/cradle/u-boot.lds | 2 +-
board/cray/L1/u-boot.lds | 2 +-
board/csb226/u-boot.lds | 2 +-
board/csb272/u-boot.lds | 2 +-
board/csb472/u-boot.lds | 2 +-
board/csb637/u-boot.lds | 2 +-
board/dave/B2/u-boot.lds | 2 +-
board/dave/PPChameleonEVB/u-boot.lds | 2 +-
board/davinci/dv-evm/u-boot.lds | 2 +-
board/davinci/schmoogie/u-boot.lds | 2 +-
board/davinci/sonata/u-boot.lds | 2 +-
board/dbau1x00/u-boot.lds | 4 ++--
board/delta/u-boot.lds | 2 +-
board/dnp1110/u-boot.lds | 2 +-
board/eltec/bab7xx/u-boot.lds | 2 +-
board/eltec/elppc/u-boot.lds | 2 +-
board/eltec/mhpc/u-boot.lds | 2 +-
board/emk/top860/u-boot.lds | 2 +-
board/ep7312/u-boot.lds | 2 +-
board/ep88x/u-boot.lds | 2 +-
board/eric/u-boot.lds | 2 +-
board/esd/adciop/u-boot.lds | 2 +-
board/esd/apc405/u-boot.lds | 2 +-
board/esd/ar405/u-boot.lds | 2 +-
board/esd/ash405/u-boot.lds | 2 +-
board/esd/canbt/u-boot.lds | 2 +-
board/esd/cms700/u-boot.lds | 2 +-
board/esd/cpci2dp/u-boot.lds | 2 +-
board/esd/cpci405/u-boot.lds | 2 +-
board/esd/cpci440/u-boot.lds | 2 +-
board/esd/cpci750/u-boot.lds | 2 +-
board/esd/cpciiser4/u-boot.lds | 2 +-
board/esd/dasa_sim/u-boot.lds | 2 +-
board/esd/dp405/u-boot.lds | 2 +-
board/esd/du405/u-boot.lds | 2 +-
board/esd/hh405/u-boot.lds | 2 +-
board/esd/hub405/u-boot.lds | 2 +-
board/esd/ocrtc/u-boot.lds | 2 +-
board/esd/pci405/u-boot.lds | 2 +-
board/esd/plu405/u-boot.lds | 2 +-
board/esd/pmc405/u-boot.lds | 2 +-
board/esd/tasreg/u-boot.lds | 2 +-
board/esd/voh405/u-boot.lds | 2 +-
board/esd/vom405/u-boot.lds | 2 +-
board/esd/wuh405/u-boot.lds | 2 +-
board/esteem192e/u-boot.lds | 2 +-
board/etx094/u-boot.lds | 2 +-
board/evb4510/u-boot.lds | 2 +-
board/evb64260/u-boot.lds | 2 +-
board/exbitgen/u-boot.lds | 2 +-
board/fads/u-boot.lds | 2 +-
board/flagadm/u-boot.lds | 2 +-
board/freescale/m5235evb/u-boot.lds | 2 +-
board/freescale/m5249evb/u-boot.lds | 2 +-
board/freescale/m5253evbe/u-boot.lds | 2 +-
board/freescale/m5329evb/u-boot.lds | 2 +-
board/freescale/m54455evb/u-boot.lds | 2 +-
board/freescale/mpc8544ds/u-boot.lds | 2 +-
board/freescale/mpc8641hpcn/u-boot.lds | 2 +-
board/g2000/u-boot.lds | 2 +-
board/gcplus/u-boot.lds | 2 +-
board/gen860t/u-boot-flashenv.lds | 2 +-
board/gen860t/u-boot.lds | 2 +-
board/genietv/u-boot.lds | 2 +-
board/gth/u-boot.lds | 2 +-
board/gth2/u-boot.lds | 4 ++--
board/hermes/u-boot.lds | 2 +-
board/hymod/u-boot.lds | 2 +-
board/icu862/u-boot.lds | 2 +-
board/idmr/u-boot.lds | 2 +-
board/impa7/u-boot.lds | 2 +-
board/incaip/u-boot.lds | 4 ++--
board/innokom/u-boot.lds | 2 +-
board/ip860/u-boot.lds | 2 +-
board/ivm/u-boot.lds | 2 +-
board/ixdp425/u-boot.lds | 2 +-
board/jse/u-boot.lds | 2 +-
board/kb9202/u-boot.lds | 2 +-
board/kup/kup4k/u-boot.lds | 2 +-
board/kup/kup4x/u-boot.lds | 2 +-
board/lantec/u-boot.lds | 2 +-
board/lart/u-boot.lds | 2 +-
board/logodl/u-boot.lds | 2 +-
board/lpc2292sodimm/u-boot.lds | 2 +-
board/lpd7a40x/u-boot.lds | 2 +-
board/lubbock/u-boot.lds | 2 +-
board/lwmon/u-boot.lds | 2 +-
board/lwmon5/u-boot.lds | 2 +-
board/m5271evb/u-boot.lds | 2 +-
board/m5272c3/u-boot.lds | 2 +-
board/m5282evb/u-boot.lds | 2 +-
board/mbx8xx/u-boot.lds | 2 +-
board/ml2/u-boot.lds | 2 +-
board/modnet50/u-boot.lds | 2 +-
board/mousse/u-boot.lds | 2 +-
board/mp2usb/u-boot.lds | 2 +-
board/mpc7448hpc2/u-boot.lds | 2 +-
board/mpc8540ads/u-boot.lds | 2 +-
board/mpc8540eval/u-boot.lds | 2 +-
board/mpc8560ads/u-boot.lds | 2 +-
board/mpc8568mds/u-boot.lds | 2 +-
board/mpl/mip405/u-boot.lds | 2 +-
board/mpl/pip405/u-boot.lds | 2 +-
board/mpl/vcma9/u-boot.lds | 2 +-
board/mvs1/u-boot.lds | 2 +-
board/mx1ads/u-boot.lds | 2 +-
board/mx1fs2/u-boot.lds | 2 +-
board/nc650/u-boot.lds | 2 +-
board/netphone/u-boot.lds | 2 +-
board/netstal/hcu4/u-boot.lds | 2 +-
board/netstal/hcu5/u-boot.lds | 2 +-
board/netstar/u-boot.lds | 2 +-
board/netta/u-boot.lds | 2 +-
board/netta2/u-boot.lds | 2 +-
board/netvia/u-boot.lds | 2 +-
board/ns9750dev/u-boot.lds | 2 +-
board/nx823/u-boot.lds | 2 +-
board/omap1510inn/u-boot.lds | 2 +-
board/omap1610inn/u-boot.lds | 2 +-
board/omap2420h4/u-boot.lds | 2 +-
board/omap5912osk/u-boot.lds | 2 +-
board/omap730p2/u-boot.lds | 2 +-
board/pb1x00/u-boot.lds | 4 ++--
board/pcippc2/u-boot.lds | 2 +-
board/pcs440ep/u-boot.lds | 2 +-
board/pleb2/u-boot.lds | 2 +-
board/pm854/u-boot.lds | 2 +-
board/pm856/u-boot.lds | 2 +-
board/ppmc7xx/u-boot.lds | 2 +-
board/prodrive/alpr/u-boot.lds | 2 +-
board/prodrive/p3mx/u-boot.lds | 2 +-
board/prodrive/p3p440/u-boot.lds | 2 +-
board/prodrive/pdnb3/u-boot.lds | 2 +-
board/psyent/pci5441/u-boot.lds | 4 ++--
board/psyent/pk1c20/u-boot.lds | 4 ++--
board/purple/u-boot.lds | 4 ++--
board/pxa255_idp/u-boot.lds | 2 +-
board/quantum/u-boot.lds | 2 +-
board/r360mpi/u-boot.lds | 2 +-
board/r5200/u-boot.lds | 2 +-
board/rbc823/u-boot.lds | 2 +-
board/rmu/u-boot.lds | 2 +-
board/rsdproto/u-boot.lds | 2 +-
board/sandburst/karef/u-boot.lds | 2 +-
board/sandburst/metrobox/u-boot.lds | 2 +-
board/sbc2410x/u-boot.lds | 2 +-
board/sbc405/u-boot.lds | 2 +-
board/sbc8560/u-boot.lds | 2 +-
board/sbc8641d/u-boot.lds | 2 +-
board/sc3/u-boot.lds | 2 +-
board/sc520_cdp/u-boot.lds | 2 +-
board/sc520_spunk/u-boot.lds | 2 +-
board/scb9328/u-boot.lds | 2 +-
board/shannon/u-boot.lds | 2 +-
board/siemens/CCM/u-boot.lds | 2 +-
board/siemens/IAD210/u-boot.lds | 2 +-
board/siemens/SMN42/u-boot.lds | 2 +-
board/siemens/pcu_e/u-boot.lds | 2 +-
board/sixnet/u-boot.lds | 2 +-
board/smdk2400/u-boot.lds | 2 +-
board/smdk2410/u-boot.lds | 2 +-
board/snmc/qs850/u-boot.lds | 2 +-
board/snmc/qs860t/u-boot.lds | 2 +-
board/spc1920/u-boot.lds | 2 +-
board/spd8xx/u-boot.lds | 2 +-
board/ssv/adnpesc1/u-boot.lds | 2 +-
board/stxgp3/u-boot.lds | 2 +-
board/stxssa/u-boot.lds | 2 +-
board/stxxtc/u-boot.lds | 2 +-
board/svm_sc8xx/u-boot.lds | 2 +-
board/sx1/u-boot.lds | 2 +-
board/tb0229/u-boot.lds | 4 ++--
board/tqm85xx/u-boot.lds | 2 +-
board/tqm8xx/u-boot.lds | 2 +-
board/trab/u-boot.lds | 2 +-
board/trizepsiv/u-boot.lds | 2 +-
board/uc100/u-boot.lds | 2 +-
board/v37/u-boot.lds | 2 +-
board/versatile/u-boot.lds | 2 +-
board/voiceblue/u-boot.lds | 2 +-
board/w7o/u-boot.lds | 2 +-
board/wepep250/u-boot.lds | 2 +-
board/westel/amx860/u-boot.lds | 2 +-
board/xaeniax/u-boot.lds | 2 +-
board/xilinx/ml300/u-boot.lds | 2 +-
board/xm250/u-boot.lds | 2 +-
board/xpedite1k/u-boot.lds | 2 +-
board/xsengine/u-boot.lds | 2 +-
board/zeus/u-boot.lds | 2 +-
board/zylonite/u-boot.lds | 2 +-
cpu/mpc5xx/u-boot.lds | 2 +-
cpu/mpc5xxx/u-boot-customlayout.lds | 2 +-
cpu/mpc5xxx/u-boot.lds | 2 +-
cpu/mpc8220/u-boot.lds | 2 +-
cpu/mpc824x/u-boot.lds | 2 +-
cpu/mpc8260/u-boot.lds | 2 +-
cpu/mpc83xx/u-boot.lds | 2 +-
nand_spl/board/amcc/acadia/u-boot.lds | 2 +-
nand_spl/board/amcc/bamboo/u-boot.lds | 2 +-
nand_spl/board/amcc/sequoia/u-boot.lds | 2 +-
249 files changed, 260 insertions(+), 260 deletions(-)
Patch exceeds mailing list's message size limit.
Please see ftp://ftp.denx.de/pub/tmp/Fix-linker-scripts-BSS-NOLOAD.patch
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2007-12-07 11:16 [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections Wolfgang Denk
@ 2007-12-07 13:28 ` Josh Boyer
2007-12-11 22:50 ` brino
2008-01-12 19:34 ` [U-Boot-Users] " Wolfgang Denk
1 sibling, 1 reply; 22+ messages in thread
From: Josh Boyer @ 2007-12-07 13:28 UTC (permalink / raw)
To: u-boot
On Fri, 7 Dec 2007 12:16:54 +0100
Wolfgang Denk <wd@denx.de> wrote:
> With recent toolchain versions, some boards would not build because
> or errors like this one (here for ocotea board when building with
> ELDK 4.2):
> ppc_4xx-ld: section .bootpg [fffff000 -> fffff23b] overlaps section .bss [fffee900 -> fffff8ab]
>
> For many boards, the .bss section is big enough that it wraps around
> at the end of the address space (0xFFFFFFFF), so the problem will not
> be visible unless you use a 64 bit tool chain for development. On
> some boards however, changes to the code size (due to different
> optimizations) we bail out with section overlaps like above.
>
> The fix is to add the NOLOAD attribute to the .bss and .sbss
> sections, telling the linker that .bss does not consume any space in
> the image.
YAY! I've been having to work around this for a while now. Looking
forward to trying it out.
josh
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2007-12-07 13:28 ` Josh Boyer
@ 2007-12-11 22:50 ` brino
2007-12-12 11:17 ` Clemens Koller
0 siblings, 1 reply; 22+ messages in thread
From: brino @ 2007-12-11 22:50 UTC (permalink / raw)
To: u-boot
Hi All,
This fix doesn't work with binutils-2.18. I'm building u-boot for the amcc
yosemite board using cygwin and cross binutils-2.18/gcc-4.2.2 for a
powerpc-eabi target. The linker complains that "section .text can't be
allocated in segment 0." The .bss section is by default a NOLOAD section
with binutils-2.18 meaning it occupies no space in the file. However, the
.bss section is an ALLOC section meaning it does occupy space in target
memory. The linker runs an error check to make sure all sections will
fit within the file and all sections will fit within target memory. All
sections
do fit within the file, however the sections do not fit within target memory
because of the wrap around end of memory.
We could definitely drop the TEXT_BASE address lower which would fix
the problem, but isn't ideal since the image would take up more flash for
no reason. We could link with TEXT_BASE=0 and then burn it to flash at
address 0xFFF80000 (this is where the current TEXT_BASE is for the
yosemite board). Whats the reason it's linked at 0xFFF80000 anyway?
Is there an elf loader which burns it into flash? There's also the 'AT'
attribute in the linker script which may help, however, I don't quite
understand the use of it yet. Any suggestions on how to approach this?
Thanks,
Brian
Josh Boyer-3 wrote:
>
> On Fri, 7 Dec 2007 12:16:54 +0100
> Wolfgang Denk <wd@denx.de> wrote:
>
>> With recent toolchain versions, some boards would not build because
>> or errors like this one (here for ocotea board when building with
>> ELDK 4.2):
>> ppc_4xx-ld: section .bootpg [fffff000 -> fffff23b] overlaps section .bss
>> [fffee900 -> fffff8ab]
>>
>> For many boards, the .bss section is big enough that it wraps around
>> at the end of the address space (0xFFFFFFFF), so the problem will not
>> be visible unless you use a 64 bit tool chain for development. On
>> some boards however, changes to the code size (due to different
>> optimizations) we bail out with section overlaps like above.
>>
>> The fix is to add the NOLOAD attribute to the .bss and .sbss
>> sections, telling the linker that .bss does not consume any space in
>> the image.
>
> YAY! I've been having to work around this for a while now. Looking
> forward to trying it out.
>
> josh
>
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>
>
--
View this message in context: http://www.nabble.com/-PATCH--Fix-linker-scripts%3A-add-NOLOAD-atribute-to-.bss-.sbss-sections-tp14210775p14285357.html
Sent from the Uboot - Users mailing list archive at Nabble.com.
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2007-12-11 22:50 ` brino
@ 2007-12-12 11:17 ` Clemens Koller
2007-12-12 11:32 ` [U-Boot-Users] fixed: " Clemens Koller
0 siblings, 1 reply; 22+ messages in thread
From: Clemens Koller @ 2007-12-12 11:17 UTC (permalink / raw)
To: u-boot
brino schrieb:
> Hi All,
>
> This fix doesn't work with binutils-2.18. I'm building u-boot for the amcc
> yosemite board using cygwin and cross binutils-2.18/gcc-4.2.2 for a
> powerpc-eabi target.
Yes, binutils-2.18 have this broken. binutils-2.17 work fine.
> The linker complains that "section .text can't be
> allocated in segment 0." The .bss section is by default a NOLOAD section
> with binutils-2.18 meaning it occupies no space in the file. However, the
> .bss section is an ALLOC section meaning it does occupy space in target
> memory. The linker runs an error check to make sure all sections will
> fit within the file and all sections will fit within target memory. All
> sections
> do fit within the file, however the sections do not fit within target memory
> because of the wrap around end of memory.
>
> We could definitely drop the TEXT_BASE address lower which would fix
> the problem, but isn't ideal since the image would take up more flash for
> no reason. We could link with TEXT_BASE=0 and then burn it to flash at
> address 0xFFF80000 (this is where the current TEXT_BASE is for the
> yosemite board). Whats the reason it's linked at 0xFFF80000 anyway?
> Is there an elf loader which burns it into flash? There's also the 'AT'
> attribute in the linker script which may help, however, I don't quite
> understand the use of it yet. Any suggestions on how to approach this?
I am about to verify the latest binutils-snapshot. There have been
the following patch included:
http://sourceware.org/ml/binutils/2007-11/msg00235.html
which should fix that issue.
Please be patient... I'll give you an update ASAP.
Regards,
Clemens Koller
__________________________________
R&D Imaging Devices
Anagramm GmbH
Rupert-Mayer-Stra?e 45/1
Linhof Werksgel?nde
D-81379 M?nchen
Tel.089-741518-50
Fax 089-741518-19
http://www.anagramm-technology.com
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] fixed: Re: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2007-12-12 11:17 ` Clemens Koller
@ 2007-12-12 11:32 ` Clemens Koller
0 siblings, 0 replies; 22+ messages in thread
From: Clemens Koller @ 2007-12-12 11:32 UTC (permalink / raw)
To: u-boot
[CCed to current thread at binutils list: Re: binutils-2.18 and U-Boot]
Clemens Koller schrieb:
> brino schrieb:
> > Hi All,
> >
> > This fix doesn't work with binutils-2.18. I'm building u-boot for the amcc
> > yosemite board using cygwin and cross binutils-2.18/gcc-4.2.2 for a
> > powerpc-eabi target.
>
> Yes, binutils-2.18 have this broken. binutils-2.17 work fine.
In the latest binutils-snapshot (at least):
$ ld -v
GNU ld (GNU Binutils) 2.18.50.20071212
this problem was fixed by:
http://sourceware.org/ml/binutils/2007-11/msg00235.html
U-Boot
commit 41be969f4957115ed7b1fe8b890bfaee99d7a7a2
Author: Wolfgang Denk <wd@denx.de>
Date: Thu Dec 6 10:21:19 2007 +0100
Release v1.3.1
compiled a $ make TQM8540_config target with gcc-4.2.2 within
an native mpc8540 environment.
I cannot run-test now, but I will close binutils bug 5205 now:
http://www.sourceware.org/bugzilla/show_bug.cgi?id=5205
Thanks for the detailed report to Brian and for the fix to Nathan. :-)
Regards,
--
Clemens Koller
__________________________________
R&D Imaging Devices
Anagramm GmbH
Rupert-Mayer-Stra?e 45/1
Linhof Werksgel?nde
D-81379 M?nchen
Tel.089-741518-50
Fax 089-741518-19
http://www.anagramm-technology.com
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2007-12-07 11:16 [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections Wolfgang Denk
2007-12-07 13:28 ` Josh Boyer
@ 2008-01-12 19:34 ` Wolfgang Denk
2008-01-13 13:59 ` Stefan Roese
1 sibling, 1 reply; 22+ messages in thread
From: Wolfgang Denk @ 2008-01-12 19:34 UTC (permalink / raw)
To: u-boot
In message <1197026214-31034-1-git-send-email-wd@denx.de> you wrote:
> With recent toolchain versions, some boards would not build because
> or errors like this one (here for ocotea board when building with
> ELDK 4.2):
> ppc_4xx-ld: section .bootpg [fffff000 -> fffff23b] overlaps section .bss [fffee900 -> fffff8ab]
>
> For many boards, the .bss section is big enough that it wraps around
> at the end of the address space (0xFFFFFFFF), so the problem will not
> be visible unless you use a 64 bit tool chain for development. On
> some boards however, changes to the code size (due to different
> optimizations) we bail out with section overlaps like above.
>
> The fix is to add the NOLOAD attribute to the .bss and .sbss
> sections, telling the linker that .bss does not consume any space in
> the image.
>
> Signed-off-by: Wolfgang Denk <wd@denx.de>
Applied, after re-rworking it for the boards changed, renamed or
added meanwhile.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Your own mileage may vary.
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-01-12 19:34 ` [U-Boot-Users] " Wolfgang Denk
@ 2008-01-13 13:59 ` Stefan Roese
2008-02-03 23:32 ` [U-Boot-Users] [PPC] PLEASE READ - was: " Wolfgang Denk
0 siblings, 1 reply; 22+ messages in thread
From: Stefan Roese @ 2008-01-13 13:59 UTC (permalink / raw)
To: u-boot
Hi Wolfgang,
On Saturday 12 January 2008, Wolfgang Denk wrote:
> In message <1197026214-31034-1-git-send-email-wd@denx.de> you wrote:
> > With recent toolchain versions, some boards would not build because
> > or errors like this one (here for ocotea board when building with
> > ELDK 4.2):
> > ppc_4xx-ld: section .bootpg [fffff000 -> fffff23b] overlaps section .bss
> > [fffee900 -> fffff8ab]
> >
> > For many boards, the .bss section is big enough that it wraps around
> > at the end of the address space (0xFFFFFFFF), so the problem will not
> > be visible unless you use a 64 bit tool chain for development. On
> > some boards however, changes to the code size (due to different
> > optimizations) we bail out with section overlaps like above.
> >
> > The fix is to add the NOLOAD attribute to the .bss and .sbss
> > sections, telling the linker that .bss does not consume any space in
> > the image.
> >
> > Signed-off-by: Wolfgang Denk <wd@denx.de>
>
> Applied, after re-rworking it for the boards changed, renamed or
> added meanwhile.
Thanks. This fixes overlapping problems with bss as seen on Ocotea with
ELDK 4.2. But unfortunately I still have other overlapping problems for
example on Katmai with ELDK 4.2:
[stefan at ubuntu u-boot (master)]$ ./MAKEALL katmai
Configuring for katmai board...
44x_spd_ddr2.c: In function 'initdram':
44x_spd_ddr2.c:392: warning: 'selected_cas' may be used uninitialized in this function
ppc_4xx-ld: section .bootpg [fffff000 -> fffff377] overlaps section .data.rel.local [ffffeba8 -> fffff3f7]
ppc_4xx-ld: u-boot: section .bootpg lma 0xfffff000 overlaps previous sections
ppc_4xx-ld: u-boot: section .data.rel.ro lma 0xfffff3f8 overlaps previous sections
ppc_4xx-ld: u-boot: section .u_boot_cmd lma 0xfffff408 overlaps previous sections
make: *** [u-boot] Error 1
These error are not seen with ELDK 4.1 by the way. Any ideas what might
be causing this and/or how to solve it?
Thanks.
Best regards,
Stefan
=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de
=====================================================================
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-01-13 13:59 ` Stefan Roese
@ 2008-02-03 23:32 ` Wolfgang Denk
2008-02-04 10:37 ` Stefan Roese
` (2 more replies)
0 siblings, 3 replies; 22+ messages in thread
From: Wolfgang Denk @ 2008-02-03 23:32 UTC (permalink / raw)
To: u-boot
Dear Stefan,
in message <200801131459.19164.sr@denx.de> you wrote:
>
> Thanks. This fixes overlapping problems with bss as seen on Ocotea with
> ELDK 4.2. But unfortunately I still have other overlapping problems for
> example on Katmai with ELDK 4.2:
...
> ppc_4xx-ld: u-boot: section .bootpg lma 0xfffff000 overlaps previous sections
> ppc_4xx-ld: u-boot: section .data.rel.ro lma 0xfffff3f8 overlaps previous sections
> ppc_4xx-ld: u-boot: section .u_boot_cmd lma 0xfffff408 overlaps previous sections
> make: *** [u-boot] Error 1
This problem comes from the fact that the code has become larger when
using GCC 4.2.x; this is somewhat a surprise as we all expect more
recent versions of the compiler to provide better optimization.
Please see this thread for discussion of the problem:
http://gcc.gnu.org/ml/gcc/2008-01/msg00228.html
Basicly, it comes down to this explanation:
| GCC does not use the load and store multiple instructions because the source
| file declares r29 a global variable:
|
| register volatile gd_t *gd asm ("r29");
|
| The bug fix mentioned above inhibits GCC from using lmw/stmw if global
| registers are present in the contiguous register sequence because GCC
| incorrectly would overwrite the register. If the register variable declaration
| is removed, GCC uses the lmw/stmw instructions. r29 is a bad choice for a
| global register variable.
So far, it is not clear to me what a better choice for a global
register variable could be (i. e. which register we can chose for our
purpose without causing the same or other problems.
A possible approach to this problem is to avoid using a global
register variable and use a plain global variable instead. The
necessary code for this is already there (just commented out); when I
implemented this initially, I decided to use a global register
variable because it gave slightly smaller code.
Here is an overview of the effect (test build of current top of tree
for the "katmai" (PPC440SPe) board):
ELDK Version Register-Var. Globale Var.
text data bss dec text data bss dec
4.0 243292 13700 322340 579332 244160 13808 322340 580308
4.1 243292 13700 322340 579332 244160 13808 322340 580308
4.2 section ... overlaps previous 245496 13188 322340 581024
As you can see, the difference in code size is less than 1 KiB.
My suggestion is to change the code to use a plain global variable,
however I need feedback if we can / want to do that as it effects
*ALL* PowerPC boards.
Please comment.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Accident: A condition in which presence of mind is good, but absence
of body is better.
^ permalink raw reply [flat|nested] 22+ messages in thread* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-03 23:32 ` [U-Boot-Users] [PPC] PLEASE READ - was: " Wolfgang Denk
@ 2008-02-04 10:37 ` Stefan Roese
2008-02-04 16:56 ` Scott Wood
2008-02-04 17:40 ` Timur Tabi
2 siblings, 0 replies; 22+ messages in thread
From: Stefan Roese @ 2008-02-04 10:37 UTC (permalink / raw)
To: u-boot
Hi Wolfgang,
On Monday 04 February 2008, Wolfgang Denk wrote:
> A possible approach to this problem is to avoid using a global
> register variable and use a plain global variable instead. The
> necessary code for this is already there (just commented out); when I
> implemented this initially, I decided to use a global register
> variable because it gave slightly smaller code.
>
> Here is an overview of the effect (test build of current top of tree
> for the "katmai" (PPC440SPe) board):
>
> ELDK Version Register-Var. Globale Var.
> text data bss dec text data bss dec
> 4.0 243292 13700 322340 579332 244160 13808 322340 580308
> 4.1 243292 13700 322340 579332 244160 13808 322340 580308
> 4.2 section ... overlaps previous 245496 13188 322340 581024
>
> As you can see, the difference in code size is less than 1 KiB.
Nice.
> My suggestion is to change the code to use a plain global variable,
> however I need feedback if we can / want to do that as it effects
> *ALL* PowerPC boards.
Acked-by for this change from me. I tested successfully on AMCC Katmai, which
now fits again in the 256k with GCC 4.2.2.
Thanks.
Best regards,
Stefan
=====================================================================
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de
=====================================================================
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-03 23:32 ` [U-Boot-Users] [PPC] PLEASE READ - was: " Wolfgang Denk
2008-02-04 10:37 ` Stefan Roese
@ 2008-02-04 16:56 ` Scott Wood
2008-02-04 19:14 ` Wolfgang Denk
2008-02-04 17:40 ` Timur Tabi
2 siblings, 1 reply; 22+ messages in thread
From: Scott Wood @ 2008-02-04 16:56 UTC (permalink / raw)
To: u-boot
On Mon, Feb 04, 2008 at 12:32:36AM +0100, Wolfgang Denk wrote:
> So far, it is not clear to me what a better choice for a global
> register variable could be (i. e. which register we can chose for our
> purpose without causing the same or other problems.
r2 is generally used for this purpose.
-Scott
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-04 16:56 ` Scott Wood
@ 2008-02-04 19:14 ` Wolfgang Denk
2008-02-04 19:17 ` Scott Wood
2008-02-06 9:59 ` Joakim Tjernlund
0 siblings, 2 replies; 22+ messages in thread
From: Wolfgang Denk @ 2008-02-04 19:14 UTC (permalink / raw)
To: u-boot
In message <20080204165640.GC19264@ld0162-tx32.am.freescale.net> you wrote:
> On Mon, Feb 04, 2008 at 12:32:36AM +0100, Wolfgang Denk wrote:
> > So far, it is not clear to me what a better choice for a global
> > register variable could be (i. e. which register we can chose for our
> > purpose without causing the same or other problems.
>
> r2 is generally used for this purpose.
Hm... R2 is documented to be the TOC pointer?
It seems we could use R15, but I hesitate a bit...
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The flow chart is a most thoroughly oversold piece of program docu-
mentation. -- Frederick Brooks, "The Mythical Man Month"
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-04 19:14 ` Wolfgang Denk
@ 2008-02-04 19:17 ` Scott Wood
2008-02-14 22:19 ` Wolfgang Denk
2008-02-06 9:59 ` Joakim Tjernlund
1 sibling, 1 reply; 22+ messages in thread
From: Scott Wood @ 2008-02-04 19:17 UTC (permalink / raw)
To: u-boot
Wolfgang Denk wrote:
> In message <20080204165640.GC19264@ld0162-tx32.am.freescale.net> you wrote:
>> On Mon, Feb 04, 2008 at 12:32:36AM +0100, Wolfgang Denk wrote:
>>> So far, it is not clear to me what a better choice for a global
>>> register variable could be (i. e. which register we can chose for our
>>> purpose without causing the same or other problems.
>> r2 is generally used for this purpose.
>
> Hm... R2 is documented to be the TOC pointer?
The ABI document says, "Register r2 is reserved for system use and
should not be changed by application code."
Linux uses it for the "current" pointer.
-Scott
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-04 19:17 ` Scott Wood
@ 2008-02-14 22:19 ` Wolfgang Denk
2008-02-15 18:18 ` Joakim Tjernlund
0 siblings, 1 reply; 22+ messages in thread
From: Wolfgang Denk @ 2008-02-14 22:19 UTC (permalink / raw)
To: u-boot
In message <47A764BC.3000303@freescale.com> you wrote:
>
> > Hm... R2 is documented to be the TOC pointer?
>
> The ABI document says, "Register r2 is reserved for system use and
> should not be changed by application code."
OK, tried this, and seems to work. Well, let's throw it out and see
what else it breaks ;-)
Patch posted - my own tests look good, so I will apply it ;-)
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The IQ of the group is the lowest IQ of a member of the group divided
by the number of people in the group.
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-14 22:19 ` Wolfgang Denk
@ 2008-02-15 18:18 ` Joakim Tjernlund
0 siblings, 0 replies; 22+ messages in thread
From: Joakim Tjernlund @ 2008-02-15 18:18 UTC (permalink / raw)
To: u-boot
> -----Original Message-----
> From: u-boot-users-bounces at lists.sourceforge.net [mailto:u-boot-users-bounces at lists.sourceforge.net]
> On Behalf Of Wolfgang Denk
> Sent: den 14 februari 2008 23:19
> To: Scott Wood
> Cc: u-boot-users at lists.sourceforge.net; Stefan Roese
> Subject: Re: [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute
> to .bss/.sbss sections
>
> In message <47A764BC.3000303@freescale.com> you wrote:
> >
> > > Hm... R2 is documented to be the TOC pointer?
> >
> > The ABI document says, "Register r2 is reserved for system use and
> > should not be changed by application code."
>
> OK, tried this, and seems to work. Well, let's throw it out and see
> what else it breaks ;-)
>
> Patch posted - my own tests look good, so I will apply it ;-)
Works here too, limited testing though
Jocke
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-04 19:14 ` Wolfgang Denk
2008-02-04 19:17 ` Scott Wood
@ 2008-02-06 9:59 ` Joakim Tjernlund
2008-02-06 22:11 ` Wolfgang Denk
1 sibling, 1 reply; 22+ messages in thread
From: Joakim Tjernlund @ 2008-02-06 9:59 UTC (permalink / raw)
To: u-boot
On Mon, 2008-02-04 at 20:14 +0100, Wolfgang Denk wrote:
> In message <20080204165640.GC19264@ld0162-tx32.am.freescale.net> you wrote:
> > On Mon, Feb 04, 2008 at 12:32:36AM +0100, Wolfgang Denk wrote:
> > > So far, it is not clear to me what a better choice for a global
> > > register variable could be (i. e. which register we can chose for our
> > > purpose without causing the same or other problems.
> >
> > r2 is generally used for this purpose.
>
> Hm... R2 is documented to be the TOC pointer?
>
> It seems we could use R15, but I hesitate a bit...
I think the register approach is needed if we ever want to
make u-boot fully relocateable.
There are a few global data accesses that needs to be fixed
before that can happen though. There should not be any global data
accesses before relocate_code has done its thing. One of the
first things that happens in board_init_f is:
for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
if ((*init_fnc_ptr) () != 0) {
hang ();
}
}
init_sequence is a global variable.
Is this table really needed? Why not move it inside board_init_f and
save some bytes?
The next is access is env_get_char, this probably needs to move into GD.
I figured global data accesses wasn't allowed(other than GD) at all
before relocate_code()?
Jocke
^ permalink raw reply [flat|nested] 22+ messages in thread* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-06 9:59 ` Joakim Tjernlund
@ 2008-02-06 22:11 ` Wolfgang Denk
2008-02-07 0:20 ` Joakim Tjernlund
0 siblings, 1 reply; 22+ messages in thread
From: Wolfgang Denk @ 2008-02-06 22:11 UTC (permalink / raw)
To: u-boot
In message <1202291955.25864.43.camel@gentoo-jocke.transmode.se> you wrote:
>
> I think the register approach is needed if we ever want to
> make u-boot fully relocateable.
Good point.
> There are a few global data accesses that needs to be fixed
> before that can happen though. There should not be any global data
> accesses before relocate_code has done its thing. One of the
> first things that happens in board_init_f is:
> for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
> if ((*init_fnc_ptr) () != 0) {
> hang ();
> }
> }
> init_sequence is a global variable.
>
> Is this table really needed? Why not move it inside board_init_f and
> save some bytes?
The original idea of the table was that a user could provide (in his
board config file) a private version to allow for easy, #ifdef free
board specific initialization sequences.
Unfortunately I never found the time or resources to complete this.
> The next is access is env_get_char, this probably needs to move into GD.
>
> I figured global data accesses wasn't allowed(other than GD) at all
> before relocate_code()?
They are not exactly forbidden, you just have to know exactly what you
can expect - i. e., usually they just don't make much sense ;-)
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"I refuse to have a battle of wits with an unarmed person."
^ permalink raw reply [flat|nested] 22+ messages in thread* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-06 22:11 ` Wolfgang Denk
@ 2008-02-07 0:20 ` Joakim Tjernlund
2008-02-07 16:13 ` Wolfgang Denk
0 siblings, 1 reply; 22+ messages in thread
From: Joakim Tjernlund @ 2008-02-07 0:20 UTC (permalink / raw)
To: u-boot
> -----Original Message-----
> From: wd at denx.de [mailto:wd at denx.de]
> Sent: den 6 februari 2008 23:11
> To: joakim.tjernlund at transmode.se
> Cc: Scott Wood; u-boot-users at lists.sourceforge.net; Stefan Roese
> Subject: Re: [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute
> to .bss/.sbss sections
>
> In message <1202291955.25864.43.camel@gentoo-jocke.transmode.se> you wrote:
> >
> > I think the register approach is needed if we ever want to
> > make u-boot fully relocateable.
>
> Good point.
>
> > There are a few global data accesses that needs to be fixed
> > before that can happen though. There should not be any global data
> > accesses before relocate_code has done its thing. One of the
> > first things that happens in board_init_f is:
> > for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
> > if ((*init_fnc_ptr) () != 0) {
> > hang ();
> > }
> > }
> > init_sequence is a global variable.
> >
> > Is this table really needed? Why not move it inside board_init_f and
> > save some bytes?
>
> The original idea of the table was that a user could provide (in his
> board config file) a private version to allow for easy, #ifdef free
> board specific initialization sequences.
>
> Unfortunately I never found the time or resources to complete this.
I see, there are a lot of #ifdef in there that can be made more generic
to cut down on the #ifdef's to a minimum. I read between the lines that you
would not object too much if the table was removed?
>
>
> > The next is access is env_get_char, this probably needs to move into GD.
> >
> > I figured global data accesses wasn't allowed(other than GD) at all
> > before relocate_code()?
>
> They are not exactly forbidden, you just have to know exactly what you
> can expect - i. e., usually they just don't make much sense ;-)
Yeah, sadly I just noticed that constant strings are referenced via the
GOT so you can't print those for PPC if you want to make it relocateable.
Any idea how to avoid GOT references for constant strings?
Jocke
>
> Best regards,
>
> Wolfgang Denk
^ permalink raw reply [flat|nested] 22+ messages in thread* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-07 0:20 ` Joakim Tjernlund
@ 2008-02-07 16:13 ` Wolfgang Denk
0 siblings, 0 replies; 22+ messages in thread
From: Wolfgang Denk @ 2008-02-07 16:13 UTC (permalink / raw)
To: u-boot
Dear Joakim,
in message <455f01c8691f$423a7890$c6af69b0$@Tjernlund@transmode.se> you wrote:
>
> > The original idea of the table was that a user could provide (in his
> > board config file) a private version to allow for easy, #ifdef free
> > board specific initialization sequences.
> >
> > Unfortunately I never found the time or resources to complete this.
>
> I see, there are a lot of #ifdef in there that can be made more generic
> to cut down on the #ifdef's to a minimum. I read between the lines that you
> would not object too much if the table was removed?
Only if the resulting code does not grow and is readable...
Since nobody else picked up the idea over all the years it seems it's
not really needed.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
There are two ways of constructing a software design. One way is to
make it so simple that there are obviously no deficiencies and the
other is to make it so complicated that there are no obvious defi-
ciencies. - Charles Anthony Richard Hoare
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-03 23:32 ` [U-Boot-Users] [PPC] PLEASE READ - was: " Wolfgang Denk
2008-02-04 10:37 ` Stefan Roese
2008-02-04 16:56 ` Scott Wood
@ 2008-02-04 17:40 ` Timur Tabi
2008-02-04 19:16 ` Wolfgang Denk
2 siblings, 1 reply; 22+ messages in thread
From: Timur Tabi @ 2008-02-04 17:40 UTC (permalink / raw)
To: u-boot
Wolfgang Denk wrote:
> A possible approach to this problem is to avoid using a global
> register variable and use a plain global variable instead.
Sounds like a good idea to me. If the code works, then this would simplify
things a great deal. The code that reads and writes the gd_t isn't
time-critical anyway.
--
Timur Tabi
Linux kernel developer at Freescale
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-04 17:40 ` Timur Tabi
@ 2008-02-04 19:16 ` Wolfgang Denk
2008-02-04 19:24 ` Timur Tabi
0 siblings, 1 reply; 22+ messages in thread
From: Wolfgang Denk @ 2008-02-04 19:16 UTC (permalink / raw)
To: u-boot
In message <47A74E10.5000106@freescale.com> you wrote:
>
> > A possible approach to this problem is to avoid using a global
> > register variable and use a plain global variable instead.
>
> Sounds like a good idea to me. If the code works, then this would simplify
> things a great deal. The code that reads and writes the gd_t isn't
> time-critical anyway.
Except for the declaration of the variable itself, *nothing* changes.
What do you mean would become simpler?
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
It is surely a great calamity for a human being to have no ob-
sessions. - Robert Bly
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-04 19:16 ` Wolfgang Denk
@ 2008-02-04 19:24 ` Timur Tabi
2008-02-04 20:36 ` Wolfgang Denk
0 siblings, 1 reply; 22+ messages in thread
From: Timur Tabi @ 2008-02-04 19:24 UTC (permalink / raw)
To: u-boot
Wolfgang Denk wrote:
> Except for the declaration of the variable itself, *nothing* changes.
> What do you mean would become simpler?
A normal global variable is simpler than one that's tied to a specific register,
wouldn't you say? I wasn't trying to be that insightful.
--
Timur Tabi
Linux kernel developer at Freescale
^ permalink raw reply [flat|nested] 22+ messages in thread
* [U-Boot-Users] [PPC] PLEASE READ - was: [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections
2008-02-04 19:24 ` Timur Tabi
@ 2008-02-04 20:36 ` Wolfgang Denk
0 siblings, 0 replies; 22+ messages in thread
From: Wolfgang Denk @ 2008-02-04 20:36 UTC (permalink / raw)
To: u-boot
In message <47A76677.6080308@freescale.com> you wrote:
>
> > Except for the declaration of the variable itself, *nothing* changes.
> > What do you mean would become simpler?
>
> A normal global variable is simpler than one that's tied to a specific register,
> wouldn't you say? I wasn't trying to be that insightful.
No, I wouldn't say that. To me a pointer that can live all the time in
a register is simpler than one that lives somewhere in a memory
location and has to be loaded for use - you can see this from the code
size as well.
Also, it's pretty convenient for debugging, for example when you need
to figure out where U-Boot was relocated to in RAM - just add the
offset in struct global_data and you have the relocation offset, for
example.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
It is impractical for the standard to attempt to constrain the
behavior of code that does not obey the constraints of the standard.
- Doug Gwyn
^ permalink raw reply [flat|nested] 22+ messages in thread
end of thread, other threads:[~2008-02-15 18:18 UTC | newest]
Thread overview: 22+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2007-12-07 11:16 [U-Boot-Users] [PATCH] Fix linker scripts: add NOLOAD atribute to .bss/.sbss sections Wolfgang Denk
2007-12-07 13:28 ` Josh Boyer
2007-12-11 22:50 ` brino
2007-12-12 11:17 ` Clemens Koller
2007-12-12 11:32 ` [U-Boot-Users] fixed: " Clemens Koller
2008-01-12 19:34 ` [U-Boot-Users] " Wolfgang Denk
2008-01-13 13:59 ` Stefan Roese
2008-02-03 23:32 ` [U-Boot-Users] [PPC] PLEASE READ - was: " Wolfgang Denk
2008-02-04 10:37 ` Stefan Roese
2008-02-04 16:56 ` Scott Wood
2008-02-04 19:14 ` Wolfgang Denk
2008-02-04 19:17 ` Scott Wood
2008-02-14 22:19 ` Wolfgang Denk
2008-02-15 18:18 ` Joakim Tjernlund
2008-02-06 9:59 ` Joakim Tjernlund
2008-02-06 22:11 ` Wolfgang Denk
2008-02-07 0:20 ` Joakim Tjernlund
2008-02-07 16:13 ` Wolfgang Denk
2008-02-04 17:40 ` Timur Tabi
2008-02-04 19:16 ` Wolfgang Denk
2008-02-04 19:24 ` Timur Tabi
2008-02-04 20:36 ` Wolfgang Denk
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