Re: Question: LTO and failing objcopy in "u-boot-initial-env" target

22 Oct 2021

On Fri, Oct 22, 2021 at 10:16 AM Patrick DELAUNAY
patrick.delaunay@foss.st.com wrote:
...
Hi,
I made tests with LTO option activated on stm32mp15 boards but if have a
issue
with the U-Boot target  "u-boot-initial-env" (this command used by YOCTO)
$> make u-boot-initial-env
...
GENENV  u-boot-initial-env
arm-none-linux-gnueabihf-objcopy: env/common.o: can't dump section
'.rodata.default_environment' - it does not exist: file format not
recognized
sed: can't read u-boot-initial-env: No such file or directory
make[1]: *** [/local/home/frq07632/views/u-boot/Makefile:2315:
u-boot-initial-env] Error 2
make[1]: Leaving directory
'/local/home/frq07632/views/build/stm32mp15_defconfig'
make: *** [Makefile:177: sub-make] Error 2
But I reproduced it with sandbox:
$> make sandbox_defconfig
$> make all
$> make u-boot-initial-env
....
LTO     u-boot
   OBJCOPY u-boot-nodtb.bin
   COPY    u-boot.bin
   GENENV  u-boot-initial-env
objcopy: env/common.o: can't dump section '.rodata.default_environment'

it does not exist: file format not recognized

sed: can't read u-boot-initial-env: No such file or directory
make: *** [Makefile:2315: u-boot-initial-env] Error 2
Do you already know this issue for other board which activate the LTO
feature ?
I don't see any remarks about this issue on mailing list.
Today I am known how to solve this issue.
I ran this:
arm-linux-gnueabihf-objdump env/common.o -t |grep default_environment
|awk '{print $4}'
to generate the name of the section:
.gnu.lto_default_environment.188.408aacacdb8e4907
I modified the Makefile to search for default_environment, then use
output of that as a parameter to $OBJCOPY, and that appears to work.
=====

diff --git a/Makefile b/Makefile
index 5194e4dc78..a80cf94ba1 100644
--- a/Makefile
+++ b/Makefile
@@ -2303,7 +2303,7 @@ endif
        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV  $@
-cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@
env/common.o; \
+cmd_genenv = $(OBJCOPY) --dump-section `${OBJDUMP} env/common.o -t
|grep default_environment |awk '{print $$4}'`=$@ env/common.o; \
        sed --in-place -e 's/\x00/\x0A/g' $@
u-boot-initial-env: u-boot.bin
=====
...
make -f ./scripts/Makefile.build obj=arch/arm/dts dtbs
test -e arch/arm/dts/logicpd-torpedo-37xx-devkit.dtb || ( \
echo >&2; \
echo >&2 "Device Tree Source
(arch/arm/dts/logicpd-torpedo-37xx-devkit.dtb) is not correctly
specified."; \
echo >&2 "Please define 'CONFIG_DEFAULT_DEVICE_TREE'"; \
echo >&2 "or build with 'DEVICE_TREE=<device_tree>' argument"; \
echo >&2; \
/bin/false)
  cat u-boot-nodtb.bin dts/dt.dtb > u-boot-dtb.bin
  cp u-boot-dtb.bin u-boot.bin
  arm-linux-gnueabihf-objcopy --dump-section
`arm-linux-gnueabihf-objdump env/common.o -t |grep default_environment
|awk '{print $4}'`=u-boot-initial-env env/common.o; sed --in-place -e
's/\x00/\x0A/g' u-boot-initial-env
$ ls -l u-boot-initial-env
-rw-rw-r-- 1 aford aford 1202 Oct 22 14:16 u-boot-initial-env
I am not sure it's the right solution, but it appears to work for me
on a board that uses LTO.  I didn't try it with a board that doesn't
use LTO.
adam
...
PS: The same command is executed in "scripts/get_default_envs.sh"
Regards
Patrick
I am ussing gcc 10.2
gcc version 10.2.1 20201103 (GNU Toolchain for the A-profile
Architecture 10.2-2020.11 (arm-10.16))
And the name of the section change with LTO: .gnu.lto_default_environment.*
for exmaple:
$> arm-none-linux-gnueabihf-objdump -x -g -S common.o
common.o:     file format elf32-littlearm
common.o
architecture: armv7, flags 0x00000011:
HAS_RELOC, HAS_SYMS
start address 0x00000000
private flags = 5000000: [Version5 EABI]
Sections:
Idx Name          Size      VMA       LMA       File off  Algn
   0 .text         00000000  00000000  00000000  00000034  2**0
                   CONTENTS, ALLOC, LOAD, READONLY, CODE
   1 .data         00000000  00000000  00000000  00000034  2**0
                   CONTENTS, ALLOC, LOAD, DATA
   2 .bss          00000000  00000000  00000000  00000034  2**0
                   ALLOC
   3 .gnu.debuglto_.debug_info 000010a5  00000000  00000000 00000034  2**0
                   CONTENTS, RELOC, READONLY, EXCLUDE
   4 .gnu.debuglto_.debug_abbrev 000002a1  00000000  00000000 000010d9  2**0
                   CONTENTS, READONLY, EXCLUDE
   5 .gnu.debuglto_.debug_line 00000214  00000000  00000000 0000137a  2**0
                   CONTENTS, READONLY, EXCLUDE
   6 .gnu.debuglto_.debug_str 000012e3  00000000  00000000 0000158e  2**0
                   CONTENTS, READONLY, EXCLUDE
   7 .gnu.lto_.profile.69d69ac49136740e 0000000b  00000000 00000000
00002871  2**0
                   CONTENTS, READONLY, EXCLUDE
   8 .gnu.lto_.icf.69d69ac49136740e 0000007b  00000000  00000000
0000287c  2**0
                   CONTENTS, READONLY, EXCLUDE
   9 .gnu.lto_.ipa_sra.69d69ac49136740e 0000008c  00000000 00000000
000028f7  2**0
                   CONTENTS, READONLY, EXCLUDE
  10 .gnu.lto_.inline.69d69ac49136740e 000002bc  00000000 00000000
00002983  2**0
                   CONTENTS, READONLY, EXCLUDE
  11 .gnu.lto_.jmpfuncs.69d69ac49136740e 0000031c  00000000 00000000
00002c3f  2**0
                   CONTENTS, READONLY, EXCLUDE
  12 .gnu.lto_.pureconst.69d69ac49136740e 0000002f  00000000 00000000
00002f5b  2**0
                   CONTENTS, READONLY, EXCLUDE
  13 .gnu.lto_.lto.69d69ac49136740e 00000008  00000000  00000000
00002f8a  2**0
                   CONTENTS, READONLY, EXCLUDE
  14 .gnu.lto_default_environment.154.69d69ac49136740e 00000507
00000000  00000000  00002f92  2**0
                   CONTENTS, READONLY, EXCLUDE
  15 .gnu.lto_env_htab.155.69d69ac49136740e 00000062  00000000 00000000
00003499  2**0
                   CONTENTS, READONLY, EXCLUDE
  16 .gnu.lto_env_get_yesno.156.69d69ac49136740e 00000244 00000000
00000000  000034fb  2**0
                   CONTENTS, READONLY, EXCLUDE
  17 .gnu.lto_env_get_default.157.69d69ac49136740e 000003dc 00000000
00000000  0000373f  2**0
                   CONTENTS, READONLY, EXCLUDE
  18 .gnu.lto_env_set_default.158.69d69ac49136740e 000004bf 00000000
00000000  00003b1b  2**0
                   CONTENTS, READONLY, EXCLUDE
  19 .gnu.lto_env_set_default_vars.159.69d69ac49136740e 000001c1
00000000  00000000  00003fda  2**0
                   CONTENTS, READONLY, EXCLUDE
  20 .gnu.lto_env_import.160.69d69ac49136740e 00000582  00000000
00000000  0000419b  2**0
                   CONTENTS, READONLY, EXCLUDE
  21 .gnu.lto_env_check_redund.162.69d69ac49136740e 0000088a 00000000
00000000  0000471d  2**0
                   CONTENTS, READONLY, EXCLUDE
  22 .gnu.lto_env_import_redund.163.69d69ac49136740e 00000461 00000000
00000000  00004fa7  2**0
                   CONTENTS, READONLY, EXCLUDE
  23 .gnu.lto_env_export.164.69d69ac49136740e 000003a0  00000000
00000000  00005408  2**0
                   CONTENTS, READONLY, EXCLUDE
  24 .gnu.lto_env_relocate.165.69d69ac49136740e 00000231  00000000
00000000  000057a8  2**0
                   CONTENTS, READONLY, EXCLUDE
  25 .gnu.lto_env_complete.166.69d69ac49136740e 00000880  00000000
00000000  000059d9  2**0
                   CONTENTS, READONLY, EXCLUDE
  26 .gnu.lto_env_relocate.part.0.203.69d69ac49136740e 000001ab
00000000  00000000  00006259  2**0
                   CONTENTS, READONLY, EXCLUDE
  27 .gnu.lto_.symbol_nodes.69d69ac49136740e 000001f2  00000000
00000000  00006404  2**0
                   CONTENTS, READONLY, EXCLUDE
  28 .gnu.lto_.refs.69d69ac49136740e 0000004f  00000000  00000000
000065f6  2**0
                   CONTENTS, READONLY, EXCLUDE
  29 .gnu.lto_.decls.69d69ac49136740e 00001fbf  00000000  00000000
00006645  2**0
                   CONTENTS, READONLY, EXCLUDE
  30 .gnu.lto_.symtab.69d69ac49136740e 000002de  00000000 00000000
00008604  2**0
                   CONTENTS, READONLY, EXCLUDE
  31 .gnu.lto_.ext_symtab.69d69ac49136740e 00000039  00000000 00000000
000088e2  2**0
                   CONTENTS, READONLY, EXCLUDE
  32 .gnu.lto_.opts 000001d6  00000000  00000000  0000891b  2**0
                   CONTENTS, READONLY, EXCLUDE
  33 .comment      0000005e  00000000  00000000  00008af1  2**0
                   CONTENTS, READONLY
  34 .note.GNU-stack 00000000  00000000  00000000  00008b4f  2**0
                   CONTENTS, READONLY
  35 .ARM.attributes 00000031  00000000  00000000  00008b4f  2**0
                   CONTENTS, READONLY
SYMBOL TABLE:
00000000 l    df *ABS*    00000000 common.c
00000000 l    d  .text    00000000 .text
00000000 l    d  .data    00000000 .data
00000000 l    d  .bss    00000000 .bss
00000000 l    d  .gnu.debuglto_.debug_info    00000000
.gnu.debuglto_.debug_info
00000000 l    d  .gnu.debuglto_.debug_abbrev    00000000
.gnu.debuglto_.debug_abbrev
00000000 l    d  .gnu.debuglto_.debug_line    00000000
.gnu.debuglto_.debug_line
00000000 l    d  .gnu.debuglto_.debug_str    00000000
.gnu.debuglto_.debug_str
00000000 l    d  .gnu.lto_.profile.69d69ac49136740e    00000000
.gnu.lto_.profile.69d69ac49136740e
00000000 l    d  .gnu.lto_.icf.69d69ac49136740e    00000000
.gnu.lto_.icf.69d69ac49136740e
00000000 l    d  .gnu.lto_.ipa_sra.69d69ac49136740e    00000000
.gnu.lto_.ipa_sra.69d69ac49136740e
00000000 l    d  .gnu.lto_.inline.69d69ac49136740e    00000000
.gnu.lto_.inline.69d69ac49136740e
00000000 l    d  .gnu.lto_.jmpfuncs.69d69ac49136740e    00000000
.gnu.lto_.jmpfuncs.69d69ac49136740e
00000000 l    d  .gnu.lto_.pureconst.69d69ac49136740e    00000000
.gnu.lto_.pureconst.69d69ac49136740e
00000000 l    d  .gnu.lto_.lto.69d69ac49136740e    00000000
.gnu.lto_.lto.69d69ac49136740e
00000000 l    d .gnu.lto_default_environment.154.69d69ac49136740e
00000000 .gnu.lto_default_environment.154.69d69ac49136740e
00000000 l    d  .gnu.lto_env_htab.155.69d69ac49136740e00000000
.gnu.lto_env_htab.155.69d69ac49136740e
00000000 l    d  .gnu.lto_env_get_yesno.156.69d69ac49136740e 00000000
.gnu.lto_env_get_yesno.156.69d69ac49136740e
00000000 l    d  .gnu.lto_env_get_default.157.69d69ac49136740e 00000000
.gnu.lto_env_get_default.157.69d69ac49136740e
00000000 l    d  .gnu.lto_env_set_default.158.69d69ac49136740e 00000000
.gnu.lto_env_set_default.158.69d69ac49136740e
00000000 l    d .gnu.lto_env_set_default_vars.159.69d69ac49136740e
00000000 .gnu.lto_env_set_default_vars.159.69d69ac49136740e
00000000 l    d  .gnu.lto_env_import.160.69d69ac49136740e 00000000
.gnu.lto_env_import.160.69d69ac49136740e
00000000 l    d  .gnu.lto_env_check_redund.162.69d69ac49136740e 00000000
.gnu.lto_env_check_redund.162.69d69ac49136740e
00000000 l    d .gnu.lto_env_import_redund.163.69d69ac49136740e
00000000 .gnu.lto_env_import_redund.163.69d69ac49136740e
00000000 l    d  .gnu.lto_env_export.164.69d69ac49136740e 00000000
.gnu.lto_env_export.164.69d69ac49136740e
00000000 l    d  .gnu.lto_env_relocate.165.69d69ac49136740e 00000000
.gnu.lto_env_relocate.165.69d69ac49136740e
00000000 l    d  .gnu.lto_env_complete.166.69d69ac49136740e 00000000
.gnu.lto_env_complete.166.69d69ac49136740e
00000000 l    d .gnu.lto_env_relocate.part.0.203.69d69ac49136740e
00000000 .gnu.lto_env_relocate.part.0.203.69d69ac49136740e
00000000 l    d  .gnu.lto_.symbol_nodes.69d69ac49136740e 00000000
.gnu.lto_.symbol_nodes.69d69ac49136740e
00000000 l    d  .gnu.lto_.refs.69d69ac49136740e    00000000
.gnu.lto_.refs.69d69ac49136740e
00000000 l    d  .gnu.lto_.decls.69d69ac49136740e    00000000
.gnu.lto_.decls.69d69ac49136740e
00000000 l    d  .gnu.lto_.symtab.69d69ac49136740e    00000000
.gnu.lto_.symtab.69d69ac49136740e
00000000 l    d  .gnu.lto_.ext_symtab.69d69ac49136740e    00000000
.gnu.lto_.ext_symtab.69d69ac49136740e
00000000 l    d  .gnu.lto_.opts    00000000 .gnu.lto_.opts
00000000 l    d  .note.GNU-stack    00000000 .note.GNU-stack
00000000 l    d  .comment    00000000 .comment
00000000 l    d  .ARM.attributes    00000000 .ARM.attributes
00000000  w      .gnu.debuglto_.debug_info    00000000 .hidden
common.c.2c9afba8
00000001       O *COM*    00000001 __gnu_lto_slim

    

Re: Question: LTO and failing objcopy in "u-boot-initial-env" target

Adam Ford