[PATCH] Makefile: fix u-boot-initial-env target if lto is enabled
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
---
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \ + $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \ + sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \ + sort --field-separator== -k1,1 --stable $@ -o $@; \ + rm -f env/initial_env.o env/initial_env.su +else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \ sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \ sort --field-separator== -k1,1 --stable $@ -o $@ +endif
u-boot-initial-env: u-boot.bin $(call if_changed,genenv)
On Tue, Oct 18, 2022 at 07:48:27PM +0200, Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
- $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \
- sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
- sort --field-separator== -k1,1 --stable $@ -o $@; \
- rm -f env/initial_env.o env/initial_env.su
+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \ sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \ sort --field-separator== -k1,1 --stable $@ -o $@ +endif
u-boot-initial-env: u-boot.bin $(call if_changed,genenv)
Can we pipe the output instead of making a new object file? Maybe not, in a portable way it seems. But, I'm not sure the above respects using O= as well so that does need to be checked and fixed if so.
Hi Tom
On Tue, Oct 18, 2022 at 7:57 PM Tom Rini trini@konsulko.com wrote:
On Tue, Oct 18, 2022 at 07:48:27PM +0200, Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
$(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \sort --field-separator== -k1,1 --stable $@ -o $@; \rm -f env/initial_env.o env/initial_env.su+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \ sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \ sort --field-separator== -k1,1 --stable $@ -o $@ +endif
u-boot-initial-env: u-boot.bin $(call if_changed,genenv)
Can we pipe the output instead of making a new object file? Maybe not, in a portable way it seems. But, I'm not sure the above respects using O= as well so that does need to be checked and fixed if so.
While I didn't test it seems that objcopy doesn't allow to pipe data in and out of it.
Max
-- Tom
On Wednesday 19 October 2022 14:59:49 Max Krummenacher wrote:
Hi Tom
On Tue, Oct 18, 2022 at 7:57 PM Tom Rini trini@konsulko.com wrote:
On Tue, Oct 18, 2022 at 07:48:27PM +0200, Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
$(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \sort --field-separator== -k1,1 --stable $@ -o $@; \rm -f env/initial_env.o env/initial_env.su+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \ sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \ sort --field-separator== -k1,1 --stable $@ -o $@ +endif
u-boot-initial-env: u-boot.bin $(call if_changed,genenv)
Can we pipe the output instead of making a new object file? Maybe not, in a portable way it seems. But, I'm not sure the above respects using O= as well so that does need to be checked and fixed if so.
While I didn't test it seems that objcopy doesn't allow to pipe data in and out of it.
I think it should be easier to compile a new application which includes header file with env data and prints it to stdout. There are already host tools like mkimage which are run during u-boot build process, so adding a new simple host tool should not be a problem -- instead of trying to hack objcopy, or try to find a way how to play with its input/output redirection and symbol names to achieve same thing.
Max
-- Tom
On Tuesday 18 October 2022 19:48:27 Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
- $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \
- sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
- sort --field-separator== -k1,1 --stable $@ -o $@; \
- rm -f env/initial_env.o env/initial_env.su
+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
This code is still broken because in some cases section name is not RO.
So instead of using section name, I would rather suggest to compile simple host application which prints it.
sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \ sort --field-separator== -k1,1 --stable $@ -o $@ +endif
u-boot-initial-env: u-boot.bin $(call if_changed,genenv) -- 2.35.3
On Tue, Oct 18, 2022 at 08:03:31PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 19:48:27 Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
- $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \
- sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
- sort --field-separator== -k1,1 --stable $@ -o $@; \
- rm -f env/initial_env.o env/initial_env.su
+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
This code is still broken because in some cases section name is not RO.
Wait, when does that happen?
On Tuesday 18 October 2022 14:04:46 Tom Rini wrote:
On Tue, Oct 18, 2022 at 08:03:31PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 19:48:27 Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
- $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \
- sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
- sort --field-separator== -k1,1 --stable $@ -o $@; \
- rm -f env/initial_env.o env/initial_env.su
+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
This code is still broken because in some cases section name is not RO.
Wait, when does that happen?
-- Tom
E.g. for mvebu_espressobin-88f3720_defconfig
On Tue, Oct 18, 2022 at 08:06:27PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 14:04:46 Tom Rini wrote:
On Tue, Oct 18, 2022 at 08:03:31PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 19:48:27 Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
- $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \
- sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
- sort --field-separator== -k1,1 --stable $@ -o $@; \
- rm -f env/initial_env.o env/initial_env.su
+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
This code is still broken because in some cases section name is not RO.
Wait, when does that happen?
E.g. for mvebu_espressobin-88f3720_defconfig
Erm, ugh. I see 44be835d25ba ("arm: mvebu: Espressobin: Set default value for $ethNaddr env variable") and c4df0f6f315c ("arm: mvebu: Espressobin: Set default value for $fdtfile env variable") I guess we couldn't solve this any other way? The platforms aren't unique in needing / wanting to set MAC or fdtfile variables.
On Tuesday 18 October 2022 14:17:23 Tom Rini wrote:
On Tue, Oct 18, 2022 at 08:06:27PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 14:04:46 Tom Rini wrote:
On Tue, Oct 18, 2022 at 08:03:31PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 19:48:27 Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
- $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \
- sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
- sort --field-separator== -k1,1 --stable $@ -o $@; \
- rm -f env/initial_env.o env/initial_env.su
+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
This code is still broken because in some cases section name is not RO.
Wait, when does that happen?
E.g. for mvebu_espressobin-88f3720_defconfig
Erm, ugh. I see 44be835d25ba ("arm: mvebu: Espressobin: Set default value for $ethNaddr env variable") and c4df0f6f315c ("arm: mvebu: Espressobin: Set default value for $fdtfile env variable") I guess we couldn't solve this any other way? The platforms aren't unique in needing / wanting to set MAC or fdtfile variables.
-- Tom
Yes, we can solve it. Marek was working on solution for setting default variables at runtime but seems it is not finished yet.
On Tue, Oct 18, 2022 at 08:19:23PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 14:17:23 Tom Rini wrote:
On Tue, Oct 18, 2022 at 08:06:27PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 14:04:46 Tom Rini wrote:
On Tue, Oct 18, 2022 at 08:03:31PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 19:48:27 Max Krummenacher wrote:
From: Max Krummenacher max.krummenacher@toradex.com
With LTO enabled the U-Boot initial environment is no longer stored in an easy accessible section in env/common.o. I.e. the section name changes from build to build, its content maybe compressed and it is annotated with additional data.
For GCC adding the option '-ffat-lto-objects' when compiling common.o adds additionally the traditional sections in the object file and 'make u-boot-initial-env' would work also for the LTO enabled case. However clang doesn't have that option.
Fix this by recompiling common.o into a object file only used for the creation of u-boot-initial-env if LTO is enabled.
See also: https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com...
Signed-off-by: Max Krummenacher max.krummenacher@toradex.com
Makefile | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Makefile b/Makefile index 3866cc62f9a..cd45c720d23 100644 --- a/Makefile +++ b/Makefile @@ -2451,9 +2451,17 @@ endif $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
quiet_cmd_genenv = GENENV $@ +ifeq ($(LTO_ENABLE),y) +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \
- $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \
- sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \
- sort --field-separator== -k1,1 --stable $@ -o $@; \
- rm -f env/initial_env.o env/initial_env.su
+else cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
This code is still broken because in some cases section name is not RO.
Wait, when does that happen?
E.g. for mvebu_espressobin-88f3720_defconfig
Erm, ugh. I see 44be835d25ba ("arm: mvebu: Espressobin: Set default value for $ethNaddr env variable") and c4df0f6f315c ("arm: mvebu: Espressobin: Set default value for $fdtfile env variable") I guess we couldn't solve this any other way? The platforms aren't unique in needing / wanting to set MAC or fdtfile variables.
Yes, we can solve it. Marek was working on solution for setting default variables at runtime but seems it is not finished yet.
OK, then lets not assume DEFAULT_ENV_IS_RW is something we need to worry about long term.
Hi all
Thanks for the feedback
On Tue, Oct 18, 2022 at 8:23 PM Tom Rini trini@konsulko.com wrote:
On Tue, Oct 18, 2022 at 08:19:23PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 14:17:23 Tom Rini wrote:
On Tue, Oct 18, 2022 at 08:06:27PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 14:04:46 Tom Rini wrote:
On Tue, Oct 18, 2022 at 08:03:31PM +0200, Pali Rohár wrote:
On Tuesday 18 October 2022 19:48:27 Max Krummenacher wrote: > From: Max Krummenacher max.krummenacher@toradex.com > > With LTO enabled the U-Boot initial environment is no longer stored > in an easy accessible section in env/common.o. I.e. the section name > changes from build to build, its content maybe compressed and it is > annotated with additional data. > > For GCC adding the option '-ffat-lto-objects' when compiling common.o > adds additionally the traditional sections in the object file and > 'make u-boot-initial-env' would work also for the LTO enabled case. > However clang doesn't have that option. > > Fix this by recompiling common.o into a object file only used for > the creation of u-boot-initial-env if LTO is enabled. > > See also: > https://lore.kernel.org/all/927b122e-1f62-e790-f5ca-30bae4332c77@foss.st.com... > > Signed-off-by: Max Krummenacher max.krummenacher@toradex.com > > --- > > Makefile | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/Makefile b/Makefile > index 3866cc62f9a..cd45c720d23 100644 > --- a/Makefile > +++ b/Makefile > @@ -2451,9 +2451,17 @@ endif > $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost > > quiet_cmd_genenv = GENENV $@ > +ifeq ($(LTO_ENABLE),y) > +cmd_genenv = $(CC) $(filter-out $(LTO_CFLAGS),$(c_flags)) -c -o env/initial_env.o env/common.c; \ > + $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/initial_env.o; \ > + sed --in-place -e 's/\x00/\x0A/g' $@; sed --in-place -e '/^\s*$$/d' $@; \ > + sort --field-separator== -k1,1 --stable $@ -o $@; \ > + rm -f env/initial_env.o env/initial_env.su > +else > cmd_genenv = $(OBJCOPY) --dump-section .rodata.default_environment=$@ env/common.o; \
This code is still broken because in some cases section name is not RO.
Wait, when does that happen?
E.g. for mvebu_espressobin-88f3720_defconfig
Erm, ugh. I see 44be835d25ba ("arm: mvebu: Espressobin: Set default value for $ethNaddr env variable") and c4df0f6f315c ("arm: mvebu: Espressobin: Set default value for $fdtfile env variable") I guess we couldn't solve this any other way? The platforms aren't unique in needing / wanting to set MAC or fdtfile variables.
Yes, we can solve it. Marek was working on solution for setting default variables at runtime but seems it is not finished yet.
OK, then lets not assume DEFAULT_ENV_IS_RW is something we need to worry about long term.
The patch was intended to fix u-boot-initial-env make target for cases where it worked without 'CONFIG_LTO' to also work if that config gets enabled.
Any use case where it already fails without 'CONFIG_LTO' set will not benefit.
I agree that a variant of tools/env/fw_printenv compiled for the build host may solve additional issues present. However I will not be able to work on such a solution in the near future.
Max
-- Tom
participants (3)
-
Max Krummenacher -
Pali Rohár -
Tom Rini