Hi Christian,

On Thu, Jul 26, 2012 at 10:03 AM, Christian Riesch christian.riesch@omicron.at wrote:

[cc'd Prabhakar Lad, Tom Rini, and Scott Wood]

Tyler,

On Thu, Jul 26, 2012 at 5:37 PM, Tyler Olmstead tyler.j.olmstead@gmail.com wrote:

...

Hi all,

I have encountered some issues adding a board-specific command to the board file of a project I have been working on. Specifically, after adding a U-Boot shell command to my board file, I have been seeing link-stage failures when attempting to build SPL.

It's hard to tell without having your code, but I think this problem was already discussed in [1]. However I do not remember how Prabhakar solved it in the end.

Yes, I ran into this thread while debugging the problem, which ultimately lead me to my solution. From that same thread [1], Wolfgang Denk writes:

<quote>

*I want to add a command using U_BOOT_CMD in uboot, where SPL_BUILD is enabled for example for da850evm in spl frame work how can i do that *

This makes no sense. Commands can only be executed when we have full U-Boot running (actually even only after relocation). You cannot run commands in the SPL. </quote>

I understand of course why it makes no sense to have command support in the SPL. However, the crux of this problem is that U-Boot and SPL both link in the same board object file, so in that sense compile-time switches wont work. From later in [1], Scott Wood writes:

<quote>

Maybe we should poke <command.h> to nop out U_BOOT_CMD for CONFIG_SPL_BUILD? OTOH, #ifndef'ing U_BOOT_CMD and the code itself gets us a space savings we wouldn't get otherwise (I suspect giving the MTD/NAND issue I've mentioned before)...

Commands should be stripped out already with the new SPL -- that's what the (unfortunately uncommented) sed command in GEN_UBOOT appears to be doing.

-Scott </quote>

Unfortunately, this is incorrect. From the ld man page [2]:

-u symbol --undefined=symbol Force symbol to be entered in the output file as an undefined symbol. Doing this may, for example, trigger linking of additional modules from standard libraries. -u may be repeated with different option arguments to enter additional undefined symbols. This option is equivalent to the "EXTERN" linker script command.

Which means that the sed command in GEN_UBOOT in the SPL makefile actually forces the *inclusion* of the command table, and therefore forces the resolution of any undefined symbols in the command function (hence my problem). This same command also appears in the top-level U-Boot makefile, and I find it likely that it was included in the SPL makefile as the result of a copy-paste error. This problem would only arise for commands in object files that are linked into the SPL image, such as the board file.

-- Tyler [2] http://unixhelp.ed.ac.uk/CGI/man-cgi?ld

In [1] I suggested to put an

#ifndef CONFIG_SPL_BUILD U_BOOT_CMD( ... ); #endif

around the command definition in the board file. But also other solutions were discussed in that thread, please have a look.

Regards, Christian

[1] http://marc.info/?t=132748548900003

...

<snip>

UNDEF_SYM=`arm-arago-linux-gnueabi-objdump -x /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/arch/arm/cpu/arm926ejs/davinci/libdavinci.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/arch/arm/cpu/arm926ejs/libarm926ejs.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/arch/arm/lib/libarm.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/board/davinci/da8xxevm/libda8xxevm.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/drivers/mtd/nand/libnand.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/drivers/serial/libserial.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/lib/libgeneric.o | sed -n -e 's/.*(__u_boot_cmd_.*)/-u\1/p'|sort|uniq`; cd /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/ && arm-arago-linux-gnueabi-ld -T /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/u-boot-spl.lds --gc-sections -Bstatic -Ttext 0xc1080000 $UNDEF_SYM arch/arm/cpu/arm926ejs/start.o --start-group arch/arm/cpu/arm926ejs/davinci/libdavinci.o arch/arm/cpu/arm926ejs/libarm926ejs.o arch/arm/lib/libarm.o board/davinci/da8xxevm/libda8xxevm.o drivers/mtd/nand/libnand.o drivers/serial/libserial.o lib/libgeneric.o --end-group /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/arch/arm/lib/eabi_compat.o -L /usr/local/ti-sdk-am180x-evm/linux-devkit/bin/../lib/gcc/arm-arago-linux-gnueabi/4.3.3 -lgcc -Map u-boot-spl.map -o u-boot-spl board/davinci/da8xxevm/libda8xxevm.o: In function `do_mycmd': /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/board/davinci/da8xxevm/awpb3.c:121: undefined reference to `eth_get_dev_by_index' /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/board/davinci/da8xxevm/awpb3.c:123: undefined reference to `eth_write_hwaddr' /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/board/davinci/da8xxevm/awpb3.c:126: undefined reference to `printf' make[1]: *** [/home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/u-boot-spl] Error 1 make[1]: Leaving directory `/home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl' make: *** [spl/u-boot-spl.bin] Error 2

</snip>

In the output above, one can see the environment variable $UNDEF_SYM being defined as the result of the following SPL makefile (spl/Makefile) target:

GEN_UBOOT = \ UNDEF_SYM=`$(OBJDUMP) -x $(LIBS) | \ sed -n -e 's/.*($(SYM_PREFIX)__u_boot_cmd_.*)/-u\1/p'|sort|uniq`;\ cd $(obj) && $(LD) $(LDFLAGS) $(LDFLAGS_$(@F)) $$UNDEF_SYM $(__START) \ --start-group $(__LIBS) --end-group $(PLATFORM_LIBS) \ -Map u-boot-spl.map -o u-boot-spl

$(obj)u-boot-spl: depend $(START) $(LIBS) $(obj)u-boot-spl.lds $(GEN_UBOOT)

For my target, $UNDEF_SYM expands to the following: -u__u_boot_cmd_mycmd

As I understand it, this is to force the inclusion of the commands into the command table located in the special .u_boot_cmd section so that unreferenced commands are not linked out of the final U-Boot binary. However, I don't think that the inclusion of commands into the SPL is intended. Removing the $UNDEF_SYM variable from the SPL makefile resolves my build issues. I am planning on submitting a patch. Does anyone see a flaw in my thinking?

Thanks, -- Tyler _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot

Hi,

On Thursday, July 26, 2012, Aneesh V wrote:

Hi Tyler,

On 07/26/2012 11:54 AM, Tyler Olmstead wrote:

...

Hi Christian,

On Thu, Jul 26, 2012 at 10:03 AM, Christian Riesch christian.riesch@omicron.at wrote:

...

[cc'd Prabhakar Lad, Tom Rini, and Scott Wood]

Tyler,

On Thu, Jul 26, 2012 at 5:37 PM, Tyler Olmstead tyler.j.olmstead@gmail.com wrote:

...

Hi all,

I have encountered some issues adding a board-specific command to the board file of a project I have been working on. Specifically, after adding a U-Boot shell command to my board file, I have been seeing link-stage failures when attempting to build SPL.

It's hard to tell without having your code, but I think this problem was already discussed in [1]. However I do not remember how Prabhakar solved it in the end.

Yes, I ran into this thread while debugging the problem, which ultimately lead me to my solution. From that same thread [1], Wolfgang Denk writes:

<quote>

...

*I want to add a command using U_BOOT_CMD in uboot, where SPL_BUILD is enabled for example for da850evm in spl frame work how can i do that *

This makes no sense. Commands can only be executed when we have full U-Boot running (actually even only after relocation). You cannot run commands in the SPL.

</quote>

I understand of course why it makes no sense to have command support in the SPL. However, the crux of this problem is that U-Boot and SPL both link in the same board object file, so in that sense compile-time switches wont work. From later in [1], Scott Wood writes:

No that's not correct. For SPL we build the object files into a different directory "spl/". Please see the below in spl/Makefile

# We want the final binaries in this directory obj := $(OBJTREE)/spl/

Object files used for U-Boot and SPL are not the same. You can use compile-time switches and it should work just fine.

Thanks for pointing that out, Aneesh.

Therefore an #ifndef CONFIG_SPL_BUILD would work for Tyler's problem and I think that it's also easier to read than some build magic that removes u-boot commands.

Christian

-Aneesh ______________________________**_________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/**listinfo/u-boothttp://lists.denx.de/mailman/listinfo/u-boot

Hi Tyler,

2012/8/3 Tyler Olmstead tyler.j.olmstead@gmail.com:

Yes, the #ifndef works perfectly for me. However, I also agree with your sentiment regarding build magic, which is why I wonder if removing the $GEN_UBOOT linker magic from the SPL makefile wouldn't be the best approach. If this was done, then my U-Boot command wouldn't have been linked into SPL in the first place, it wouldn't require any cluttering of #ifdef's, and would eliminate the potential of others encountering this same problem. This seems reasonable given that SPL shouldn't contain any command support. Thoughts?

Most of the spl/Makefile code was copied and adapted from the top Makefile. Unfortunately, we have not optimized the GEN_UBOOT macro so it still has the UNDEF_SYM magic which is obviously unnecessary.

I would suggest to remove the UNDEF_SYM magic.

Best regards, Daniel

Hi Tyler/Christian,

On Fri, Jul 27, 2012 at 00:24:20, Tyler Olmstead wrote:

Hi Christian,

On Thu, Jul 26, 2012 at 10:03 AM, Christian Riesch christian.riesch@omicron.at wrote:

...

[cc'd Prabhakar Lad, Tom Rini, and Scott Wood]

Tyler,

On Thu, Jul 26, 2012 at 5:37 PM, Tyler Olmstead tyler.j.olmstead@gmail.com wrote:

...

Hi all,

I have encountered some issues adding a board-specific command to the board file of a project I have been working on. Specifically, after adding a U-Boot shell command to my board file, I have been seeing link-stage failures when attempting to build SPL.

It's hard to tell without having your code, but I think this problem was already discussed in [1]. However I do not remember how Prabhakar solved it in the end.

#ifndef CONFIG_SPL_BUILD solved my problem.

Thx, --Prabhakar Lad

Yes, I ran into this thread while debugging the problem, which ultimately lead me to my solution. From that same thread [1], Wolfgang Denk writes:

<quote> > > *I want to add a command using U_BOOT_CMD in uboot, where SPL_BUILD is > enabled for example for da850evm in spl frame work how can i do that *

This makes no sense. Commands can only be executed when we have full U-Boot running (actually even only after relocation). You cannot run commands in the SPL.

</quote>

I understand of course why it makes no sense to have command support in the SPL. However, the crux of this problem is that U-Boot and SPL both link in the same board object file, so in that sense compile-time switches wont work. From later in [1], Scott Wood writes:

<quote> > Maybe we should poke <command.h> to nop out U_BOOT_CMD for > CONFIG_SPL_BUILD? OTOH, #ifndef'ing U_BOOT_CMD and the code itself > gets us a space savings we wouldn't get otherwise (I suspect giving > the MTD/NAND issue I've mentioned before)...

Commands should be stripped out already with the new SPL -- that's what the (unfortunately uncommented) sed command in GEN_UBOOT appears to be doing.

-Scott

</quote>

Unfortunately, this is incorrect. From the ld man page [2]:

-u symbol --undefined=symbol Force symbol to be entered in the output file as an undefined symbol. Doing this may, for example, trigger linking of additional modules from standard libraries. -u may be repeated with different option arguments to enter additional undefined symbols. This option is equivalent to the "EXTERN" linker script command.

Which means that the sed command in GEN_UBOOT in the SPL makefile actually forces the *inclusion* of the command table, and therefore forces the resolution of any undefined symbols in the command function (hence my problem). This same command also appears in the top-level U-Boot makefile, and I find it likely that it was included in the SPL makefile as the result of a copy-paste error. This problem would only arise for commands in object files that are linked into the SPL image, such as the board file.

-- Tyler [2] http://unixhelp.ed.ac.uk/CGI/man-cgi?ld

...

In [1] I suggested to put an

#ifndef CONFIG_SPL_BUILD U_BOOT_CMD( ... ); #endif

around the command definition in the board file. But also other solutions were discussed in that thread, please have a look.

Regards, Christian

[1] http://marc.info/?t=132748548900003

...

<snip>

UNDEF_SYM=`arm-arago-linux-gnueabi-objdump -x /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/arch/arm/cpu/arm926ejs/davinci/libdavinci.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/arch/arm/cpu/arm926ejs/libarm926ejs.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/arch/arm/lib/libarm.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/board/davinci/da8xxevm/libda8xxevm.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/drivers/mtd/nand/libnand.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/drivers/serial/libserial.o /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/lib/libgeneric.o | sed -n -e 's/.*(__u_boot_cmd_.*)/-u\1/p'|sort|uniq`; cd /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/ && arm-arago-linux-gnueabi-ld -T /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/u-boot-spl.lds --gc-sections -Bstatic -Ttext 0xc1080000 $UNDEF_SYM arch/arm/cpu/arm926ejs/start.o --start-group arch/arm/cpu/arm926ejs/davinci/libdavinci.o arch/arm/cpu/arm926ejs/libarm926ejs.o arch/arm/lib/libarm.o board/davinci/da8xxevm/libda8xxevm.o drivers/mtd/nand/libnand.o drivers/serial/libserial.o lib/libgeneric.o --end-group /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/arch/arm/lib/eabi_compat.o -L /usr/local/ti-sdk-am180x-evm/linux-devkit/bin/../lib/gcc/arm-arago-linux-gnueabi/4.3.3 -lgcc -Map u-boot-spl.map -o u-boot-spl board/davinci/da8xxevm/libda8xxevm.o: In function `do_mycmd': /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/board/davinci/da8xxevm/awpb3.c:121: undefined reference to `eth_get_dev_by_index' /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/board/davinci/da8xxevm/awpb3.c:123: undefined reference to `eth_write_hwaddr' /home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/board/davinci/da8xxevm/awpb3.c:126: undefined reference to `printf' make[1]: *** [/home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl/u-boot-spl] Error 1 make[1]: Leaving directory `/home/tolmstead/tolmstead_lab-OptiPlex-380/uboot/uboot_nand/spl' make: *** [spl/u-boot-spl.bin] Error 2

</snip>

In the output above, one can see the environment variable $UNDEF_SYM being defined as the result of the following SPL makefile (spl/Makefile) target:

GEN_UBOOT = \ UNDEF_SYM=`$(OBJDUMP) -x $(LIBS) | \ sed -n -e 's/.*($(SYM_PREFIX)__u_boot_cmd_.*)/-u\1/p'|sort|uniq`;\ cd $(obj) && $(LD) $(LDFLAGS) $(LDFLAGS_$(@F)) $$UNDEF_SYM $(__START) \ --start-group $(__LIBS) --end-group $(PLATFORM_LIBS) \ -Map u-boot-spl.map -o u-boot-spl

$(obj)u-boot-spl: depend $(START) $(LIBS) $(obj)u-boot-spl.lds $(GEN_UBOOT)

For my target, $UNDEF_SYM expands to the following: -u__u_boot_cmd_mycmd

As I understand it, this is to force the inclusion of the commands into the command table located in the special .u_boot_cmd section so that unreferenced commands are not linked out of the final U-Boot binary. However, I don't think that the inclusion of commands into the SPL is intended. Removing the $UNDEF_SYM variable from the SPL makefile resolves my build issues. I am planning on submitting a patch. Does anyone see a flaw in my thinking?

Thanks, -- Tyler _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot