NPTL compile error without MMU (ARM)

Buildroot Sangjung 3 participants 5 messages Mar 27, 2014

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Sangjung

author

2014-03-27 06:33 UTC #0 lore raw

Dear developers.

Hi. I found out that nptl make a compile error when MMU (i.e. 'Toolchain
- Enable MMU support') is disabled.

Detailed error message is as below.

--------------------------------------------------------------------------------

In file included from libpthread/nptl/sysdeps/unix/sysv/linux/arm/fork.c:31:0:
libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:61:17: error:
'fork' undeclared here (not in a function) libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:63:1: error:
'__libc_fork' redeclared as different kind of symbol libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:61:23: note:
previous declaration of '__libc_fork' was here libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:228:1: error:
'fork' redeclared as different kind of symbol libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:227:1: note:
previous declaration of 'fork' was here libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:229:1: error:
'__EI_fork' aliased to undefined symbol '__GI_fork'
make[1]: *** [libpthread/nptl/sysdeps/unix/sysv/linux/arm/fork.os] Error 1
--------------------------------------------------------------------------------

This problem is already reported by Axel Lin.
(Link: http://lists.uclibc.org/pipermail/uclibc-cvs/2013-May/031094.html)

However, it looks like that this issue is not solved for a long time. If someone let me know the alternative solution, I'd be really happy.

Thank you in advances.

BRs,
Sangjung

Thomas Petazzoni

2014-03-27 06:40 UTC #1 lore raw

Dear Sangjung,

Quoted 26 lines · Sangjung

Dear developers.
Hi. I found out that nptl make a compile error when MMU (i.e. 'Toolchain
- Enable MMU support') is disabled.
Detailed error message is as below.
--------------------------------------------------------------------------------
In file included from libpthread/nptl/sysdeps/unix/sysv/linux/arm/fork.c:31:0:
libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:61:17: error:
'fork' undeclared here (not in a function) libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:63:1: error:
'__libc_fork' redeclared as different kind of symbol libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:61:23: note:
previous declaration of '__libc_fork' was here libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:228:1: error:
'fork' redeclared as different kind of symbol libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:227:1: note:
previous declaration of 'fork' was here libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:229:1: error:
'__EI_fork' aliased to undefined symbol '__GI_fork'
make[1]: *** [libpthread/nptl/sysdeps/unix/sysv/linux/arm/fork.os] Error 1
--------------------------------------------------------------------------------

Quoted 5 lines

This problem is already reported by Axel Lin.
(Link: http://lists.uclibc.org/pipermail/uclibc-cvs/2013-May/031094.html)
However, it looks like that this issue is not solved for a long time. If someone let me know the alternative solution, I'd be really happy.

Thanks for your report. The problem really looks like a uClibc problem, so I would suggest you to take the uClibc configuration file in output/build/uclibc-<version>/.config, and sent the report to the uClibc developers. I am also on the uClibc mailing list, so I will be able to add additional Buildroot-specific details if requested by the uClibc developers.

Outside of this, it is interesting to see that you are looking at the ARM non-MMU support. Do you have an actual hardware platform? In fact, I have been interested by looking into ARM non-MMU support in Buildroot for a long time, but I have never found a hardware platform, or emulated platform, to test things on. If this is something you can help with, I'm pretty sure the ARM non-MMU support would make more significant progress.

Thanks!

Thomas

Signature · 3 lines

Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Sangjung

author

2014-03-27 07:11 UTC #2 lore raw

Dear Thomas.

Quoted 6 lines · Thomas Petazzoni

Thanks for your report. The problem really looks like a uClibc problem, so I would suggest you to take the uClibc configuration file in output/build/uclibc-<version>/.config, and sent the report to the uClibc developers. I am also on the uClibc mailing list, so I will be able to add additional Buildroot-specific details if requested by the uClibc developers.

Thank you for your quick reply.
I will also report this issue to uClibc mailing list ASAP.

Quoted 8 lines

Outside of this, it is interesting to see that you are looking at the ARM non-MMU support. Do you have an actual hardware platform? In fact, I have been interested by looking into ARM non-MMU support in Buildroot for a long time, but I have never found a hardware platform, or emulated platform, to test things on. If this is something you can help with, I'm pretty sure the ARM non-MMU support would make more significant progress.

Our target device is for very small wearable thing. Because of various issue such as power consumption and cost, ARM Cortex M (that is MMU-less) series are commonly used.

BRs
Sangjung

Thomas Petazzoni

2014-03-27 07:21 UTC #3 lore raw

Dear Sangjung,

Quoted 10 lines · Sangjung

Quoted 6 lines · Thomas Petazzoni
Thanks for your report. The problem really looks like a uClibc problem, so I would suggest you to take the uClibc configuration file in output/build/uclibc-<version>/.config, and sent the report to the uClibc developers. I am also on the uClibc mailing list, so I will be able to add additional Buildroot-specific details if requested by the uClibc developers.
Thank you for your quick reply.
I will also report this issue to uClibc mailing list ASAP.

Excellent, thanks!

Quoted 11 lines

Quoted 7 lines
Outside of this, it is interesting to see that you are looking at the ARM non-MMU support. Do you have an actual hardware platform? In fact, I have been interested by looking into ARM non-MMU support in Buildroot for a long time, but I have never found a hardware platform, or emulated platform, to test things on. If this is something you can help with, I'm pretty sure the ARM non-MMU support would make more significant progress.
Our target device is for very small wearable thing. Because of various issue such as power consumption and cost, ARM Cortex M (that is MMU-less) series are commonly used.

So I suppose these platforms have external RAM and Flash, right? Because most of the Cortex-M platforms I've seen have only the internal RAM and Flash of the Cortex-M processor, and the amount available internally is usually not sufficient to run Linux.

Best regards,

Thomas

Signature · 3 lines

Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Sangjung Woo

2014-03-27 14:48 UTC #4 lore raw

In reply to Thomas Petazzoni

Dear Thomas

Quoted 32 lines · Thomas Petazzoni

Dear Sangjung,
Quoted 29 lines · Sangjung
Dear developers.
Hi. I found out that nptl make a compile error when MMU (i.e. 'Toolchain
- Enable MMU support') is disabled.
Detailed error message is as below.
--------------------------------------------------------------------------------
In file included from libpthread/nptl/sysdeps/unix/sysv/linux/arm/fork.c:31:0:
libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:61:17: error:
'fork' undeclared here (not in a function) libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:63:1: error:
'__libc_fork' redeclared as different kind of symbol libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:61:23: note:
previous declaration of '__libc_fork' was here libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:228:1: error:
'fork' redeclared as different kind of symbol libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:227:1: note:
previous declaration of 'fork' was here libpthread/nptl/sysdeps/unix/sysv/linux/arm/../fork.c:229:1: error:
'__EI_fork' aliased to undefined symbol '__GI_fork'
make[1]: *** [libpthread/nptl/sysdeps/unix/sysv/linux/arm/fork.os] Error 1
--------------------------------------------------------------------------------
This problem is already reported by Axel Lin.
(Link: http://lists.uclibc.org/pipermail/uclibc-cvs/2013-May/031094.html)

Quoted 8 lines

Quoted 2 lines
However, it looks like that this issue is not solved for a long time. If someone let me know the alternative solution, I'd be really happy.
Thanks for your report. The problem really looks like a uClibc problem, so I would suggest you to take the uClibc configuration file in output/build/uclibc-<version>/.config, and sent the report to the uClibc developers. I am also on the uClibc mailing list, so I will be able to add additional Buildroot-specific details if requested by the uClibc developers.

After looking into this issue for a while,
in my opinion, buildroot generated the wrong configuration for uclibc.

I also found out that the _SAME_ problem already reported in _uclibc_ Bugzilla.
(URL: https://bugs.uclibc.org/show_bug.cgi?id=6224)

What if you want to reproduce this error, 'qemu_arm_versatile_defconfig' could be used as below. Then, you will face the same errors that I reported.

---------------------------------------------

$ make qemu_arm_versatile_defconfig
Disable MMU (i.e. 'BR2_USE_MMU is not set' in .config)
$ make
---------------------------------------------

If I misunderstood something, let me know it.

BRs
Sangjung.