[Buildroot] 'ld' gives "unrecognised emulation mode" during make; gcc-3.4.3

[Buildroot] 'ld' gives "unrecognised emulation mode" during make; gcc-3.4.3

[MikeW]

Am using buildroot-20061031 to build arm926t system,
Toolchain options gcc-3.4.3 (-final), ARM, EABI, binutils-2.16.91.0.7
and have set the GNU target suffix to linux-uclibcgnueabi.
[Host system gcc-3.4.6 20060404]

During building libgcc, I get the message
->>
/home/fred/buildroot/build_arm_nofpu/staging_dir/
 arm-linux-uclibcgnueabi/b in/ld: unrecognised emulation mode: armelf_linux
Supported emulations: armelf_linux_eabi
collect2: ld returned 1 exit status
make[3]: *** [libgcc/./_udivsi3.oS] Error 1
-<<

[Buildroot] 'ld' gives "unrecognised emulation mode" - ARM toolchain unbuildable ??

[MikeW]

MikeW <mw_phil@...> writes:

> 
> Am using buildroot-20061031 to build arm926t system,
> Toolchain options gcc-3.4.3 (-final), ARM, EABI, binutils-2.16.91.0.7
> and have set the GNU target suffix to linux-uclibcgnueabi.
> [Host system gcc-3.4.6 20060404]
> 
> During building libgcc, I get the message
> ->>
> /home/fred/buildroot/build_arm_nofpu/staging_dir/
>  arm-linux-uclibcgnueabi/b in/ld: unrecognised emulation mode:
 armelf_linux
> Supported emulations: armelf_linux_eabi
> collect2: ld returned 1 exit status
> make[3]: *** [libgcc/./_udivsi3.oS] Error 1
> -<<
> 
> From Google, I note that this type of problem is not infrequent
 (for other
> target types), but the usual reponse is 'get the latest version'
 which seems a bit of
> a cop-out, plus I am currently required to use 3.4.3 so
 this does not apply.
> 
> a) any ideas to defeat this problem (not involving 3.4.x, x>3 !)
> b) if it's frequent, how come it's not been resolved once & for all
> 
> Thanks,
> MikeW
> 

This seems to be due to an incompatibility between:
1) toolchain.../gcc-x.x.x/config/arm/linux-elf.h
2) toolchain.../binutils-x.x.x/ld/earmelf_linux_eabi.c

In 1) there is a setting TARGET_LINKER_EMULATION "armelf_linux"
In 2) there is a string (part of a struct initialiser) "armelf_linux_eabi"

so unless I can find matching strings in a version of gcc and ld,
buildroot will never be able to build a toolchain.

But 2) says the file is generated by a shell script, so maybe it's
that script which is to blame !
Or maybe I could just hack 1) to have the correct string.

But that raises the question - how does anyone build an ARM toolchain,
with this incompatibility in place ?

Regards,
MikeW

[Buildroot] 'ld' gives

[MikeW]

MikeW <mw_phil@...> writes:

> During building libgcc, I get the message
> ->>
> /home/fred/buildroot/build_arm_nofpu/staging_dir/
>  arm-linux-uclibcgnueabi/b in/ld: unrecognised emulation mode: armelf_linux
> Supported emulations: armelf_linux_eabi
> collect2: ld returned 1 exit status
> make[3]: *** [libgcc/./_udivsi3.oS] Error 1
> -<<

Fixed by setting GNU target suffix to 'elf-linux' instead.

Regards,
MikeW

[Buildroot] 'ld' gives "unrecognised emulation mode" - ARM toolchain unbuildable ??

[MikeW]

MikeW <mw_phil@...> writes:

> 
> MikeW <mw_phil <at> ...> writes:
> 
> > During building libgcc, I get the message
> > ->>
> > /home/fred/buildroot/build_arm_nofpu/staging_dir/
> >  arm-linux-uclibcgnueabi/b in/ld: unrecognised emulation mode: armelf_linux
> > Supported emulations: armelf_linux_eabi
> > collect2: ld returned 1 exit status
> > make[3]: *** [libgcc/./_udivsi3.oS] Error 1
> > -<<
> 
> Fixed by setting GNU target suffix to 'elf-linux' instead.
> 
> Regards,
> MikeW
> 

Except that objects created by the toolchain have EABI version = 0 !!
I need EABI version = 4 for compatibility :(
So that suggests that I need a target suffix containing '-eabi'.

Any ideas ?

I mean, where is this stuff documented - I've trawled through gcc docs
and not found anything that explains these problems.
I'm presumably not the only person to encounter this issue !

Mike

[Buildroot] 'ld' gives "unrecognised emulation mode" - ARM toolchain unbuildable ??

[Michael K. Edwards]

You probably want to stick to armelf(b)-linux-eabi, since that's
clearly the right thing in later toolchains.  EABI on ARM seems to be
better supported in an up-to-date toolchain combination consisting of
gcc 4.1.1, binutils 2.17.50.0.6, and headers from glibc 2.5 and kernel
2.6.16 or later.  I used crosstool to build a glibc toolchain first,
and am currently grinding through compiling a full glibc/NPTL
userspace with ptxdist, cleaning up all the non-uClibc-specific
issues.  Once I have the kinks worked out of that, I'll be trying a
uClibc version; I'll keep the list posted.

As of gcc 4.1.1, it seems that one still needs this patch to fix up
some include issues:
http://www.kegel.com/crosstool/crosstool-0.42/contrib/2006/crosstool-0.38-add-gcc-4.1-20060210.diff

Also, if your target is big-endian, you need the one-line patch below
so that big-endian is really big-endian.

Cheers,
- Michael

--- gcc-4.1.0/gcc/config/arm/linux-eabi.h       2005-11-15
06:32:13.000000000 -0800
+++ gcc-4.1.0-patched/gcc/config/arm/linux-eabi.h       2006-04-26
22:13:14.000000000 -0700
@@ -48,7 +48,8 @@
 #define SUBTARGET_CPU_DEFAULT TARGET_CPU_arm10tdmi

 #undef SUBTARGET_EXTRA_LINK_SPEC
-#define SUBTARGET_EXTRA_LINK_SPEC " -m armelf_linux_eabi"
+#define SUBTARGET_EXTRA_LINK_SPEC \
+  " %{mbig-endian:-m armelfb_linux_eabi} %{mlittle-endian:-m
armelf_linux_eabi} "

 /* Use ld-linux.so.3 so that it will be possible to run "classic"
    GNU/Linux binaries on an EABI system.  */

[Buildroot] 'ld' gives "unrecognised emulation mode" - ARM toolchain unbuildable ??

[MikeW]

Michael K. Edwards <medwards.linux@...> writes:

> 
> You probably want to stick to armelf(b)-linux-eabi, since that's
> clearly the right thing in later toolchains.  EABI on ARM seems to be
> better supported in an up-to-date toolchain combination consisting of
> gcc 4.1.1, binutils 2.17.50.0.6, and headers from glibc 2.5 and kernel
> 2.6.16 or later.  I used crosstool to build a glibc toolchain first,
> and am currently grinding through compiling a full glibc/NPTL
> userspace with ptxdist, cleaning up all the non-uClibc-specific
> issues.  Once I have the kinks worked out of that, I'll be trying a
> uClibc version; I'll keep the list posted.
> 
> As of gcc 4.1.1, it seems that one still needs this patch to fix up
> some include issues:
>
http://www.kegel.com/crosstool/crosstool-0.42/contrib/2006/crosstool-0.38-add-gcc-4.1-20060210.diff
> 
> Also, if your target is big-endian, you need the one-line patch below
> so that big-endian is really big-endian.
> 
> Cheers,
> - Michael

Many thanks - but I am unable to configure Buildroot to give an EABI
compatible (version != 0) toolchain.
I have now tried also using the most recent GCC and Binutils in the
Buildroot menuconfig options, this using buildroot-20061031.

What is the required 'GNU target suffix' or other setting to enable
EABI operation ? (Obviously I have set 'Target ABI: EABI')

The only target suffix that appears to give a workable toolchain
(i.e. one that doesn't say 'unrecognised emulation mode') 
is 'elf-linux', and that doesn't seem to support EABI (objects built
with it have EABI version 0)

If I use any other target suffix settings in the menuconfig 
(e.g. elf-linux-eabi or even tried elf-linux_eabi) I get:
".../bin/ld: unrecognised emulation mode: armelf_linux
Supported emulations: armelf_linux_eabi" ... but I am unable to
obtain that setting :(

Regards,
Mike

[Buildroot] 'ld' gives "unrecognised emulation mode" - ARM toolchain unbuildable ??

[Michael K. Edwards]

Did I say armelf-linux-eabi?  Silly me.  What's working for me (with
glibc and crosstool) is armelf-linux-gnueabi.  I'm almost done
scrubbing cross-configure problems out of my ptxdist userland and will
start banging on uClibc/buildroot today; I'll let you know what I
find.

Cheers,
- Michael

[Buildroot] 'ld' gives "unrecognised emulation mode" - ARM toolchain unbuildable ??

[MikeW]

Michael K. Edwards <medwards.linux@...> writes:

> 
> Did I say armelf-linux-eabi?  Silly me.  What's working for me (with
> glibc and crosstool) is armelf-linux-gnueabi.  I'm almost done
> scrubbing cross-configure problems out of my ptxdist userland and will
> start banging on uClibc/buildroot today; I'll let you know what I
> find.
> 
> Cheers,
> - Michael
> 

Even that gets rejected as being 'armelf_linux', not 'armelf_linux_eabi'.

Looks to me as if there's a regexp somewhere picking out the subcomponents
of the string, and it's somehow not getting the final '_eabi' section.

But where ... crosstool ?

Regards,
MikeW

[Buildroot] 'ld' gives

[MikeW]

MikeW <mw_phil@...> writes:
>
> But where ... crosstool ?

Except Buildroot doesn't use crosstool.