Cross compile kernel w/ buildroot toolchain

Cross compile kernel w/ buildroot toolchain

[Kurt Schwemmer]

I'm trying to figure out a toolchain to use for my system. I can compile
the kernel just fine using the MIPS SDE based distribution, but you
can't cross compile apps with that. I downloaded and built buildroot and
I'm trying to (cross) compile the kernel with it too (I'd like to just
use one compiler for everything). I had it use gcc 3.4.5. When I try to
compile the kernel with:

make
CROSS_COMPILE=~/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-

I eventually get an error while assembling entry.o:
  AS      arch/mips/kernel/entry.o
arch/mips/kernel/entry.S: Assembler messages:
arch/mips/kernel/entry.S:157: Error: opcode not supported on this
processor: mips32 (mips32) `jr.hb $31'
make[1]: *** [arch/mips/kernel/entry.o] Error 1
make: *** [arch/mips/kernel] Error 2

I guess this is a "hazard barrier" instruction. Why doesn't gcc 3.4.5
know about it? What do I need to do to get this to work?

Thanks,
Kurt Schwemmer

Cross compile kernel w/ buildroot toolchain

[Kurt Schwemmer]

I'm trying to figure out a toolchain to use for my system. I can compile
the kernel just fine using the MIPS SDE based distribution, but you
can't cross compile apps with that. I downloaded and built buildroot and
I'm trying to (cross) compile the kernel with it too (I'd like to just
use one compiler for everything). I had it use gcc 3.4.5. When I try to
compile the kernel with:

make
CROSS_COMPILE=~/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-

I eventually get an error while assembling entry.o:
  AS      arch/mips/kernel/entry.o
arch/mips/kernel/entry.S: Assembler messages:
arch/mips/kernel/entry.S:157: Error: opcode not supported on this
processor: mips32 (mips32) `jr.hb $31'
make[1]: *** [arch/mips/kernel/entry.o] Error 1
make: *** [arch/mips/kernel] Error 2

I guess this is a "hazard barrier" instruction. Why doesn't gcc 3.4.5
know about it? What do I need to do to get this to work?

Thanks,
Kurt Schwemmer

Re: Cross compile kernel w/ buildroot toolchain

[Ralf Baechle]

On Mon, Mar 13, 2006 at 01:17:09PM -0700, Kurt Schwemmer wrote:

> I'm trying to figure out a toolchain to use for my system. I can compile
> the kernel just fine using the MIPS SDE based distribution, but you
> can't cross compile apps with that. I downloaded and built buildroot and
> I'm trying to (cross) compile the kernel with it too (I'd like to just
> use one compiler for everything). I had it use gcc 3.4.5. When I try to
> compile the kernel with:
> 
> make
> CROSS_COMPILE=~/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-
> 
> I eventually get an error while assembling entry.o:
>   AS      arch/mips/kernel/entry.o
> arch/mips/kernel/entry.S: Assembler messages:
> arch/mips/kernel/entry.S:157: Error: opcode not supported on this
> processor: mips32 (mips32) `jr.hb $31'
> make[1]: *** [arch/mips/kernel/entry.o] Error 1
> make: *** [arch/mips/kernel] Error 2
> 
> I guess this is a "hazard barrier" instruction. Why doesn't gcc 3.4.5
> know about it? What do I need to do to get this to work?

I'm looking at the latest kernel sources and can't see how this could be
happening.  Which version of the kernel are you trying to build?

  Ralf

RE: Cross compile kernel w/ buildroot toolchain

[Kurt Schwemmer]

I got 2.6.15 "a while back" (>1 month). 

I'll try getting the most recent source. Sorry, I avoided this due to my
company blocking rsync and thus making it a pain to get the sources... 

Thanks,
Kurt

> -----Original Message-----
> From: Ralf Baechle [mailto:ralf@linux-mips.org] 
> Sent: Monday, March 13, 2006 1:33 PM
> To: Kurt Schwemmer
> Cc: linux-mips@linux-mips.org
> Subject: Re: Cross compile kernel w/ buildroot toolchain
> 
> On Mon, Mar 13, 2006 at 01:17:09PM -0700, Kurt Schwemmer wrote:
> 
> > I'm trying to figure out a toolchain to use for my system. I can 
> > compile the kernel just fine using the MIPS SDE based distribution, 
> > but you can't cross compile apps with that. I downloaded and built 
> > buildroot and I'm trying to (cross) compile the kernel with it too 
> > (I'd like to just use one compiler for everything). I had 
> it use gcc 
> > 3.4.5. When I try to compile the kernel with:
> > 
> > make
> > CROSS_COMPILE=~/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-
> > 
> > I eventually get an error while assembling entry.o:
> >   AS      arch/mips/kernel/entry.o
> > arch/mips/kernel/entry.S: Assembler messages:
> > arch/mips/kernel/entry.S:157: Error: opcode not supported on this
> > processor: mips32 (mips32) `jr.hb $31'
> > make[1]: *** [arch/mips/kernel/entry.o] Error 1
> > make: *** [arch/mips/kernel] Error 2
> > 
> > I guess this is a "hazard barrier" instruction. Why doesn't 
> gcc 3.4.5 
> > know about it? What do I need to do to get this to work?
> 
> I'm looking at the latest kernel sources and can't see how 
> this could be happening.  Which version of the kernel are you 
> trying to build?
> 
>   Ralf
> 

RE: Cross compile kernel w/ buildroot toolchain

[Kurt Schwemmer]

I got 2.6.15 "a while back" (>1 month). 

I'll try getting the most recent source. Sorry, I avoided this due to my
company blocking rsync and thus making it a pain to get the sources... 

Thanks,
Kurt

> -----Original Message-----
> From: Ralf Baechle [mailto:ralf@linux-mips.org] 
> Sent: Monday, March 13, 2006 1:33 PM
> To: Kurt Schwemmer
> Cc: linux-mips@linux-mips.org
> Subject: Re: Cross compile kernel w/ buildroot toolchain
> 
> On Mon, Mar 13, 2006 at 01:17:09PM -0700, Kurt Schwemmer wrote:
> 
> > I'm trying to figure out a toolchain to use for my system. I can 
> > compile the kernel just fine using the MIPS SDE based distribution, 
> > but you can't cross compile apps with that. I downloaded and built 
> > buildroot and I'm trying to (cross) compile the kernel with it too 
> > (I'd like to just use one compiler for everything). I had 
> it use gcc 
> > 3.4.5. When I try to compile the kernel with:
> > 
> > make
> > CROSS_COMPILE=~/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-
> > 
> > I eventually get an error while assembling entry.o:
> >   AS      arch/mips/kernel/entry.o
> > arch/mips/kernel/entry.S: Assembler messages:
> > arch/mips/kernel/entry.S:157: Error: opcode not supported on this
> > processor: mips32 (mips32) `jr.hb $31'
> > make[1]: *** [arch/mips/kernel/entry.o] Error 1
> > make: *** [arch/mips/kernel] Error 2
> > 
> > I guess this is a "hazard barrier" instruction. Why doesn't 
> gcc 3.4.5 
> > know about it? What do I need to do to get this to work?
> 
> I'm looking at the latest kernel sources and can't see how 
> this could be happening.  Which version of the kernel are you 
> trying to build?
> 
>   Ralf
> 

Re: Cross compile kernel w/ buildroot toolchain

[Ralf Baechle]

On Mon, Mar 13, 2006 at 01:39:53PM -0700, Kurt Schwemmer wrote:

> I got 2.6.15 "a while back" (>1 month). 
> 
> I'll try getting the most recent source. Sorry, I avoided this due to my
> company blocking rsync and thus making it a pain to get the sources... 

You can still download kernel tarballs from linux-mips.org via ftp and
http; the git repository is accessible through rsync (deprecated), git
and if everything else fails, http.

  Ralf

Re: Cross compile kernel w/ buildroot toolchain

[Thiemo Seufer]

On Mon, Mar 13, 2006 at 01:17:09PM -0700, Kurt Schwemmer wrote:
> I'm trying to figure out a toolchain to use for my system. I can compile
> the kernel just fine using the MIPS SDE based distribution, but you
> can't cross compile apps with that. I downloaded and built buildroot and
> I'm trying to (cross) compile the kernel with it too (I'd like to just
> use one compiler for everything). I had it use gcc 3.4.5. When I try to
> compile the kernel with:
> 
> make
> CROSS_COMPILE=~/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-
> 
> I eventually get an error while assembling entry.o:
>   AS      arch/mips/kernel/entry.o
> arch/mips/kernel/entry.S: Assembler messages:
> arch/mips/kernel/entry.S:157: Error: opcode not supported on this
> processor: mips32 (mips32) `jr.hb $31'
> make[1]: *** [arch/mips/kernel/entry.o] Error 1
> make: *** [arch/mips/kernel] Error 2
> 
> I guess this is a "hazard barrier" instruction. Why doesn't gcc 3.4.5
> know about it? What do I need to do to get this to work?

It is gas which fails, because it either got fed options which don't
enable MIPS32R2, or because your version of binutils is very old and
doesn't know about jr.hb.

Compile with V=1 to find out the actual gcc invocation.


Thiemo

Re: Cross compile kernel w/ buildroot toolchain

[Ralf Baechle]

On Mon, Mar 13, 2006 at 01:39:53PM -0700, Kurt Schwemmer wrote:

> I got 2.6.15 "a while back" (>1 month). 
> 
> I'll try getting the most recent source. Sorry, I avoided this due to my
> company blocking rsync and thus making it a pain to get the sources... 

The reason your case is odd is that the kernel only uses a single
jr.hb instruction which is in the instruction_hazard() macro in
include/asm-mips/hazards.h.  This macro first of all is a gcc inline
assembler macro and also wraps the jr.hb instruction between
.set mips64r2 ... .set mips0, so you should never ever get an error
message.  And you're getting an error message for entry.S, an assembler
file.  Seems you must have done some not so kosher changes to that tree?

  Ralf

RE: Cross compile kernel w/ buildroot toolchain

[Kurt Schwemmer]

I didn't touch any of the source yet. 

I'm downloading the 1/10/05 2.6.15 tarball (
ftp://ftp.linux-mips.org/pub/linux/mips/kernel/v2.6/linux-2.6.15.tar.gz
)now to see if that fixes things.

In response to Thiemo's message the error with (V=1) is:

make -f scripts/Makefile.build obj=arch/mips/kernel
  /klocal/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-gcc
-Wp,-MD,arch/mips/kernel/.entry.o.d  -nostdinc -isystem
/klocal/buildroot/build_mipsel/staging_dir/bin-ccache/../lib/gcc/mipsel-
linux-uclibc/3.4.5/include -D__KERNEL__ -Iinclude  -D__ASSEMBLY__  -I
/usr/local/src/linux-2.6/include/asm/gcc -G 0 -mno-abicalls -fno-pic
-pipe  -finline-limit=100000 -mabi=32 -march=mips32r2 -Wa,-32
-Wa,-march=mips32r2 -Wa,-mips32r2 -Wa,--trap
-Iinclude/asm-mips/mach-mips -Iinclude/asm-mips/mach-generic -Wall
-Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common
-ffreestanding -O2     -fomit-frame-pointer  -I
/usr/local/src/linux-2.6/include/asm/gcc -G 0 -mno-abicalls -fno-pic
-pipe  -finline-limit=100000 -mabi=32 -march=mips32r2 -Wa,-32
-Wa,-march=mips32r2 -Wa,-mips32r2 -Wa,--trap
-Iinclude/asm-mips/mach-mips -Iinclude/asm-mips/mach-generic    -c -o
arch/mips/kernel/entry.o arch/mips/kernel/entry.S
arch/mips/kernel/entry.S: Assembler messages:
arch/mips/kernel/entry.S:157: Error: opcode not supported on this
processor: mips32 (mips32) `jr.hb $31'
make[1]: *** [arch/mips/kernel/entry.o] Error 1
make: *** [arch/mips/kernel] Error 2

Also, assembler -v output:
GNU assembler version 2.16.1 (mipsel-linux-uclibc) using BFD version
2.16.1

Thanks,
Kurt Schwemmer

> -----Original Message-----
> From: Ralf Baechle [mailto:ralf@linux-mips.org] 
> Sent: Monday, March 13, 2006 1:57 PM
> To: Kurt Schwemmer
> Cc: linux-mips@linux-mips.org
> Subject: Re: Cross compile kernel w/ buildroot toolchain
> 
> On Mon, Mar 13, 2006 at 01:39:53PM -0700, Kurt Schwemmer wrote:
> 
> > I got 2.6.15 "a while back" (>1 month). 
> > 
> > I'll try getting the most recent source. Sorry, I avoided 
> this due to 
> > my company blocking rsync and thus making it a pain to get 
> the sources...
> 
> The reason your case is odd is that the kernel only uses a 
> single jr.hb instruction which is in the instruction_hazard() 
> macro in include/asm-mips/hazards.h.  This macro first of all 
> is a gcc inline assembler macro and also wraps the jr.hb 
> instruction between .set mips64r2 ... .set mips0, so you 
> should never ever get an error message.  And you're getting 
> an error message for entry.S, an assembler file.  Seems you 
> must have done some not so kosher changes to that tree?
> 
>   Ralf
> 

RE: Cross compile kernel w/ buildroot toolchain

[Kurt Schwemmer]

I didn't touch any of the source yet. 

I'm downloading the 1/10/05 2.6.15 tarball (
ftp://ftp.linux-mips.org/pub/linux/mips/kernel/v2.6/linux-2.6.15.tar.gz
)now to see if that fixes things.

In response to Thiemo's message the error with (V=1) is:

make -f scripts/Makefile.build obj=arch/mips/kernel
  /klocal/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-gcc
-Wp,-MD,arch/mips/kernel/.entry.o.d  -nostdinc -isystem
/klocal/buildroot/build_mipsel/staging_dir/bin-ccache/../lib/gcc/mipsel-
linux-uclibc/3.4.5/include -D__KERNEL__ -Iinclude  -D__ASSEMBLY__  -I
/usr/local/src/linux-2.6/include/asm/gcc -G 0 -mno-abicalls -fno-pic
-pipe  -finline-limit=100000 -mabi=32 -march=mips32r2 -Wa,-32
-Wa,-march=mips32r2 -Wa,-mips32r2 -Wa,--trap
-Iinclude/asm-mips/mach-mips -Iinclude/asm-mips/mach-generic -Wall
-Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common
-ffreestanding -O2     -fomit-frame-pointer  -I
/usr/local/src/linux-2.6/include/asm/gcc -G 0 -mno-abicalls -fno-pic
-pipe  -finline-limit=100000 -mabi=32 -march=mips32r2 -Wa,-32
-Wa,-march=mips32r2 -Wa,-mips32r2 -Wa,--trap
-Iinclude/asm-mips/mach-mips -Iinclude/asm-mips/mach-generic    -c -o
arch/mips/kernel/entry.o arch/mips/kernel/entry.S
arch/mips/kernel/entry.S: Assembler messages:
arch/mips/kernel/entry.S:157: Error: opcode not supported on this
processor: mips32 (mips32) `jr.hb $31'
make[1]: *** [arch/mips/kernel/entry.o] Error 1
make: *** [arch/mips/kernel] Error 2

Also, assembler -v output:
GNU assembler version 2.16.1 (mipsel-linux-uclibc) using BFD version
2.16.1

Thanks,
Kurt Schwemmer

> -----Original Message-----
> From: Ralf Baechle [mailto:ralf@linux-mips.org] 
> Sent: Monday, March 13, 2006 1:57 PM
> To: Kurt Schwemmer
> Cc: linux-mips@linux-mips.org
> Subject: Re: Cross compile kernel w/ buildroot toolchain
> 
> On Mon, Mar 13, 2006 at 01:39:53PM -0700, Kurt Schwemmer wrote:
> 
> > I got 2.6.15 "a while back" (>1 month). 
> > 
> > I'll try getting the most recent source. Sorry, I avoided 
> this due to 
> > my company blocking rsync and thus making it a pain to get 
> the sources...
> 
> The reason your case is odd is that the kernel only uses a 
> single jr.hb instruction which is in the instruction_hazard() 
> macro in include/asm-mips/hazards.h.  This macro first of all 
> is a gcc inline assembler macro and also wraps the jr.hb 
> instruction between .set mips64r2 ... .set mips0, so you 
> should never ever get an error message.  And you're getting 
> an error message for entry.S, an assembler file.  Seems you 
> must have done some not so kosher changes to that tree?
> 
>   Ralf
> 

Re: Cross compile kernel w/ buildroot toolchain

[David Daney]

Kurt Schwemmer wrote:
> I didn't touch any of the source yet. 
> 
> I'm downloading the 1/10/05 2.6.15 tarball (
> ftp://ftp.linux-mips.org/pub/linux/mips/kernel/v2.6/linux-2.6.15.tar.gz
> )now to see if that fixes things.
> 
> In response to Thiemo's message the error with (V=1) is:
> 
> make -f scripts/Makefile.build obj=arch/mips/kernel
>   /klocal/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-gcc
> -Wp,-MD,arch/mips/kernel/.entry.o.d  -nostdinc -isystem
> /klocal/buildroot/build_mipsel/staging_dir/bin-ccache/../lib/gcc/mipsel-
> linux-uclibc/3.4.5/include -D__KERNEL__ -Iinclude  -D__ASSEMBLY__  -I
> /usr/local/src/linux-2.6/include/asm/gcc -G 0 -mno-abicalls -fno-pic
> -pipe  -finline-limit=100000 -mabi=32 -march=mips32r2 -Wa,-32
> -Wa,-march=mips32r2 -Wa,-mips32r2 -Wa,--trap
> -Iinclude/asm-mips/mach-mips -Iinclude/asm-mips/mach-generic -Wall
> -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common
> -ffreestanding -O2     -fomit-frame-pointer  -I
> /usr/local/src/linux-2.6/include/asm/gcc -G 0 -mno-abicalls -fno-pic
> -pipe  -finline-limit=100000 -mabi=32 -march=mips32r2 -Wa,-32
> -Wa,-march=mips32r2 -Wa,-mips32r2 -Wa,--trap
> -Iinclude/asm-mips/mach-mips -Iinclude/asm-mips/mach-generic    -c -o
> arch/mips/kernel/entry.o arch/mips/kernel/entry.S
> arch/mips/kernel/entry.S: Assembler messages:
> arch/mips/kernel/entry.S:157: Error: opcode not supported on this
> processor: mips32 (mips32) `jr.hb $31'
> make[1]: *** [arch/mips/kernel/entry.o] Error 1
> make: *** [arch/mips/kernel] Error 2
> 
> Also, assembler -v output:
> GNU assembler version 2.16.1 (mipsel-linux-uclibc) using BFD version
> 2.16.1
> 
> Thanks,
> Kurt Schwemmer
> 

You could try using crosstool to generate the compiler instead of buildroot.

Also try passing -v to gcc, that will cause it to show the exact options 
that it is passing to gas.  Perhaps that would shed some light on things.

David Daney

Re: Cross compile kernel w/ buildroot toolchain

[Thiemo Seufer]

On Mon, Mar 13, 2006 at 02:07:34PM -0700, Kurt Schwemmer wrote:
> I didn't touch any of the source yet. 

Hm, are you sure? Because...

> make -f scripts/Makefile.build obj=arch/mips/kernel
>   /klocal/buildroot/build_mipsel/staging_dir/bin/mipsel-linux-gcc
> -Wp,-MD,arch/mips/kernel/.entry.o.d  -nostdinc -isystem
> /klocal/buildroot/build_mipsel/staging_dir/bin-ccache/../lib/gcc/mipsel-
> linux-uclibc/3.4.5/include -D__KERNEL__ -Iinclude  -D__ASSEMBLY__  -I
> /usr/local/src/linux-2.6/include/asm/gcc -G 0 -mno-abicalls -fno-pic
> -pipe  -finline-limit=100000 -mabi=32 -march=mips32r2 -Wa,-32
> -Wa,-march=mips32r2 -Wa,-mips32r2 -Wa,--trap
> -Iinclude/asm-mips/mach-mips -Iinclude/asm-mips/mach-generic -Wall
> -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common
> -ffreestanding -O2     -fomit-frame-pointer  -I
> /usr/local/src/linux-2.6/include/asm/gcc -G 0 -mno-abicalls -fno-pic
> -pipe  -finline-limit=100000 -mabi=32 -march=mips32r2 -Wa,-32
> -Wa,-march=mips32r2 -Wa,-mips32r2 -Wa,--trap
> -Iinclude/asm-mips/mach-mips -Iinclude/asm-mips/mach-generic    -c -o
> arch/mips/kernel/entry.o arch/mips/kernel/entry.S
> arch/mips/kernel/entry.S: Assembler messages:
> arch/mips/kernel/entry.S:157: Error: opcode not supported on this
> processor: mips32 (mips32) `jr.hb $31'

... arch/mips/kernel/entry.S has only 147 lines in the copy I see.

> make[1]: *** [arch/mips/kernel/entry.o] Error 1
> make: *** [arch/mips/kernel] Error 2
> 
> Also, assembler -v output:
> GNU assembler version 2.16.1 (mipsel-linux-uclibc) using BFD version
> 2.16.1

What's also weird is that gas gets the mips32r2 option fed four times
(just to make sure?) and still claims it got mips32 (r1) in the error
message.


Thiemo

RE: Cross compile kernel w/ buildroot toolchain

[Kurt Schwemmer]

Getting the _very_ latest source fixed my problem. I can now build the
kernel with the cross compiler that buildroot builds. Thanks to all who
offered advice!

Thanks,
Kurt Schwemmer 

> -----Original Message-----
> From: Ralf Baechle [mailto:ralf@linux-mips.org] 
> Sent: Monday, March 13, 2006 1:57 PM
> To: Kurt Schwemmer
> Cc: linux-mips@linux-mips.org
> Subject: Re: Cross compile kernel w/ buildroot toolchain
> 
> On Mon, Mar 13, 2006 at 01:39:53PM -0700, Kurt Schwemmer wrote:
> 
> > I got 2.6.15 "a while back" (>1 month). 
> > 
> > I'll try getting the most recent source. Sorry, I avoided 
> this due to 
> > my company blocking rsync and thus making it a pain to get 
> the sources...
> 
> The reason your case is odd is that the kernel only uses a 
> single jr.hb instruction which is in the instruction_hazard() 
> macro in include/asm-mips/hazards.h.  This macro first of all 
> is a gcc inline assembler macro and also wraps the jr.hb 
> instruction between .set mips64r2 ... .set mips0, so you 
> should never ever get an error message.  And you're getting 
> an error message for entry.S, an assembler file.  Seems you 
> must have done some not so kosher changes to that tree?
> 
>   Ralf
> 

RE: Cross compile kernel w/ buildroot toolchain

[Kurt Schwemmer]

Getting the _very_ latest source fixed my problem. I can now build the
kernel with the cross compiler that buildroot builds. Thanks to all who
offered advice!

Thanks,
Kurt Schwemmer 

> -----Original Message-----
> From: Ralf Baechle [mailto:ralf@linux-mips.org] 
> Sent: Monday, March 13, 2006 1:57 PM
> To: Kurt Schwemmer
> Cc: linux-mips@linux-mips.org
> Subject: Re: Cross compile kernel w/ buildroot toolchain
> 
> On Mon, Mar 13, 2006 at 01:39:53PM -0700, Kurt Schwemmer wrote:
> 
> > I got 2.6.15 "a while back" (>1 month). 
> > 
> > I'll try getting the most recent source. Sorry, I avoided 
> this due to 
> > my company blocking rsync and thus making it a pain to get 
> the sources...
> 
> The reason your case is odd is that the kernel only uses a 
> single jr.hb instruction which is in the instruction_hazard() 
> macro in include/asm-mips/hazards.h.  This macro first of all 
> is a gcc inline assembler macro and also wraps the jr.hb 
> instruction between .set mips64r2 ... .set mips0, so you 
> should never ever get an error message.  And you're getting 
> an error message for entry.S, an assembler file.  Seems you 
> must have done some not so kosher changes to that tree?
> 
>   Ralf
>