Advice on compiling GCJ for ARM

Advice on compiling GCJ for ARM

[Josh Marinacci]

I've been trying off and on for a week to build a GCJ compiler for webOS, a Linux variant on ARM, with very little success.  On the bright side I've started to learn more about how the GCC build system works. :) My host machine is Mac OSX 10.6.4, Snow Leopard. I've been able to get GCJ for Mac OSX (darwin) working (though with a few issues), but I can't the cross compiler to even finish compiling.


So my first question is really just a request for advice:  what version of GCC should I start with? Which one is likely to give me the most success? Recent 4.5 builds?  

Second, should I be using glibc or newlib?  

Thanks for any help. If there's already some prebuilt GCJ for ARM binaries I'm willing to try those as well.

Thanks!
	Josh

Blasting forth in three part harmony!

Re: Advice on compiling GCJ for ARM

[Andrew Haley]

On 21/09/10 04:14, Josh Marinacci wrote:

> I've been trying off and on for a week to build a GCJ compiler for
> webOS, a Linux variant on ARM, with very little success.  On the
> bright side I've started to learn more about how the GCC build
> system works. :) My host machine is Mac OSX 10.6.4, Snow
> Leopard. I've been able to get GCJ for Mac OSX (darwin) working
> (though with a few issues), but I can't the cross compiler to even
> finish compiling.

Works for me.  You have to build with the right options.  My setup is

  $ /home/aph/gcc/gcc-4_5-branch/configure --prefix=/home/aph/x-arm/install --target=arm-linux-gnueabi --with-sysroot=/home/aph/x-arm/rootfs-f12/ --with-headers=/home/aph/x-arm/chroot-arm/usr/include/ -disable-libssp --disable-libgomp --disable-libmudflap --disable-multilib --disable-static --disable-sjlj-exceptions --enable-languages=java

> So my first question is really just a request for advice: what
> version of GCC should I start with? Which one is likely to give me
> the most success? Recent 4.5 builds?
> 
> Second, should I be using glibc or newlib?  

glibc.

Andrew.

Re: Advice on compiling GCJ for ARM

[Josh Marinacci]

On Sep 21, 2010, at 4:55 AM, Andrew Haley wrote:

> On 21/09/10 04:14, Josh Marinacci wrote:
> 
>> I've been trying off and on for a week to build a GCJ compiler for
>> webOS, a Linux variant on ARM, with very little success.  On the
>> bright side I've started to learn more about how the GCC build
>> system works. :) My host machine is Mac OSX 10.6.4, Snow
>> Leopard. I've been able to get GCJ for Mac OSX (darwin) working
>> (though with a few issues), but I can't the cross compiler to even
>> finish compiling.
> 
> Works for me.  You have to build with the right options.  My setup is
> 
>  $ /home/aph/gcc/gcc-4_5-branch/configure --prefix=/home/aph/x-arm/install --target=arm-linux-gnueabi --with-sysroot=/home/aph/x-arm/rootfs-f12/ --with-headers=/home/aph/x-arm/chroot-arm/usr/include/ -disable-libssp --disable-libgomp --disable-libmudflap --disable-multilib --disable-static --disable-sjlj-exceptions --enable-languages=java

what version of gcc & glibc are you using?

> 
>> So my first question is really just a request for advice: what
>> version of GCC should I start with? Which one is likely to give me
>> the most success? Recent 4.5 builds?
>> 
>> Second, should I be using glibc or newlib?  
> 
> glibc.
> 
> Andrew.

Blasting forth in three part harmony!

Re: Advice on compiling GCJ for ARM

[Andrew Haley]

On 21/09/10 15:18, Josh Marinacci wrote:
> 
> On Sep 21, 2010, at 4:55 AM, Andrew Haley wrote:
> 
>> On 21/09/10 04:14, Josh Marinacci wrote:
>>
>>> I've been trying off and on for a week to build a GCJ compiler for
>>> webOS, a Linux variant on ARM, with very little success.  On the
>>> bright side I've started to learn more about how the GCC build
>>> system works. :) My host machine is Mac OSX 10.6.4, Snow
>>> Leopard. I've been able to get GCJ for Mac OSX (darwin) working
>>> (though with a few issues), but I can't the cross compiler to even
>>> finish compiling.
>>
>> Works for me.  You have to build with the right options.  My setup is
>>
>>  $ /home/aph/gcc/gcc-4_5-branch/configure --prefix=/home/aph/x-arm/install --target=arm-linux-gnueabi --with-sysroot=/home/aph/x-arm/rootfs-f12/ --with-headers=/home/aph/x-arm/chroot-arm/usr/include/ -disable-libssp --disable-libgomp --disable-libmudflap --disable-multilib --disable-static --disable-sjlj-exceptions --enable-languages=java
> 
> what version of gcc

4.5 branch: more or less 4.5.1.

> & glibc are you using?

Hmmm, dunno.  Whatever is in Fedora 12: glibc-2.11.2-1.

Andrew.

Re: Advice on compiling GCJ for ARM

[Josh Marinacci]

> 4.5 branch: more or less 4.5.1.
> 
>> & glibc are you using?
> 
> Hmmm, dunno.  Whatever is in Fedora 12: glibc-2.11.2-1.

Ah, so you are compiling against a premade glibc for your target OS. That was the part I was missing.  Last night I finally got it to work by compiling just binutils & gcc 4.5.1 w/ gmp, mpc, &  mpfr linked in.  I can now create a hello world app that runs on the real device, using static linking.  Dynamic linking still fails, though. When I copy the lib directory to the device, change LD_LIBRARY_PATH to point to it, then run the dynamically linked executable it complains that the lib elf is the wrong version.  So something is still wonky, but I'm very happy to have gotten this far.

- Josh


Blasting forth in three part harmony!

Re: Advice on compiling GCJ for ARM

[Dr Andrew John Hughes]

On 22 September 2010 09:09, Andrew Haley <aph@redhat.com> wrote:
> On 21/09/10 15:18, Josh Marinacci wrote:
>>
>> On Sep 21, 2010, at 4:55 AM, Andrew Haley wrote:
>>
>>> On 21/09/10 04:14, Josh Marinacci wrote:
>>>
>>>> I've been trying off and on for a week to build a GCJ compiler for
>>>> webOS, a Linux variant on ARM, with very little success.  On the
>>>> bright side I've started to learn more about how the GCC build
>>>> system works. :) My host machine is Mac OSX 10.6.4, Snow
>>>> Leopard. I've been able to get GCJ for Mac OSX (darwin) working
>>>> (though with a few issues), but I can't the cross compiler to even
>>>> finish compiling.
>>>
>>> Works for me.  You have to build with the right options.  My setup is
>>>
>>>  $ /home/aph/gcc/gcc-4_5-branch/configure --prefix=/home/aph/x-arm/install --target=arm-linux-gnueabi --with-sysroot=/home/aph/x-arm/rootfs-f12/ --with-headers=/home/aph/x-arm/chroot-arm/usr/include/ -disable-libssp --disable-libgomp --disable-libmudflap --disable-multilib --disable-static --disable-sjlj-exceptions --enable-languages=java
>>
>> what version of gcc
>
> 4.5 branch: more or less 4.5.1.
>
>> & glibc are you using?
>
> Hmmm, dunno.  Whatever is in Fedora 12: glibc-2.11.2-1.
>
> Andrew.
>

Running /lib/libc.so.6 will tell you :-)
-- 
Andrew :-)

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Re: Advice on compiling GCJ for ARM

[Andrew Haley]

On 22/09/10 16:05, Josh Marinacci wrote:
>> 4.5 branch: more or less 4.5.1.
>>
>>> & glibc are you using?
>>
>> Hmmm, dunno.  Whatever is in Fedora 12: glibc-2.11.2-1.
> 
> Ah, so you are compiling against a premade glibc for your target
> OS. That was the part I was missing.

That's always the easiest way to do it.  Build gcc against a system
that works, and you have a complete cross-gcc.  You can use that
cross-gcc to make your target OS; that way you have a fully working
cross-gcc from the start.

Andrew.