Re: Anybody ever got an ARM Thumb-2 cross compiler to work?

[Christophe Lyon <christophe.lyon@arm.com>]

I believe these releases support the LTO plugin, but the most recent at 
the moment is 11.x. If you need GCC 12, you'll have to wait a bit :-)

Thanks,

Christophe


On 6/16/22 23:06, Gary Oblock via Gcc-help wrote:
> Chistophe,
> 
> That would work for me if it's GCC 12 based and built to support the LTO "pluggin."
> Would you know if that's the case?
> 
> Thanks,
> 
> Gary
> ________________________________
> From: Christophe Lyon <christophe.lyon.oss@gmail.com>
> Sent: Thursday, June 16, 2022 12:45 AM
> To: Gary Oblock <gary@amperecomputing.com>
> Cc: Jonathan Wakely <jwakely.gcc@gmail.com>; Gary Oblock via Gcc-help <gcc-help@gcc.gnu.org>
> Subject: Re: Anybody ever got an ARM Thumb-2 cross compiler to work?
> 
> [EXTERNAL EMAIL NOTICE: This email originated from an external sender. Please be mindful of safe email handling and proprietary information protection practices.]
> 
> Hi Gary,
> 
> Sorry, your request is not entirely clear to me either.
> IIUC what you want to achieve has been working for decades and is certainly not obsolete :-)
> 
> If you don't need to build such a toolchain, you can download pre-built binary toolchains from Arm for instance:
> https://developer.arm.com/Tools%20and%20Software/GNU%20Toolchain#Technical-Specifications
> 
> If you want to build a cross toolchain, it's not straightforward but very well supported. I think there are already plenty of documentation describing how to do that.
> 
> The important thing is to get the right target triplet when configuring your toolchain, you want something like arm-eabi or arm-linux-gnueabi, as opposed to aarch64*.
> 
> Once the build has completed, when using the compiler make sure to generate code for an architecture/cpu that actually supports Thumb-2 (via -march=XX/-mcpu=XXX), and use -mthumb, as it's generally not the default.
> 
> Christophe
> 
> 
> On Thu, Jun 16, 2022 at 9:11 AM Gary Oblock via Gcc-help <gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org>> wrote:
> Jonathan
> 
> By off the shelf, I mean not creating a new target description file. Something
> which I'm not at all experienced in (optimizations are my thing so I'm an
> amateur at creating a cross-compiler.)
> 
> I can't seem to figure out what the binutils or the gcc target is for Thumb-2.
> If you know, please let me know. I suspect that is an obsolete target
> that no longer exists for the latest binutils and GCC 12.
> 
> Thanks,
> 
> Gary
> 
> ________________________________
> From: Jonathan Wakely <jwakely.gcc@gmail.com<mailto:jwakely.gcc@gmail.com>>
> Sent: Wednesday, June 15, 2022 11:31 PM
> To: Gary Oblock <gary@amperecomputing.com<mailto:gary@amperecomputing.com>>
> Cc: Gary Oblock via Gcc-help <gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org>>
> Subject: Re: Anybody ever got an ARM Thumb-2 cross compiler to work?
> 
> [EXTERNAL EMAIL NOTICE: This email originated from an external sender. Please be mindful of safe email handling and proprietary information protection practices.]
> 
> 
> 
> On Thu, 16 Jun 2022, 00:18 Gary Oblock via Gcc-help, <gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org><mailto:gcc-help@gcc.gnu.org<mailto:gcc-help@gcc.gnu.org>>> wrote:
> The subject line says it all...
> 
> I'm beginning to think off the shelf gcc cross compilers are impossible
> to create because of binutils.
> 
> Why?
> 
> What do you mean by "off the shelf"?
> 
> At other companies we for the most part
> created custom assemblers, loaders and libraries from scratch
> when we built a gcc cross compiler.
> 
> Why can't you just build a cross binutils too?