On Wed, Jun 12, 2013 at 7:16 AM, <mich...@cubic.org> wrote: > > "Cross-Development Toolchain: A collection of software development tools > > and > > utilities that allow you to develop software for targeted architectures." > > Is > > that different from the toolchain that bitbake builds in the beginning, > > and > > then uses to build the image? If so, what is it? > > A "cross development toolchain" is a toolchain that runs on an > architecture (cpu+os+libc) that is different from the architecture it > generates code for. That can even be a toolchain running on an IA64-Linux > machine generating object-code for an IA32-Linux machine. > > > "Following is a list of toolchain recipes..." This is followed by > > gcc-cross-initial, gcc-cross-intermediate, gcc-cross. All three of these > > things say that the toolchain runs on the host and is used to build > > software > > for the target. So why are there three of them? What are the differences > > among them? > > The gcc must be build multiple times when you bootstrap it. > For building the gcc you need to build the libc and therefor you need to > build the linux kernel headers and therefor you need the gcc. Oops. > > Thats why you first build a gcc only with c support and no libc first. > Use that to generate the kernel headers, then build the initial libc and > then another gcc with libc support and all the frontends you need > (c,c++,java,fortran,..). Why there is the gcc-cross-intermediate I am not > shure, but there will be a reason and another one can clarify that. > > > It also says that each one is a "native" package. In my > > experience, a "native" toolchain has always meant a toolchain that > > produces > > code for the same machine that the toolchain runs on, while a "cross" > > toolchain produces code for a different machine. That's obviously not > what > > "native" means in this context, so what does it mean? > > In terms of openembedded a "native" package is a package that contains > code that is intended to run on the build machine (your workstation). The > cross-compiler runs on your build-machine to produce code for your > target-machine. Thats why it is a "native" package. And there are a lot > more "native" packages than only the compiler. > > > The documentation makes frequent references to "the SDK" without ever > > defining it. I know what it means generically, but what is it in the > Yocto > > context? And why does the SDK involve yet another set of three > toolchains? > > (Oh, and why is one of them called "canadian"?) > > A canadian-cross is a term from the compiler stuff, not specific to the > Yocto Project or Poky or Openembedded. > Building a canadian-cross is the process of build a toolchain on > architecture A that runs on architecture B and produces object-code for > architecture C. An example is building a gcc on an IA32 architecture, that > will run on an ARM, producing code for an M68K. Yes, that does make sence, > if the ARM machine does not have the resources to be able to bootstrap the > compiler by itself. >
And for what it's worth, the reason it's called "Canadian" is because at the time of it's naming, Canada had 3 political parties. http://en.wikipedia.org/wiki/Cross_compiler#Canadian_Cross > Hope that made some things clear. > > Michael > _______________________________________________ > yocto mailing list > yocto@yoctoproject.org > https://lists.yoctoproject.org/listinfo/yocto >
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