On Thu, Dec 10, 2020 at 4:18 PM n952162 <n952...@web.de> wrote: > > On 12/10/20 7:18 PM, Rich Freeman wrote: > > On Thu, Dec 10, 2020 at 10:23 AM n952162 <n952...@web.de> wrote: > >> I need a new mainboard. What will happen if I boot my existing system > >> on it? > > Is the CPU going to be the same? The responses already cover the > > mainboard itself well. If the CPU could change then you need to check > > your -march in CFLAGS for compatibility (if you set it) and > > potentially rebuild anything you don't want to break. > > > > How would I do that? Would I have to set up a cross-compiler toolchain?
Nope, just remove -march from your CFLAGS (maybe change it to -mtune) and emerge -e @world (or @system if you don't care if non-system packages are broken on the new system). It is only necessary if you're switching CPUs. If you're using -march then your binaries are not guaranteed to run on ANY CPU other than the one specified, and you'd be surprised how non-backwards-compatible CPUs can be. With gcc the -march option tells the compiler that it can use any instruction it can to optimize things, including ones that are very uncommon on other CPU models. -mtune makes optimizations but the code will run on any CPU for that architecture. You can try to find a least-common-denominator CPU but it usually isn't worth the hassle. -- Rich
