On Thu, 7 Oct 2010, Andrew Stubbs wrote: > There's another issue here: using a Linux user-space compiler to build for > bare-metal is a bad plan. libgcc is built assuming that system calls and > exceptions etc. work as they do in Linux user-mode. The Linux kernel is built > with a user-space compiler for convenience, but a) the kernel is always > configured for the same hardware as the user-space, and b) it has it's own > versions of (at least some of) the libgcc routines, customized for it's own > environment.
The kernel does indeed explicitly avoid any linkage with libgcc.a. It is self contained and provide its own set of equivalent functions typically carried by libgcc.a, and explicitly _exclude_ some other functions (such as 64-bit divisions) to ensure they're never used in the kernel. > I strongly suggest you use a bare-metal compiler configured for the right > architecture(s), such as CodeSourcery's ARM EABI Lite toolchain. I think that a perfectly valid alternative is for the bare-metal target program to provide its own support library as the kernel does. So if U-Boot already comes with its own libgcc.a equivalent, then it should just be used. Nicolas _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-toolchain
