I built the freedom-u-sdk on my ubuntu 16.04 dev machine. I cross compiled a program on the dev machine, copied the a.out to the freedom-unleashed board, ran the a.out there, got a core file, copied the core file back.
The cross-targeted gdb on the dev box doesn’t recognize the core file; gdb says (Elided):
…
This GDB was configured as “–host=x86_64-pc-linux-gnu --target=riscv64-unknown-linux-gnu”.
…
“core”: no core file handler recognizes format
freedom-u-sdk uses an old copy of riscv-gnu-toolchain that uses an old local port of gdb. I added core file support to FSF gdb over the summer and a few weeks ago I replaced the local gdb port in riscv-gnu-toolchain with the FSF gdb port. So if you git clone an up-to-date copy of riscv-gnu-toolchain this should work. But it isn’t expected to work with the toolchain in freedom-u-sdk.
freedom-u-sdk is what we use for demos. It isn’t meant to be a real linux system. If you want a real linux system, you should use debian, fedora, opensuse, openembedded/yocto, etc.