Do you need an eCos HAL for your board? Zylin will be happy to write one for you, but if you have the capacity do this in-house and you want to, then you will find some useful guidelines here.

eCos does not support STL out of the box. Zylin's favored approach is to use a GCC toolchain w/libstdc++ and POSIX threads.

Same as the above, only for Nios.

If you have questions that pertain to Zylin's open source/free products, feel free to post a question to this list.