NIOS II hangs when switching to onchip memory

Thank you all for your suggestions.

With your input I reduced the code footprint down to 23k, which fits into the 24k of on chip memory.

However, still there's no function, the NIOS hangs when calling "alt_flash_open_dev".

I tried to reproduce this simulating the NIOS in modelsim and found out that the NIOS hangs when calling strlen from within "alt_flash_open_dev", but only if the read-only data memory is set to onchip memory.

Setting the read-only data memory to external SRAM it behaves fine in modelsim, but in reality there's still no function.

BTW: is it legal to set the read-only section to not initialízable external memory? Does the startup code handle the initialisation?