import project in eclipse shows "unresovled inclusion "

hi

i download a reference design, i have to import software design because the project path changes.

firstly,i import the software in nios eclipse,

secondly, i change the settin.bsp file , change the "BspGeneratedLocatio" and the SopcDesinFile" lines

then i regenerate the bsp,

when i build the project, th eclispse tells me there are some "unresovled inlusion", such # include "alt_types.h"# include "alter_aalon_pio_regs.h"

and then lots of errors:

Symbol "PIO_IC_IRQ_BASE" could not e resolved

i check the properties for the project, in C/C++ General=>Paths and Symbols

in the Icludes tab, there are two GNU C, one is empty, and the other one include a lot of paths

can someone help me?

thanks!