How large is your struct? Know that some of the 32K of SRAM is reserved by the BIOS, specifically if you're using the FAT filesystem.
This test program of mine compiled fine:
Code:
#class auto
#memmap xmem
typedef struct {
int a, b, c;
} typeStruct;
bbram typeStruct myStruct;
int main()
{
return 1;
}