Hi, everybody.
I want to place some code, that is critical in fast onchip memory. I've read in "Nios II Software Developer's Book" from Altera's site this:
"Within your program source code, you can specify a target memory
section for a specific piece of code. To do this action in C or C++, you can
use the section attribute. The following code shows placing a variable
foo within the memory named on_chip_memory, and the function
bar()in the memory named sdram.
Use the extension .txt for code, and the extension .rodata for
read-only data or .rwdata for read-write data.
Example: Manually Assigning C Code to a Specific Memory Section
/* data should be initialized when using the section attribute */
int foo __attribute__ ((section (".on_chip_memory.rwdata"))) = 0;
void bar __attribute__ ((section (".sdram.txt"))) (void)
{
foo++;
}"
I'm using Nios II IDE, have onchip memory generated in SOPC Builder named onchip_memory_0, and I want to place my interrupt service routine in this memory. For program, read only, heap, stack, and read/write memory in system description in Nios II IDE I choose sram. I can define variable in this memory like this:
int foo __attribute__ ((section (".onchip_memory_0.rwdata"))) = 0;
,but if I try to place there function like this:
void function __attribute__ ((section (".onchip_memory_0.text"))) (void)
{
foo++;
}
compiler returns errors:
1) parse error before "(" ,and
2) size of function isn't known
What's happening? What must I do? Have I write my own linker script instead of automatically written by Nios II IDE, or something?
