one small querry.. when i use external SRAM in my design using nios2 for DE1 board my code wil be placed there in sram .. i want my code to be in onchip memory.. not sram.. how to do this..please help out

If you use the IDE, open the syslib properties. Here you can select where each part of your program (code, data, stack, ...) will be placed. If you use a linker script, you'll need to modify the appropriate entry in the file.

It depends on the tools you are using. If you have the old IDE you need to look into the system library properties. There you will be able to set which memory to use for different parts of your application. If you use the new development environment you need to look into the BSP settings.

If you put the code in internal memory, you may need to write your own linker script in order to get the other sections assigned to appropriate places. In the code memory is tightly coupled (which makes sense), you want to put the readonly data with the rest of the data (no point doing an avalon MM transfer into the dual port of the code memory - especially is much of your data is also in tightly coupled memory. This allows you to remove the cpu data access to the instrcution memory (unless you need it for loading the code - I don't). If you are using gcc4 there is a slight fubar! The Altera gcc4 build forces switch statement jump tables into the code section (instead of readonly data - or a section which the linker script can assign appropriately). The comments imply this was done because of missing relocation types for PIC code. But they forced it for all compilations (it would have been trivial to do this only for PIC builds). The jump table could be shortened by one instruction anyway! and even more if the jump table could be marked as 'small data' and appropriate gcc instruction patterns written - I didn't have any in my really critical code so didn't try too hard to do this!

hey replies really helped... thanks.. few more things 1)is it must to have .rodata , .rwdata , .heap in same mem location...... 2) and which is my code in .rodata and .rwdata ....... 3)if im correct .rodata is my code and .rwdata is the data wat i use for processing like inputs outputs and memory i update right? please correct me if im wrong.. and it would be of good help if you guys can provide me literature to read for such thing (and some heads up about multiprocessor design other than tutorial)

1) each section can be mapped to a different mem location 2) .rodata: read only (constant) data .rwdata: read/write data, i.e. all your program variables .text : program code For further information browse the Nios literature: http://www.altera.com/literature/lit-nio2.jsp In particular you find the information about memory sections in the Nios Software Developer's HandBook Regards

where does code resides | Altera Community

13 Replies

Altera_Forum
Honored Contributor
15 years ago
I think you missed out these letter! Please don't

the yo ad ae' ae' h ou ?
Altera_Forum
Honored Contributor
15 years ago
hey sorry prob wit my server.. so multiple same posts.. and sorry to be dumb again.. but im not finding that compiler option .. where to change or set it to optimise for size.. pls be prceise on GUI
Altera_Forum
Honored Contributor
15 years ago
In the old IDE: Project > Settings > C/C++ Build > Tool Settings > Nios II Compiler > General > Optimization Levels
In the new EDS: Project > Settings > Nios II Application Properties > Optimization Level

Forum Discussion

where does code resides

13 Replies

Recent Discussions

Ashling RISC Free IDE fails to download ELF file

Dual Port Nios V BSP error

set_output_delay explained for dummies

[Test only]How to verify Agilex 3 in radiation tolerant environment

gdb server problem when debugging