Beginners problems. i need assistance...

Before you read this: it may look like i am ranting and raving. That is not the case.

I am just frustrated after a week of problems, that's all.

All the questions i have are very simple basic questions. Things that take 1 click or 1 line of code in the IDE and C compilers from Keil or Tasking, yet turn out to be a complete nightmare in this NIOS IDE if you are starting with this tool coming from a diffrent environment ( 8051 C compiler from Keil )

I am sure that they are very easy for someone who knows this development environment. But for a starting idiot like me this is a friggin nightmare.

For the past week i have been trying to get support from Altera on my questions.

The mysupport is no good. I have now 6 open cases. None of them have been answered to my satisfaction. I have been playing ping-pong with them and ave only gotten half answers. I want to move forward.

I have serious 'beginners' problems with the nios development tools.

a simple example:

Make a new C/C++ project.

Add a file called main_program.c with the following code : void main(void) {}

Click build. The builder crashes with some cryptic error. Now what ?

Other questions i have that go unanswered :

- How do i assign a variable to a specific address. ( like the _at_ directive in Keil's C51 )

- How do i write an interrupt handler ? ( in the 8051 world this is easy just write 'interrupt x) after your function header and you are done. the linkers know what to do)

- What is the layout in memory of a progam ? I need to know exactly how a program is stored in RAM and how to put a binary file there. All the solutions given are only half solutions that either don't work or are plain wrong. Solutions like 'you need to make an SREC file' are not solutions. I need to see a step by step example. I don't know these command line tools. It took me a while to find out that this is a motorola S record and i need to use some tool called nios2-elf-objcopy to generate one. I played with the nios2-elf-objcopy a bit but can't get it to work. First it crashed because it couldnt find some DLL ( cygwin-whatever) after finding that and putting it in the same directory it still crashes.

I want a step by step example. Besides, i don't want a motorola format. i need a simple binary file or intel hex file i can load into ram. ( i have access to the nios main SRAM through an avalon master. So i can read 4 bytes from the binary file at a time and store them as 32 bit words. When all is done i bring the nios out of reset and the program should begin executing. ( hopefully ... )

I want to know what the layout of the file is. If i read the first four bytes in the binary file

these should go to the first 32 bit word ( my SRAM is 32 bit wide ) What is the byte layout ?

suppose the file looks like this

0xaa

0xbb

0xcc

0xdd

do i store DDCCBBAA into the first 32 bit word or do is store AABBCCDD into the first 32 bit word ?

On the demo program : I don't need an operating system , i dont need the jtag debugger, i dont need 'printf' ( why is the printf demo 70 kilobyte when compiled ? it should be 25 bytes ... 12 to store the string 'hello world' and a couple of instructions to send them one by one to the uart and wait for the transmit flag to clear. anyway , back tot he point)

i need nothing. The demo program i need is 20 lines of C code ( if i have such a demo i can adapt and extend it to handle the real job i want to run on the nios. i don't expect anyone to write my whole system. I have the system running on an 8051 but want to port to nios so i can do 32 bit arithmetic faster.

All i need is a simple skeleton. I can take it from there.

The program needs to react to 2 hardware interrupts, read data from some memory locations, do some simple calculations ( integer math ) perform a simple decision and write some output to some other memory locations. The compiled machine language program is maybe 30 instructions.

here is the program in pseudo code :

int a _at_ 0x00100000; // in the DPRAM

int b _at_ 0x00100004; // in the DPRAM

int c _at_ 0x00100008; // in the DPRAM

int d _at_ 0x001F0008; // a hardware IO port ( register )

int e _at_ 0x001F0000; // a hardware IO port ( combinatorial block)

void int_1_handler(void) handles interrupt 1

{

c = ((b+1) << 4) +a;

e=1;

}

void int_2_handler(void) handles interrupt 2

{

if c > 0 : c = c -1;

e=1;

}

void main (void)

{ while 1

{

if (d == 1) d = 0 else d =1;

}

}

I have the nio shardwar ealready defined in SOPc builder and it synthesizes

The nios has SRAM from 0000000 to 001FFFFF That is where the program ,stack and all other stuff needs to resides.

0x001F00008 is a hardware io port. ( there is a peripheral mapped there )

Locations 0x001000000 and the others reside in an on board dual port ram. an external system loads data into A and B and triggers either interrupt 1 or 2.

0x001F00008 is also a hardware port. (a custom peripheral. there is no 'memory' there. no flipflops are there, only an address decoder and some combinatorial logic. if a write is detected to bit 0 if that address a block of hardware is triggered that reads memory location 8 in the dual port ram to retrieve the data belonging to variable 'c'.

After posting on various forums someone explained that i can use a define construction like :

# define a (*(volatile unsigned int *) (0x00100000))

# define b (*(volatile unsigned int *) (0x00100004))

etcetera. is this correct ? Will the linker know it needs to stay away form those locations ? Will it know that it can not use those specific addresses to store anything ?

What if i map variables in the main memory ( the main SRAM ) lets say i map something like this :

# define global_q (*(volatile unsigned int *) (0x00004000))

this falls in the middle of the SRAM. will the linker know that this is no-go area and map both program and data around this specific location ?

i have a bunch of variables that need to reside at very specific locations in SRAM because they get written through an avalon master port that can stop the NIOS, change the contents of those locations and let the NIOS resume. For some other storage is use dual port ram so i don't need to stop the nios. ( the nios will be busy in another memory region at that time. that is guaranteed by the way my hardware is built. ) DMA is not an option. i wan ttht nios to do one thing while i load a part of its memory with information for the next thing.

More questions :

How can i see the compiled output as machine language ( ASM opcodes ) (The Keil compiler can show you every single line of 'c' code and the machine language created for it. I would like to see what the compiler does with the code i write.)

Is there ANYONE available who can spend half a day sitting next to me and guide me step by step on how to create a blank project with only an empty main routine and 2 interrupt handlers. I really need to 'see' how it is done.

A big thanks upfront for the brave soul who want to help me. Oh, and it doesn't need to be for free. I am located in San Jose.

desperate ...