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Altera_Forum's avatar
Altera_Forum
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15 years ago

nios2 terminal output characters format problem

Hi,

I'm trying to debug a nios2 software, and i have problems with my printf outputs :

the characters are displayed in the terminal, but in a weird format..

So i then tried running the simple hello_world example :

Instead of getting in the console :

"Hello from Nios II!"

i get :

"H¢³`o;±öow.Æi¥ÕºI'¶"

And with some other random printf, i even get the error message :

"nios2-terminal: exiting due to ^D on remote"

but i didnt send any ctrl-D command...

Anyone can help me with this problem ?

Thanks

edit :

i see that the only way for me to display correct characters is to use alt_putchar function but its not very handy

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Make sure you have enough heap and stack space since they may be colliding. Also try different USB cables or ports, I remember seeing this years ago when I had my USB-Blaster hooked up to the hub inside my monitor and that LCD was spewing out more noise than a hairdryer on the line :)

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Since the smaller system using alt_putchar() instead of printf (which will pull in a LOT of libc stuff) works it does look like a memory space issue.

    (If a real async/rs232 line were involved I'd actually suggest a baud rate problem.)

    For debug, you might find it enough to write a 'putstr' function based on alt_putchar(), and a 'putint' one that converts an integer into a local buffer then sends it.

    OTOH, you could write a printf that insn't based on stdio snd libc! I've just compiled one I have for nios2 - actually snprintf() - comes out at 1725 bytes + a call to __udivsi3 (for the divide by 10 - which could be coded differently). This version is actually optimised for speed, not size, and supports all the field width stuff but no floating point.