Honored Contributorim trying read and write to my uart device like:
FILE *urt;
urt = fopen("/dev/UART","r+");
fprintf(urt,"data");
Honored ContributorWell, the stdio functions aren't in the small library - removing them is most of what is done to make it 'small'.
Possibly you can use the Posix open() and write() functions, but they still require a significant amount of interface 'glue' before you get to the device driver. For a small system you have to stop pretending you are writing a portable application for a large operating system and start writing code that is specific to the hardware you actually have. The means that you need to directly call the 'driver' functions, and probably change the driver internals to behave the way you need them to behave, instead of relying on 'standard' driver semantics.Honored Contributorhttp://www.alteraforum.com/forum/showthread.php?t=16836&goto=nextoldest
Is one of many threads that discuss UART access. There are some code examples included that work without open/fopen/write ... - especial on the later pages Maybe you will find there something usefulHonored Contributorwell i found an alternative method.. that is to use the the rs232 UART core for altera DE2 boards.. ftp://ftp.altera.com/up/pub/university_program_ip_cores/80/rs232.pdf its driver nicely does the job for me.. :)
but i think you're right.. when you're writing embedded programs you cant take drivers for granted.. so ill try and make my program work by directly interfacing with the device registers :)Honored ContributorIn my project I set the UART to be used for stdin and stdout and then I use the alt_printf, alt_putchar, and alt_getchar functions to read and write to the uart. My entire nios code is still under 7kb and fits in my onchip memory with plenty of room.
Honored Contributoryeah i figured thats the easiest way to do it.. but i need to use my console window and keyboard therefore i need both jtag_uart and my uart.. if i switch one of them to be my stdin,stdout im gonna need an alternative method to communicate to the other :)
thanks anyway
