Hi Alan,
Not quite sure what the function is supposed to actually do given your code
fragment there.
GCC works quite well with unsigned char pointers, though gdb might be slightly
harder to use with them from the command line.
I can't say I've ever really had to debug string stuff thus far.
My string print function is simply
void uart_txs( uint8_t* s)
{
while(*s != '\0')
uart_tx(*s++);
}
Haven't had any problems with it at all.
I regularly call it as uart_txs("Hello\r\n");
If you actually have in your put_message function the whole
msg[0]++;
thing then it might cause issues. String literals are constants and shouldn't
be modified unless you really know what you're doing, and where the string
literal has been placed.
Regards,
Bevan
> Date: Thu, 16 Aug 2007 03:03:08 -0700
> From: [email protected]
> To: [email protected]
> Subject: [Mspgcc-users] passing a pointer to a function with MSP430 gcc
>
>
> Dear All,
>
> I'm trying to recompile some c code that was initially with IAR in gcc. My
> function that doesn't work, is supposed to write characters to a serial
> port.
>
> The prototype of my function to write to a serial port, is:
> void put_message( unsigned char *s);
>
> I then call this function like so:
> put_message( "TEST");
>
> If I put a breakpoint inside the put_message function and examine the value
> of *s, I get 0. I've examined the "memory map" around s in gcc, and the
> memory locations after s are also set to 0.
>
> Does gcc not like unsigned char pointers?
>
> Here's a small snippet of code where the problem occurs:
>
> #include <msp430x42x.h>
>
>
>
>
> void put_message(unsigned char *msg){
>
> msg[0]++;
>
> msg[0]++;
>
> msg[0]++;
>
> msg[0]++;
>
> }
>
>
>
>
> int main(void){
>
> int i = 0;
>
>
> unsigned char message[10];
>
>
>
>
> message[0]=1;
>
> message[1]=2;
>
> message[2]=3;
>
> message[3]=4;
>
>
> P1SEL = 0;
>
> P1DIR = P1DIR | 0x8;
>
> while (1){
>
> P1OUT = P1OUT | 0x8;
>
> for (i=0;i<1000;i++){}
>
> P1OUT = P1OUT & 0xf7;
>
> for (i=0;i<1000;i++){}
>
>
> put_message(message); //neither of these function calls produce the
> correct value in put_message
>
> put_message("test");
>
>
> }
>
> }
>
> Do you have any suggestions? Thanks in advance for your help,
>
> Regards,
>
> Alan
> --
> View this message in context:
> http://www.nabble.com/passing-a-pointer-to-a-function-with-MSP430-gcc-tf4278688.html#a12178517
> Sent from the MSP430 gcc - Users mailing list archive at Nabble.com.
>
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Splunk Inc.
> Still grepping through log files to find problems? Stop.
> Now Search log events and configuration files using AJAX and a browser.
> Download your FREE copy of Splunk now >> http://get.splunk.com/
> _______________________________________________
> Mspgcc-users mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/mspgcc-users
_________________________________________________________________
News, entertainment and everything you care about at Live.com. Get it now!
http://www.live.com/getstarted.aspx
