Hello there,
I cannot seem to read from a file when using semihosting in the MCUXpresso IDE v10.2.1 with the IMXRT1050-EVKB.
I followed the step-by-step guide and successfully ran the "Hello world" example on the board. The board is connected via USB to my Windows 7 PC.
I've set the library/header type to "Newlib (semihost)" via the the quick settings. And added some fopen(), fprintf() and fscanf() routines to the example (the whole project including the changed hello_world.c is attached).
The thing the main program now should do is to open a file, write "Hello World!" to it, read the contents of the file again to strings and print it out on stdout. But, I get only garbage when reading from the file. When I examined the file, I found that the writing had worked correctly.
The program's output is:
[[MCUXpresso Semihosting Telnet console for 'evkbimxrt1050_hello_world_file LinkServer Debug' started on port 56900 @ 127.0.0.1]
+b ðÿÿÿÿÿÿÿÿ .
[Closed Telnet Session]
The string is supposed to be the string "Hello World!", as read from the file. Is this a known problem with the semihosting? Is there an update or at least a workaround? Reading from files is essential for our demo applications.
Note: With the redlib (semihost) library, even file opening does not work at all.
Unfortunately, I cannot attach the project fie because the site won't let me ("An unexpected error has occurred. Please make sure that your session did not expire while viewing this page."). So I added only the relevant content of hello_world.c at the end of this post.
Thanks for any help!
/*!
* @brief Main function
*/
int main(void)
{
char ch;
FILE *myfile;
char mystrings[2][10];
/* Init board hardware. */
BOARD_ConfigMPU();
BOARD_InitPins();
BOARD_BootClockRUN();
BOARD_InitDebugConsole();
/* Write to file */
myfile = fopen("tmp.txt", "w");
if (myfile == NULL) {
fprintf(stderr, "Could not open file for writing\n");
return 1;
}
fprintf(myfile, "hello world.\n");
fclose (myfile);
/* Read from file */
myfile = fopen("tmp.txt", "r");
if (myfile == NULL) {
fprintf(stderr, "Could not open file for reading\n");
return 1;
}
fscanf(myfile, "%s %s", mystrings[0], mystrings[1]);
fclose (myfile);
/* Print file's contents */
printf("%s %s.\n\n", mystrings[0], mystrings[1]);
while (1)
{
ch = GETCHAR();
PUTCHAR(ch);
}
}
