Retargeting printf under SEGGER Embedded Studio

Question

Hi all, 
 I'm currently trying to get the UART example (no SoftDevice) to work under Segger Embedded Studio. What I know is, that retarget.c is used to redefine the neccesary functions for printf (stdio). 
 app_uart_get and app_uart_put work absolutely fine. However, printf is not working. Compiling the example in Embedded Studio results in the following errors: 
 storage size of '__stdout' isn't known
storage size of '__stdin' isn't known 
 Commenting the FILE __stdout and FILE __stdin lines out gets compilation running however printf doesn't work. 
 Does anyone can help me with that? 
 Thank you! 
 Martin

mcn · Accepted Answer

Thank you for your answer! 
 This is the solution: 
 
 Do not use the website, since there are minor mistakes in the code. Use this: www.segger.com/.../EmbeddedStudio_v310i_manual.pdf 
 This is the easiest way:
a) Include stdarg.h 
 
 b)
Define a function: 
 void uart_printf(const char *fmt, ...)
{
 char buf[80], *p;
 va_list ap;
 va_start(ap, fmt);
 vsnprintf(buf, sizeof(buf), fmt, ap);
 for (p = buf; *p; ++p)
 app_uart_put(*p);
 va_end(ap);
 }
 
 c) Use this function, done :) 
 Best regards

Retargeting printf under SEGGER Embedded Studio

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