dear:
now i am use the segger studio of v7.3. the gnu linker is used for cortex-m33 but this is some error like "prinops.c:(.text.libc.vfprintf_l+0x5c): undefined reference to `__SEGGER_RTL_vfprintf'".
and segger linker is ok。
how to solver this problem for gnu linker ?

hi:
thank your reply.

you,re right. According to the documentation, SEGGER_RTT_printf can be used. But there,re two question。

One problem is that the current SEGGER_RTT_printf formatting output has too many restrictions (such as outputting long long), and the application is not compatible with the previous one as below.

/*********************************************************************
*
* SEGGER_RTT_printf
*
* Function description
* Stores a formatted string in SEGGER RTT control block.
* This data is read by the host.
*
* Parameters
* BufferIndex Index of "Up"-buffer to be used. (e.g. 0 for "Terminal")
* sFormat Pointer to format string, followed by the arguments for conversion
*
* Return values
* >= 0: Number of bytes which have been stored in the "Up"-buffer.
* < 0: Error
*
* Notes
* (1) Conversion specifications have following syntax:
* %[flags][FieldWidth][.Precision]ConversionSpecifier
* (2) Supported flags:
* -: Left justify within the field width
* +: Always print sign extension for signed conversions
* 0: Pad with 0 instead of spaces. Ignored when using '-'-flag or precision
* Supported conversion specifiers:
* c: Print the argument as one char
* d: Print the argument as a signed integer
* u: Print the argument as an unsigned integer
* x: Print the argument as an hexadecimal integer
* s: Print the string pointed to by the argument
* p: Print the argument as an 8-digit hexadecimal integer. (Argument shall be a pointer to void.)
*/

The second problem is that there is no sprinf function？

hi:
thanks ,i solve it.

Using Segger's own linker script will automatically link __SEGGER_RTL_vfprintf and __SEGGER_RTL_vfscanf.
But I use the linker written by GNU format which cannot automatically link __SEGGER_RTL_vfprintf and __SEGGER_RTL_vfscanf.