application: switch to newlib_small for printf compatibility for demo_profiling

This change ensures that the profiling middleware works correctly since it
requires printf formatters (like %02) that are not supported in newlib_nano but
are available in newlib_small, mainly for terapines toolchain.

Additional comments were added to explain why this change is necessary and document
the optimization level setting for accurate profiling results.

Signed-off-by: Huaqi Fang <578567190@qq.com>

Components/profiling/README.md

@@ -1,5 +1,7 @@
 # Profiling and Coverage For Nuclei RISC-V CPU In Nuclei Studio IDE
 
+> **Note:** The profiling middleware uses `%02` format specifier in its printf statements. Ensure your C library supports this format.
+
 Profiling and coverage analysis tools like gprof and gcov play a vital role in identifying performance bottlenecks
 and untested regions within source code, ultimately leading to improved software efficiency and quality. 
 

application/baremetal/demo_profiling/Makefile

@@ -1,7 +1,8 @@
-# Please use it in Nuclei Studio IDE not in command line
-# see https://doc.nucleisys.com/nuclei_sdk/design/app.html#demo-profiling
+# This demo is intended for use in Nuclei Studio IDE
+# For more information, visit: https://doc.nucleisys.com/nuclei_sdk/design/app.html#demo-profiling
 TARGET = demo_profiling
 
+# Enable profiling middleware for this application
 MIDDLEWARE := profiling
 
 NUCLEI_SDK_ROOT = ../../..
@@ -10,8 +11,13 @@ SRCDIRS = . src
 
 INCDIRS = . inc
 
+# Use newlib_small to ensure printf formatters (e.g., %02) work properly with profiling middleware
+# Note: newlib_nano does not support certain printf formatters used by the profiling middleware
+STDCLIB ?= newlib_small
+
 DOWNLOAD ?= sram
 
+# Optimization level set to none for accurate profiling results
 COMMON_FLAGS := -O0
 
 include $(NUCLEI_SDK_ROOT)/Build/Makefile.base

application/baremetal/demo_profiling/npk.yml

@@ -32,6 +32,8 @@ configuration:
 setconfig:
   - config: download_mode
     value: sram
+  - config: stdclib
+    value: newlib_small
 
 ## Source Code Management
 codemanage: