ARM-software · VladimirUmek · Jan 27, 2026 · Jan 26, 2026 · Jan 26, 2026
diff --git a/ARM.CMSIS-Compiler.pdsc b/ARM.CMSIS-Compiler.pdsc
@@ -15,6 +15,7 @@
   <releases>
     <release version="2.2.0-dev">
       Active Development ...
+      Add components that enable stdio retarget to UART
       AC6:
       - Corrected _sys_read return value when rt_fs_read returns with error (#62)
       IAR:
@@ -108,6 +109,11 @@
       <require condition="CORE"/>
       <require condition="CortexDevice_ITM"/>
     </condition>
+    <condition id="CORE UART_CMSIS">
+      <description>CMSIS-Compiler CORE component and CMSIS-Driver USART</description>
+      <require condition="CORE"/>
+      <require Cclass="CMSIS Driver" Cgroup="USART"/>
+    </condition>
 
     <condition id="ARMCC CORE">
       <description>ARMCC and CORE component</description>
@@ -155,6 +161,13 @@
       <require condition="CORE"/>
       <require Cclass="CMSIS" Cgroup="RTOS2"/>
     </condition>
+
+    <condition id="STDIO UART CMSIS">
+      <description>STDIO retarget to CMSIS Driver UART</description>
+      <accept Cclass="CMSIS-Compiler" Cgroup="STDERR" Csub="UART" Cvariant="CMSIS"/>
+      <accept Cclass="CMSIS-Compiler" Cgroup="STDIN"  Csub="UART" Cvariant="CMSIS"/>
+      <accept Cclass="CMSIS-Compiler" Cgroup="STDOUT" Csub="UART" Cvariant="CMSIS"/>
+    </condition>
   </conditions>
   <taxonomy>
     <description Cclass="CMSIS-Compiler" doc="documentation/html/index.html">Compiler Specific Interfaces</description>
@@ -215,28 +228,36 @@
 
   <components>
     <!-- Core -->
-    <component Cclass="CMSIS-Compiler" Cgroup="CORE" Cversion="1.1.1" condition="ARMCC CortexDevice">
+    <component Cclass="CMSIS-Compiler" Cgroup="CORE" Cversion="1.2.0" condition="ARMCC CortexDevice">
       <description>Standard C Library Retarget Core</description>
       <files>
-        <file category="sourceC" name="source/armcc/retarget_io.c"/>
+        <file category="sourceC" name="source/core/armcc/retarget_io.c"/>
+        <file category="sourceC" name="source/core/stdio_cmsis_uart.c"                                 condition="STDIO UART CMSIS"/>
+        <file category="header"  name="config/stdio_cmsis_uart_config.h" attr="config" version="1.0.0" condition="STDIO UART CMSIS"/>
       </files>
     </component>
-    <component Cclass="CMSIS-Compiler" Cgroup="CORE" Cversion="1.1.0" condition="GCC CortexDevice">
+    <component Cclass="CMSIS-Compiler" Cgroup="CORE" Cversion="1.2.0" condition="GCC CortexDevice">
       <description>Standard C Library Retarget Core</description>
       <files>
-        <file category="sourceC" name="source/gcc/retarget_syscalls.c"/>
+        <file category="sourceC" name="source/core/gcc/retarget_syscalls.c"/>
+        <file category="sourceC" name="source/core/stdio_cmsis_uart.c"                                 condition="STDIO UART CMSIS"/>
+        <file category="header"  name="config/stdio_cmsis_uart_config.h" attr="config" version="1.0.0" condition="STDIO UART CMSIS"/>
       </files>
     </component>
-    <component Cclass="CMSIS-Compiler" Cgroup="CORE" Cversion="1.1.0" condition="CLANG CortexDevice">
+    <component Cclass="CMSIS-Compiler" Cgroup="CORE" Cversion="1.2.0" condition="CLANG CortexDevice">
       <description>Standard C Library Retarget Core</description>
       <files>
-        <file category="sourceC" name="source/clang/retarget_syscalls.c"/>
+        <file category="sourceC" name="source/core/clang/retarget_syscalls.c"/>
+        <file category="sourceC" name="source/core/stdio_cmsis_uart.c"                                 condition="STDIO UART CMSIS"/>
+        <file category="header"  name="config/stdio_cmsis_uart_config.h" attr="config" version="1.0.0" condition="STDIO UART CMSIS"/>
       </files>
     </component>
-    <component Cclass="CMSIS-Compiler" Cgroup="CORE" Cversion="1.2.0" condition="IAR CortexDevice">
+    <component Cclass="CMSIS-Compiler" Cgroup="CORE" Cversion="1.3.0" condition="IAR CortexDevice">
       <description>Standard C Library Retarget Core</description>
       <files>
-        <file category="sourceC" name="source/iar/retarget_io.c"/>
+        <file category="sourceC" name="source/core/iar/retarget_io.c"/>
+        <file category="sourceC" name="source/core/stdio_cmsis_uart.c"                                 condition="STDIO UART CMSIS"/>
+        <file category="header"  name="config/stdio_cmsis_uart_config.h" attr="config" version="1.0.0" condition="STDIO UART CMSIS"/>
       </files>
     </component>
 
@@ -259,7 +280,7 @@
         #define RTE_CMSIS_Compiler_File_Interface_Breakpoint /* Compiler File Interface: Breakpoint */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/retarget_fs_bkpt.c"/>
+        <file category="sourceC" name="source/file_interface/retarget_fs_bkpt.c"/>
       </files>
     </component>
 
@@ -281,7 +302,7 @@
         #define RTE_CMSIS_Compiler_STDERR_Breakpoint     /* CMSIS-Compiler STDERR: Breakpoint */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/stderr_bkpt.c"/>
+        <file category="sourceC" name="source/stderr/stderr_bkpt.c"/>
       </files>
     </component>
     <component Cclass="CMSIS-Compiler" Cgroup="STDERR" Csub="Event Recorder" Capiversion="1.1.0" Cversion="1.1.0" condition="CORE EVR">
@@ -291,7 +312,7 @@
         #define RTE_CMSIS_Compiler_STDERR_Event_Recorder /* CMSIS-Compiler STDERR: Event Recorder */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/stderr_evr.c"/>
+        <file category="sourceC" name="source/stderr/stderr_evr.c"/>
       </files>
     </component>
     <component Cclass="CMSIS-Compiler" Cgroup="STDERR" Csub="ITM" Capiversion="1.1.0" Cversion="1.1.0" condition="CORE ITM">
@@ -301,7 +322,17 @@
         #define RTE_CMSIS_Compiler_STDERR_ITM            /* CMSIS-Compiler STDERR: ITM */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/stderr_itm.c"/>
+        <file category="sourceC" name="source/stderr/stderr_itm.c"/>
+      </files>
+    </component>
+    <component Cclass="CMSIS-Compiler" Cgroup="STDERR" Csub="UART" Cvariant="CMSIS" Capiversion="1.1.0" Cversion="1.0.0" condition="CORE UART_CMSIS">
+      <description>Redirect STDERR to a CMSIS-Driver USART</description>
+      <RTE_Components_h>
+        #define RTE_CMSIS_Compiler_STDERR                /* CMSIS-Compiler STDERR */
+        #define RTE_CMSIS_Compiler_STDERR_UART_CMSIS     /* CMSIS-Compiler STDERR: UART: CMSIS */
+      </RTE_Components_h>
+      <files>
+        <file category="header" name="config/stderr_cmsis_uart_config.h" attr="config" version="1.0.0"/>
       </files>
     </component>
 
@@ -323,7 +354,7 @@
         #define RTE_CMSIS_Compiler_STDIN_Breakpoint      /* CMSIS-Compiler STDIN: Breakpoint */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/stdin_bkpt.c"/>
+        <file category="sourceC" name="source/stdin/stdin_bkpt.c"/>
       </files>
     </component>
     <component Cclass="CMSIS-Compiler" Cgroup="STDIN" Csub="ITM" Capiversion="1.1.0" Cversion="1.1.0" condition="CORE ITM">
@@ -333,7 +364,17 @@
         #define RTE_CMSIS_Compiler_STDIN_ITM             /* CMSIS-Compiler STDIN: ITM */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/stdin_itm.c"/>
+        <file category="sourceC" name="source/stdin/stdin_itm.c"/>
+      </files>
+    </component>
+    <component Cclass="CMSIS-Compiler" Cgroup="STDIN" Csub="UART" Cvariant="CMSIS" Capiversion="1.1.0" Cversion="1.0.0" condition="CORE UART_CMSIS">
+      <description>Retrieve STDIN from a CMSIS-Driver USART</description>
+      <RTE_Components_h>
+        #define RTE_CMSIS_Compiler_STDIN                 /* CMSIS-Compiler STDIN */
+        #define RTE_CMSIS_Compiler_STDIN_UART_CMSIS      /* CMSIS-Compiler STDIN: UART: CMSIS */
+      </RTE_Components_h>
+      <files>
+        <file category="header" name="config/stdin_cmsis_uart_config.h" attr="config" version="1.0.0"/>
       </files>
     </component>
 
@@ -355,7 +396,7 @@
         #define RTE_CMSIS_Compiler_STDOUT_Breakpoint     /* CMSIS-Compiler STDOUT: Breakpoint */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/stdout_bkpt.c"/>
+        <file category="sourceC" name="source/stdout/stdout_bkpt.c"/>
       </files>
     </component>
     <component Cclass="CMSIS-Compiler" Cgroup="STDOUT" Csub="Event Recorder" Capiversion="1.1.0" Cversion="1.1.0" condition="CORE EVR">
@@ -365,7 +406,7 @@
         #define RTE_CMSIS_Compiler_STDOUT_Event_Recorder /* CMSIS-Compiler STDOUT: Event Recorder */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/stdout_evr.c"/>
+        <file category="sourceC" name="source/stdout/stdout_evr.c"/>
       </files>
     </component>
     <component Cclass="CMSIS-Compiler" Cgroup="STDOUT" Csub="ITM" Capiversion="1.1.0" Cversion="1.1.0" condition="CORE ITM">
@@ -375,7 +416,17 @@
         #define RTE_CMSIS_Compiler_STDOUT_ITM            /* CMSIS-Compiler STDOUT: ITM */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/stdout_itm.c"/>
+        <file category="sourceC" name="source/stdout/stdout_itm.c"/>
+      </files>
+    </component>
+    <component Cclass="CMSIS-Compiler" Cgroup="STDOUT" Csub="UART" Cvariant="CMSIS" Capiversion="1.1.0" Cversion="1.0.0" condition="CORE UART_CMSIS">
+      <description>Redirect STDOUT to a CMSIS-Driver USART</description>
+      <RTE_Components_h>
+        #define RTE_CMSIS_Compiler_STDOUT                /* CMSIS-Compiler STDOUT */
+        #define RTE_CMSIS_Compiler_STDOUT_UART_CMSIS     /* CMSIS-Compiler STDOUT: UART: CMSIS */
+      </RTE_Components_h>
+      <files>
+        <file category="header" name="config/stdout_cmsis_uart_config.h" attr="config" version="1.0.0"/>
       </files>
     </component>
 
@@ -397,7 +448,7 @@
         #define RTE_CMSIS_Compiler_TTY_Breakpoint        /* CMSIS-Compiler TTY: Breakpoint */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/tty_bkpt.c"/>
+        <file category="sourceC" name="source/tty/tty_bkpt.c"/>
       </files>
     </component>
     <component Cclass="CMSIS-Compiler" Cgroup="TTY" Csub="ITM" Capiversion="1.1.0" Cversion="1.1.0" condition="ARMCC CORE ITM">
@@ -407,7 +458,7 @@
         #define RTE_CMSIS_Compiler_TTY_ITM               /* CMSIS-Compiler TTY: ITM */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/tty_itm.c"/>
+        <file category="sourceC" name="source/tty/tty_itm.c"/>
       </files>
     </component>
 
@@ -443,7 +494,7 @@
         #define RTE_CMSIS_Compiler_OS_Interface_RTOS2_LIBSPACE  /* Implements per-thread static data management */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/armcc/retarget_os_rtos2.c"/>
+        <file category="sourceC" name="source/os_interface/armcc/retarget_os_rtos2.c"/>
       </files>
     </component>
     <component Cclass="CMSIS-Compiler" Cgroup="OS Interface" Csub="CMSIS-RTOS2" Capiversion="1.1.0" Cversion="2.1.0" condition="GCC CORE CMSIS-RTOS2">
@@ -455,7 +506,7 @@
         #define RTE_CMSIS_Compiler_OS_Interface_RTOS2_LOCKS     /* Implements locking routines */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/gcc/retarget_lock_rtos2.c"/>
+        <file category="sourceC" name="source/os_interface/gcc/retarget_lock_rtos2.c"/>
       </files>
     </component>
     <component Cclass="CMSIS-Compiler" Cgroup="OS Interface" Csub="CMSIS-RTOS2" Capiversion="1.0.0" Cversion="2.0.0" condition="IAR CORE CMSIS-RTOS2">
@@ -467,7 +518,7 @@
         #define RTE_CMSIS_Compiler_OS_Interface_RTOS2_LOCKS     /* Implements locking routines */
       </RTE_Components_h>
       <files>
-        <file category="sourceC" name="source/iar/retarget_os_rtos2.c"/>
+        <file category="sourceC" name="source/os_interface/iar/retarget_os_rtos2.c"/>
       </files>
     </component>
   </components>

diff --git a/config/stderr_cmsis_uart_config.h b/config/stderr_cmsis_uart_config.h
@@ -0,0 +1,59 @@
+/*---------------------------------------------------------------------------
+ * Copyright (c) 2026 Arm Limited (or its affiliates).
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * --------------------------------------------------------------------------
+ *
+ * Purpose:   Configure STDERR to CMSIS-Driver USART retarget implementation
+ * Revision:  V1.0.0
+ *
+ * --------------------------------------------------------------------------*/
+
+#ifndef STDERR_CMSIS_UART_CONFIG_H_
+#define STDERR_CMSIS_UART_CONFIG_H_
+
+//-------- <<< Use Configuration Wizard in Context Menu >>> --------------------
+//------ With VS Code: Open Preview for Configuration Wizard -------------------
+
+// <o>UART STDERR Buffer Size
+// <i> UART STDERR buffer is used to store STDERR data before sending it via UART
+// <i> Default: 0 (unbuffered)
+#ifndef STDERR_UART_BUFFER_SIZE
+#define STDERR_UART_BUFFER_SIZE         0
+#endif
+
+// <s>UART STDERR Buffer Section Name
+// <i> Specify the memory section name for UART STDERR buffer
+// <i> Default: .stderr_uart_buf
+#ifndef STDERR_UART_BUFFER_SECTION
+#define STDERR_UART_BUFFER_SECTION      ".stderr_uart_buf"
+#endif
+
+// <o>UART STDERR Buffer Alignment
+// <i> Define the STDERR buffer alignment in bytes
+// <i> Default: 32
+#ifndef STDERR_UART_BUFFER_ALIGNMENT
+#define STDERR_UART_BUFFER_ALIGNMENT    32
+#endif
+
+// <q>Convert LF to CRLF
+// <i> If enabled, LF characters are preceded by CR characters on output
+// <i> Default: 0
+#ifndef STDERR_CR_LF
+#define STDERR_CR_LF                    0
+#endif
+
+#endif /* STDERR_CMSIS_UART_CONFIG_H_ */
diff --git a/config/stdin_cmsis_uart_config.h b/config/stdin_cmsis_uart_config.h
@@ -0,0 +1,59 @@
+/*---------------------------------------------------------------------------
+ * Copyright (c) 2026 Arm Limited (or its affiliates).
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * --------------------------------------------------------------------------
+ *
+ * Purpose:   Configure STDIN to CMSIS-Driver USART retarget implementation
+ * Revision:  V1.0.0
+ *
+ * --------------------------------------------------------------------------*/
+
+#ifndef STDIN_CMSIS_UART_CONFIG_H_
+#define STDIN_CMSIS_UART_CONFIG_H_
+
+//-------- <<< Use Configuration Wizard in Context Menu >>> --------------------
+//------ With VS Code: Open Preview for Configuration Wizard -------------------
+
+// <o>UART STDIN Buffer Size
+// <i> UART STDIN buffer is used to store STDIN data received via UART
+// <i> Default: 64
+#ifndef STDIN_UART_BUFFER_SIZE
+#define STDIN_UART_BUFFER_SIZE          64
+#endif
+
+// <s>UART STDIN Buffer Section Name
+// <i> Specify the memory section name for UART STDIN buffer
+// <i> Default: .stdin_uart_buf
+#ifndef STDIN_UART_BUFFER_SECTION
+#define STDIN_UART_BUFFER_SECTION       ".stdin_uart_buf"
+#endif
+
+// <o>UART STDIN Buffer Alignment
+// <i> Define the STDIN buffer alignment in bytes
+// <i> Default: 32
+#ifndef STDIN_UART_BUFFER_ALIGNMENT
+#define STDIN_UART_BUFFER_ALIGNMENT     32
+#endif
+
+// <q>Echo Input Characters
+// <i> If enabled, received characters are echoed to STDOUT
+// <i> Default: 0
+#ifndef STDIN_ECHO
+#define STDIN_ECHO                      0
+#endif
+
+#endif /* STDIN_CMSIS_UART_CONFIG_H_ */