diff --git a/arch/sim/src/Makefile b/arch/sim/src/Makefile
index 542a0567470..1f65cdff48a 100644
--- a/arch/sim/src/Makefile
+++ b/arch/sim/src/Makefile
@@ -118,7 +118,7 @@ ifeq ($(CONFIG_FS_LARGEFILE),y)
 endif
 
 HOSTSRCS  = sim_hostirq.c sim_hostmemory.c sim_hostmisc.c sim_hosttime.c sim_hostuart.c
-HOSTSRCS += sim_hostfs.c
+HOSTSRCS += sim_hostfs.c sim_errno.c
 
 hostfs.h: $(TOPDIR)/include/nuttx/fs/hostfs.h
 	@echo "CP:  $<"
diff --git a/arch/sim/src/sim/CMakeLists.txt b/arch/sim/src/sim/CMakeLists.txt
index 3b3da83e189..2c90e3fad47 100644
--- a/arch/sim/src/sim/CMakeLists.txt
+++ b/arch/sim/src/sim/CMakeLists.txt
@@ -284,6 +284,8 @@ endif()
 list(APPEND HOSTSRCS sim_hostfs.c)
 list(APPEND HOST_DEFINITIONS CONFIG_NAME_MAX=${CONFIG_NAME_MAX})
 
+list(APPEND HOSTSRCS sim_errno.c)
+
 configure_file(${NUTTX_DIR}/include/nuttx/fs/hostfs.h
                ${CMAKE_CURRENT_BINARY_DIR}/hostfs.h COPYONLY)
 configure_file(${CMAKE_BINARY_DIR}/include/nuttx/config.h
diff --git a/arch/sim/src/sim/posix/sim_errno.c b/arch/sim/src/sim/posix/sim_errno.c
new file mode 100644
index 00000000000..77066082a17
--- /dev/null
+++ b/arch/sim/src/sim/posix/sim_errno.c
@@ -0,0 +1,46 @@
+/****************************************************************************
+ * arch/sim/src/sim/posix/sim_errno.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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
+ *
+ *   http://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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <errno.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int host_errno_convert(int errcode)
+{
+  return errcode;
+}
+
+int host_errno_get(void)
+{
+  return errno;
+}
+
+void host_errno_set(int errcode)
+{
+  errno = errcode;
+}
diff --git a/arch/sim/src/sim/sim_internal.h b/arch/sim/src/sim/sim_internal.h
index b3675bb79b7..da1f8d5d942 100644
--- a/arch/sim/src/sim/sim_internal.h
+++ b/arch/sim/src/sim/sim_internal.h
@@ -107,12 +107,6 @@
 #define sim_savestate(regs) sim_copyfullstate(regs, up_current_regs())
 #define sim_restorestate(regs) up_set_current_regs(regs)
 
-/* Provide a common interface, which should have different conversions
- * on different platforms.
- */
-
-#define host_errno_convert(errcode) (errcode)
-
 #define sim_saveusercontext(saveregs, ret)                      \
     do                                                          \
       {                                                         \
@@ -215,6 +209,12 @@ void sim_copyfullstate(xcpt_reg_t *dest, xcpt_reg_t *src);
 void *sim_doirq(int irq, void *regs);
 void  sim_unlock(void);
 
+/* sim_errno.c */
+
+int host_errno_convert(int errcode);
+int host_errno_get(void);
+void host_errno_set(int errcode);
+
 /* sim_hostmisc.c ***********************************************************/
 
 void host_abort(int status);
diff --git a/arch/sim/src/sim/win/sim_errno.c b/arch/sim/src/sim/win/sim_errno.c
new file mode 100644
index 00000000000..b416b5d14e1
--- /dev/null
+++ b/arch/sim/src/sim/win/sim_errno.c
@@ -0,0 +1,46 @@
+/****************************************************************************
+ * arch/sim/src/sim/win/sim_errno.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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
+ *
+ *   http://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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <errno.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int host_errno_convert(int errcode)
+{
+  return errcode;
+}
+
+int host_errno_get(void)
+{
+  return errno;
+}
+
+void host_errno_set(int errcode)
+{
+  errno = errcode;
+}