diff --git a/components/esp_driver_uart/src/uart_vfs.c b/components/esp_driver_uart/src/uart_vfs.c
index fa9221f2a58..69fef254ed5 100644
--- a/components/esp_driver_uart/src/uart_vfs.c
+++ b/components/esp_driver_uart/src/uart_vfs.c
@@ -588,7 +588,6 @@ static esp_err_t uart_end_select(void *end_select_args)
             if (s_uart_select_count[i] == 0) {
                 uart_set_select_notif_callback(i, NULL);
             }
-            break;
         }
     }
     portEXIT_CRITICAL(uart_get_selectlock());
diff --git a/components/esp_libc/src/picolibc/picolibc_init.c b/components/esp_libc/src/picolibc/picolibc_init.c
index 0756627ef42..2e6731b5bf3 100644
--- a/components/esp_libc/src/picolibc/picolibc_init.c
+++ b/components/esp_libc/src/picolibc/picolibc_init.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2024-2025 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -138,32 +138,38 @@ void esp_reent_cleanup(void)
  * Initialize stdin, stdout, and stderr using static memory allocation.
  * Creating them with fopen() would call malloc() internally.
  */
-static char write_buf[BUFSIZ];
-static char read_buf[BUFSIZ];
+static char in_buf[BUFSIZ];
+static char out_buf[BUFSIZ];
+static char err_buf[BUFSIZ];
 
-static struct __file_bufio __stdin = FDEV_SETUP_BUFIO(0, read_buf, BUFSIZ, read, write, lseek, close, __SRD, 0);
-static struct __file_bufio __stdout = FDEV_SETUP_BUFIO(1, write_buf, BUFSIZ, read, write, lseek, close, __SWR, __BLBF);
+static struct __file_bufio __stdin = FDEV_SETUP_BUFIO(0, in_buf, BUFSIZ, read, write, lseek, close, __SRD, 0);
+static struct __file_bufio __stdout = FDEV_SETUP_BUFIO(1, out_buf, BUFSIZ, read, write, lseek, close, __SWR, __BLBF);
+static struct __file_bufio __stderr = FDEV_SETUP_BUFIO(2, err_buf, BUFSIZ, read, write, lseek, close, __SWR, __BLBF);
 
 FILE *stdin = &__stdin.xfile.cfile.file;
 FILE *stdout = &__stdout.xfile.cfile.file;
-FILE *stderr = &__stdout.xfile.cfile.file;
+FILE *stderr = &__stderr.xfile.cfile.file;
 
 #if CONFIG_LIBC_PICOLIBC_NEWLIB_COMPATIBILITY
 __thread FILE* tls_stdin = &__stdin.xfile.cfile.file;
 __thread FILE* tls_stdout = &__stdout.xfile.cfile.file;
-__thread FILE* tls_stderr = &__stdout.xfile.cfile.file;
+__thread FILE* tls_stderr = &__stderr.xfile.cfile.file;
 #endif
 
 #if CONFIG_VFS_SUPPORT_IO
 void esp_libc_init_global_stdio(const char *stdio_dev)
 {
     int stdin_fd = open(stdio_dev, O_RDONLY);
-    assert(stdin_fd > 0);
+    assert(stdin_fd >= 0); // Should be 0
     __stdin.ptr = (void *)(intptr_t)(stdin_fd);
 
     int stdout_fd = open(stdio_dev, O_WRONLY);
-    assert(stdout_fd > 0);
+    assert(stdout_fd >= 0); // Should be 1
     __stdout.ptr = (void *)(intptr_t)(stdout_fd);
+
+    int stderr_fd = open(stdio_dev, O_WRONLY);
+    assert(stderr_fd >= 0); // Should be 2
+    __stderr.ptr = (void *)(intptr_t)(stderr_fd);
 }
 #else  /* CONFIG_VFS_SUPPORT_IO */
 void esp_libc_init_global_stdio(void)
diff --git a/components/esp_stdio/CMakeLists.txt b/components/esp_stdio/CMakeLists.txt
index f4253624659..e3d15f06693 100644
--- a/components/esp_stdio/CMakeLists.txt
+++ b/components/esp_stdio/CMakeLists.txt
@@ -7,7 +7,6 @@ if(non_os_build)
     idf_component_register()
     return()
 endif()
-
 set(srcs)
 set(includes)
 
@@ -18,10 +17,13 @@ if(${target} STREQUAL "linux")
                          "linux/include")
 else()
     list(APPEND srcs "stdio_port.c"
-                     "stdio_vfs.c"
                      "stdio_simple.c"
                      "stdio_syscalls_simple.c")
     list(APPEND includes "include")
+
+    if(CONFIG_VFS_SUPPORT_IO)
+        list(APPEND srcs "stdio_vfs.c")
+    endif()
 endif()
 
 idf_component_register(SRCS ${srcs}
diff --git a/components/esp_stdio/Kconfig b/components/esp_stdio/Kconfig
index a103ba0c526..3083d0f740d 100644
--- a/components/esp_stdio/Kconfig
+++ b/components/esp_stdio/Kconfig
@@ -185,4 +185,12 @@ menu "ESP-STDIO"
             If enabled, esp_rom_printf and ESP_EARLY_LOG output will also be sent over USB CDC.
             Disabling this option saves about 1kB or RAM.
 
+    config ESP_STDIO_MAX_VFS_ENTRIES
+        int "Maximum number of registerable VFS sinks"
+        depends on VFS_SUPPORT_IO
+        range 1 10
+        default 2
+        help
+            Maximum number of filesystems that can be registered as sinks for console output.
+
 endmenu
diff --git a/components/esp_stdio/stdio_vfs.c b/components/esp_stdio/stdio_vfs.c
index 28fd6487582..fb0ce9efb56 100644
--- a/components/esp_stdio/stdio_vfs.c
+++ b/components/esp_stdio/stdio_vfs.c
@@ -5,10 +5,15 @@
  */
 
 #include "sdkconfig.h"
+#include <assert.h>
+#include <stdbool.h>
 #include <fcntl.h>
+#include <string.h>
 #include "esp_err.h"
+#include "esp_log.h"
 #include "esp_rom_sys.h"
 #include "esp_stdio.h"
+#include "esp_vfs.h"
 #include <sys/errno.h>
 
 #if CONFIG_VFS_SUPPORT_IO
@@ -30,6 +35,8 @@
 
 #include "esp_private/startup_internal.h"
 #include "esp_private/nullfs.h"
+#include <sys/lock.h>
+#endif
 
 #define STRINGIFY(s) STRINGIFY2(s)
 #define STRINGIFY2(s) #s
@@ -42,135 +49,233 @@
  * while the secondary is only used for output.
  */
 
+#if CONFIG_VFS_SUPPORT_IO
+
 typedef struct {
-    int fd_primary;
-    int fd_secondary;
-} vfs_console_context_t;
+    const esp_vfs_fs_ops_t *ops;  /* NULL = slot is free */
+    void *vfs_ctx;
+    const char *path;
+    int fd;  /* -1 if not opened (used by auxiliaries) */
+} mux_entry_t;
 
-// Secondary register part.
-#if CONFIG_ESP_CONSOLE_SECONDARY_USB_SERIAL_JTAG
-const static esp_vfs_fs_ops_t *secondary_vfs = NULL;
-#endif // Secondary part
+/* Primary backend (all ops forwarded except open + write + fsync) */
+static mux_entry_t s_primary = { .fd = -1 };
 
-const static esp_vfs_fs_ops_t *primary_vfs = NULL;
+/* Auxiliary sinks (write-only fan-out) */
+#define STDIO_MAX_AUXILIARY (CONFIG_ESP_STDIO_MAX_VFS_ENTRIES - 1)
+static mux_entry_t s_auxiliary[STDIO_MAX_AUXILIARY] = { [0 ... STDIO_MAX_AUXILIARY - 1] = { .fd = -1 } };
+static int s_open_count = 0;
+static _lock_t s_lock;
 
-static vfs_console_context_t vfs_console = {0};
+static const char *TAG = "esp_stdio";
 
-static size_t s_open_count = 0;
+#ifdef CONFIG_VFS_SUPPORT_TERMIOS
+static const mux_entry_t *get_primary_termios_entry(int fd, const esp_vfs_termios_ops_t **out_ops)
+{
+    const mux_entry_t *entry = &s_primary;
+    assert(entry);
+
+    const esp_vfs_termios_ops_t *termios = entry->ops->termios;
+    if (!termios) {
+        errno = ENOSYS;
+        return NULL;
+    }
+
+    if (out_ops) {
+        *out_ops = termios;
+    }
+
+    return entry;
+}
+#endif // CONFIG_VFS_SUPPORT_TERMIOS
+
+static esp_err_t __attribute__((unused)) register_auxiliary(const esp_vfs_fs_ops_t *ops, void *ctx, const char *path)
+{
+    if (!ops || !path || !ops->write_p) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    _lock_acquire(&s_lock);
+    for (size_t i = 0; i < STDIO_MAX_AUXILIARY; i++) {
+        if (s_auxiliary[i].ops == NULL) {
+            s_auxiliary[i] = (mux_entry_t) {
+                .ops = ops,
+                .vfs_ctx = ctx,
+                .path = path,
+                .fd = -1,
+            };
+            _lock_release(&s_lock);
+            return ESP_OK;
+        }
+    }
+    _lock_release(&s_lock);
+    ESP_EARLY_LOGE(TAG, "Too many auxiliary sinks");
+    return ESP_ERR_NO_MEM;
+}
 
 int console_open(__attribute__((unused)) void *ctx, const char * path, int flags, int mode)
 {
-    if (s_open_count > 0) {
-        // Underlying fd is already open, so just increment the open count
-        // and return the same fd
-
-        s_open_count++;
-        return 0;
+    (void)path;
+    const mux_entry_t *entry = &s_primary;
+    if (!entry->ops || !entry->ops->open_p) {
+        errno = ENOSYS;
+        return -1;
     }
 
-// Primary port open
-#if CONFIG_ESP_CONSOLE_UART
-    vfs_console.fd_primary = open("/dev/uart/"STRINGIFY(CONFIG_ESP_CONSOLE_UART_NUM), flags, mode);
-#elif CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG
-    vfs_console.fd_primary = open("/dev/usbserjtag", flags, mode);
-#elif CONFIG_ESP_CONSOLE_USB_CDC
-    vfs_console.fd_primary = open("/dev/cdcacm", flags, mode);
-#else
-    vfs_console.fd_primary = open("/dev/null", flags, mode);
-#endif
-
-// Secondary port open
-#if CONFIG_ESP_CONSOLE_SECONDARY_USB_SERIAL_JTAG
-    vfs_console.fd_secondary = open("/dev/secondary", flags, mode);
-#endif
+    int local_fd = entry->ops->open_p(entry->vfs_ctx, entry->path, flags, mode);
+    if (local_fd < 0) {
+        return -1;
+    }
 
+    /* Lazily open auxiliaries on first console open */
+    _lock_acquire(&s_lock);
+    if (s_open_count == 0) {
+        for (size_t i = 0; i < STDIO_MAX_AUXILIARY; i++) {
+            mux_entry_t *aux = &s_auxiliary[i];
+            if (aux->ops && aux->ops->open_p && aux->fd < 0) {
+                aux->fd = aux->ops->open_p(aux->vfs_ctx, aux->path, O_WRONLY, 0);
+            }
+        }
+    }
     s_open_count++;
+    _lock_release(&s_lock);
+
+    return local_fd;
+}
+
+int console_close(__attribute__((unused)) void *ctx, int fd)
+{
+    const mux_entry_t *entry = &s_primary;
+    if (!entry->ops || !entry->ops->close_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+
+    int ret = entry->ops->close_p(entry->vfs_ctx, fd);
+    if (ret != 0) {
+        return ret;
+    }
+
+    /* Close auxiliaries when last console fd is closed */
+    _lock_acquire(&s_lock);
+    if (s_open_count > 0) {
+        s_open_count--;
+    }
+    if (s_open_count == 0) {
+        for (size_t i = 0; i < STDIO_MAX_AUXILIARY; i++) {
+            mux_entry_t *aux = &s_auxiliary[i];
+            if (aux->ops && aux->ops->close_p && aux->fd >= 0) {
+                aux->ops->close_p(aux->vfs_ctx, aux->fd);
+                aux->fd = -1;
+            }
+        }
+    }
+    _lock_release(&s_lock);
+
     return 0;
 }
 
 ssize_t console_write(__attribute__((unused)) void *ctx, int fd, const void *data, size_t size)
 {
-    write(vfs_console.fd_primary, data, size);
-#if CONFIG_ESP_CONSOLE_SECONDARY_USB_SERIAL_JTAG
-    write(vfs_console.fd_secondary, data, size);
-#endif
-    return size;
+    const mux_entry_t *primary = &s_primary;
+    ssize_t ret_val = primary->ops->write_p(primary->vfs_ctx, fd, data, size);
+
+    _lock_acquire(&s_lock);
+    for (size_t i = 0; i < STDIO_MAX_AUXILIARY; i++) {
+        const mux_entry_t *entry = &s_auxiliary[i];
+        if (entry->ops && entry->ops->write_p && entry->fd >= 0) {
+            (void) entry->ops->write_p(entry->vfs_ctx, entry->fd, data, size);
+        }
+    }
+    _lock_release(&s_lock);
+
+    return ret_val;
 }
 
 int console_fstat(__attribute__((unused)) void *ctx, int fd, struct stat * st)
 {
-    return fstat(vfs_console.fd_primary, st);
-}
-
-int console_close(__attribute__((unused)) void *ctx, int fd)
-{
-    if (s_open_count == 0) {
-        errno = EBADF;
+    const mux_entry_t *entry = &s_primary;
+    if (!entry->ops->fstat_p) {
+        errno = ENOSYS;
         return -1;
     }
-
-    s_open_count--;
-
-    // We don't actually close the underlying fd until the open count reaches 0
-    if (s_open_count > 0) {
-        return 0;
-    }
-
-    // All function calls are to primary, except from write and close, which will be forwarded to both primary and secondary.
-    close(vfs_console.fd_primary);
-#if CONFIG_ESP_CONSOLE_SECONDARY_USB_SERIAL_JTAG
-    close(vfs_console.fd_secondary);
-#endif
-    return 0;
+    return entry->ops->fstat_p(entry->vfs_ctx, fd, st);
 }
 
 ssize_t console_read(__attribute__((unused)) void *ctx, int fd, void * dst, size_t size)
 {
-    return read(vfs_console.fd_primary, dst, size);
+    const mux_entry_t *entry = &s_primary;
+    if (!entry->ops->read_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+    return entry->ops->read_p(entry->vfs_ctx, fd, dst, size);
 }
 
 int console_fcntl(__attribute__((unused)) void *ctx, int fd, int cmd, int arg)
 {
-    return fcntl(vfs_console.fd_primary, cmd, arg);
+    const mux_entry_t *entry = &s_primary;
+    if (!entry->ops->fcntl_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+    return entry->ops->fcntl_p(entry->vfs_ctx, fd, cmd, arg);
 }
 
 int console_fsync(__attribute__((unused)) void *ctx, int fd)
 {
-    const int ret_val = fsync(vfs_console.fd_primary);
-#if CONFIG_ESP_CONSOLE_SECONDARY_USB_SERIAL_JTAG
-    (void)fsync(vfs_console.fd_secondary);
-#endif
+    const mux_entry_t *primary = &s_primary;
+    if (!primary->ops->fsync_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+
+    int ret_val = primary->ops->fsync_p(primary->vfs_ctx, fd);
+
+    _lock_acquire(&s_lock);
+    for (size_t i = 0; i < STDIO_MAX_AUXILIARY; i++) {
+        const mux_entry_t *entry = &s_auxiliary[i];
+        if (entry->ops && entry->ops->fsync_p && entry->fd >= 0) {
+            (void) entry->ops->fsync_p(entry->vfs_ctx, entry->fd);
+        }
+    }
+    _lock_release(&s_lock);
+
     return ret_val;
 }
 
 #ifdef CONFIG_VFS_SUPPORT_DIR
 int console_access(__attribute__((unused)) void *ctx, const char *path, int amode)
 {
-    // currently only UART support DIR.
-    return access("/dev/uart/"STRINGIFY(CONFIG_ESP_CONSOLE_UART_NUM), amode);
+    const mux_entry_t *entry = &s_primary;
+    assert(entry);
+    if (!entry->ops->dir || !entry->ops->dir->access_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+    (void) path;
+    return entry->ops->dir->access_p(entry->vfs_ctx, entry->path, amode);
 }
 #endif // CONFIG_VFS_SUPPORT_DIR
 
 #ifdef CONFIG_VFS_SUPPORT_SELECT
+
 static esp_err_t console_start_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
                                       esp_vfs_select_sem_t select_sem, void **end_select_args)
 {
-    // start_select is not guaranteed be implemented even though CONFIG_VFS_SUPPORT_SELECT is enabled in sdkconfig
-    if (primary_vfs->select->start_select) {
-        return primary_vfs->select->start_select(nfds, readfds, writefds, exceptfds, select_sem, end_select_args);
+    const mux_entry_t *entry = &s_primary;
+    if (!entry->ops || !entry->ops->select || !entry->ops->select->start_select) {
+        return ESP_ERR_NOT_SUPPORTED;
     }
-
-    return ESP_ERR_NOT_SUPPORTED;
+    return entry->ops->select->start_select(nfds, readfds, writefds, exceptfds, select_sem, end_select_args);
 }
 
-esp_err_t console_end_select(void *end_select_args)
+static esp_err_t console_end_select(void *end_select_args)
 {
-    // end_select is not guaranteed be implemented even though CONFIG_VFS_SUPPORT_SELECT is enabled in sdkconfig
-    if (primary_vfs->select->end_select) {
-        return primary_vfs->select->end_select(end_select_args);
+    const mux_entry_t *entry = &s_primary;
+    if (!entry->ops || !entry->ops->select || !entry->ops->select->end_select) {
+        return ESP_ERR_NOT_SUPPORTED;
     }
-
-    return ESP_ERR_NOT_SUPPORTED;
+    return entry->ops->select->end_select(end_select_args);
 }
 
 #endif // CONFIG_VFS_SUPPORT_SELECT
@@ -179,22 +284,58 @@ esp_err_t console_end_select(void *end_select_args)
 
 int console_tcsetattr(__attribute__((unused)) void *ctx, int fd, int optional_actions, const struct termios *p)
 {
-    return tcsetattr(vfs_console.fd_primary, optional_actions, p);
+    const esp_vfs_termios_ops_t *termios = NULL;
+    const mux_entry_t *entry = get_primary_termios_entry(fd, &termios);
+    if (!entry) {
+        return -1;
+    }
+    if (!termios->tcsetattr_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+    return entry->ops->termios->tcsetattr_p(entry->vfs_ctx, fd, optional_actions, p);
 }
 
 int console_tcgetattr(__attribute__((unused)) void *ctx, int fd, struct termios *p)
 {
-    return tcgetattr(vfs_console.fd_primary, p);
+    const esp_vfs_termios_ops_t *termios = NULL;
+    const mux_entry_t *entry = get_primary_termios_entry(fd, &termios);
+    if (!entry) {
+        return -1;
+    }
+    if (!termios->tcgetattr_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+    return entry->ops->termios->tcgetattr_p(entry->vfs_ctx, fd, p);
 }
 
 int console_tcdrain(__attribute__((unused)) void *ctx, int fd)
 {
-    return tcdrain(vfs_console.fd_primary);
+    const esp_vfs_termios_ops_t *termios = NULL;
+    const mux_entry_t *entry = get_primary_termios_entry(fd, &termios);
+    if (!entry) {
+        return -1;
+    }
+    if (!termios->tcdrain_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+    return entry->ops->termios->tcdrain_p(entry->vfs_ctx, fd);
 }
 
 int console_tcflush(__attribute__((unused)) void *ctx, int fd, int select)
 {
-    return tcflush(vfs_console.fd_primary, select);
+    const esp_vfs_termios_ops_t *termios = NULL;
+    const mux_entry_t *entry = get_primary_termios_entry(fd, &termios);
+    if (!entry) {
+        return -1;
+    }
+    if (!termios->tcflush_p) {
+        errno = ENOSYS;
+        return -1;
+    }
+    return entry->ops->termios->tcflush_p(entry->vfs_ctx, fd, select);
 }
 #endif // CONFIG_VFS_SUPPORT_TERMIOS
 
@@ -242,31 +383,55 @@ static const esp_vfs_fs_ops_t s_vfs_console = {
 #endif // CONFIG_VFS_SUPPORT_TERMIOS
 };
 
-static esp_err_t esp_vfs_dev_console_register(void)
-{
-    return esp_vfs_register_fs(ESP_VFS_DEV_CONSOLE, &s_vfs_console, ESP_VFS_FLAG_STATIC | ESP_VFS_FLAG_CONTEXT_PTR, NULL);
-}
-
 esp_err_t esp_stdio_register(void)
 {
-    esp_err_t err = ESP_OK;
+    _lock_init(&s_lock);
+
 // Primary vfs part.
 #if CONFIG_ESP_CONSOLE_UART
-    primary_vfs = esp_vfs_uart_get_vfs();
+    s_primary = (mux_entry_t) {
+        .ops = esp_vfs_uart_get_vfs(),
+        .vfs_ctx = NULL,
+        .path = "/" STRINGIFY(CONFIG_ESP_CONSOLE_UART_NUM),
+        .fd = -1,
+    };
 #elif CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG
-    primary_vfs = esp_vfs_usb_serial_jtag_get_vfs();
+    s_primary = (mux_entry_t) {
+        .ops = esp_vfs_usb_serial_jtag_get_vfs(),
+        .vfs_ctx = NULL,
+        .path = "/",
+        .fd = -1,
+    };
 #elif CONFIG_ESP_CONSOLE_USB_CDC
-    primary_vfs = esp_vfs_cdcacm_get_vfs();
+    s_primary = (mux_entry_t) {
+        .ops = esp_vfs_cdcacm_get_vfs(),
+        .vfs_ctx = NULL,
+        .path = "/",
+        .fd = -1,
+    };
 #else
-    primary_vfs = esp_vfs_null_get_vfs();
+    s_primary = (mux_entry_t) {
+        .ops = esp_vfs_null_get_vfs(),
+        .vfs_ctx = NULL,
+        .path = "/",
+        .fd = -1,
+    };
 #endif
 
-// Secondary vfs part.
+    if (!s_primary.ops) {
+        ESP_EARLY_LOGE(TAG, "No primary console backend available");
+        return ESP_FAIL;
+    }
+
+// Auxiliary sinks (write-only fan-out).
 #if CONFIG_ESP_CONSOLE_SECONDARY_USB_SERIAL_JTAG
-    secondary_vfs = esp_vfs_usb_serial_jtag_get_vfs();
+    esp_err_t err = register_auxiliary(esp_vfs_usb_serial_jtag_get_vfs(), NULL, "/");
+    if (err != ESP_OK) {
+        return err;
+    }
 #endif
-    err = esp_vfs_dev_console_register();
-    return err;
+
+    return esp_vfs_register_fs(ESP_VFS_DEV_CONSOLE, &s_vfs_console, ESP_VFS_FLAG_STATIC | ESP_VFS_FLAG_CONTEXT_PTR, NULL);
 }
 
 ESP_SYSTEM_INIT_FN(init_vfs_console, CORE, BIT(0), 119)
diff --git a/components/esp_stdio/test_apps/stdio/main/test_app_main.c b/components/esp_stdio/test_apps/stdio/main/test_app_main.c
index 8a8663867b6..b860be7f343 100644
--- a/components/esp_stdio/test_apps/stdio/main/test_app_main.c
+++ b/components/esp_stdio/test_apps/stdio/main/test_app_main.c
@@ -1,11 +1,12 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 #include <stdio.h>
 #include <assert.h>
 #include <string.h>
+#include <errno.h>
 #include "sdkconfig.h"
 
 #include "esp_rom_serial_output.h"
@@ -18,6 +19,7 @@
 
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/select.h>
 
 #if CONFIG_ESP_CONSOLE_NONE
 /* Set up UART on UART_0 (console) to be able to
@@ -50,6 +52,9 @@ static void console_none_print(void)
 #endif
 
 #if CONFIG_VFS_SUPPORT_IO
+#define ESP_STDIO_RUN_OPEN_CLOSE_CHECK 1
+
+#if ESP_STDIO_RUN_OPEN_CLOSE_CHECK
 static void console_open_close_check(void)
 {
     printf("Opening /dev/console\n");
@@ -65,6 +70,79 @@ static void console_open_close_check(void)
 
     printf("This should be printed to stdout\n");
 }
+#endif
+
+static void stdio_fd_mode_behavior_check(void)
+{
+    printf("STDIO_TEST:MODE=FORWARDING\n");
+
+    int fd0 = open("/dev/console", O_RDWR);
+    assert(fd0 >= 0);
+
+    int fd1 = open("/dev/console", O_RDWR);
+    assert(fd1 >= 0);
+    assert(fd0 != fd1);
+    printf("STDIO_TEST:UNIQUE_FDS_OK\n");
+
+    const char *msg = "STDIO_TEST:WRITE_OK\n";
+    ssize_t wr = write(fd0, msg, strlen(msg));
+    assert(wr == (ssize_t) strlen(msg));
+
+    assert(fsync(fd0) == 0);
+    printf("STDIO_TEST:FSYNC_OK\n");
+
+    assert(close(fd0) == 0);
+    assert(close(fd1) == 0);
+    printf("STDIO_TEST:CLOSE_OK\n");
+}
+
+static void stdio_fd_init_check(void)
+{
+    int in_fd = fileno(stdin);
+    int out_fd = fileno(stdout);
+    int err_fd = fileno(stderr);
+
+    assert(in_fd == 0);
+    assert(out_fd == 1);
+    assert(err_fd == 2);
+
+    printf("STDIO_TEST:FD_INIT:IN=%d,OUT=%d,ERR=%d\n", in_fd, out_fd, err_fd);
+    fprintf(stdout, "STDIO_TEST:STREAM:STDOUT\n");
+    fflush(stdout);
+    fprintf(stderr, "STDIO_TEST:STREAM:STDERR\n");
+    fflush(stderr);
+}
+
+#if CONFIG_VFS_SUPPORT_SELECT && CONFIG_ESP_CONSOLE_UART
+static void stdio_select_fd_mapping_check(void)
+{
+    bool driver_installed_here = false;
+    esp_err_t err = uart_driver_install(CONFIG_ESP_CONSOLE_UART_NUM, 256, 0, 0, NULL, 0);
+    if (err == ESP_OK) {
+        driver_installed_here = true;
+    } else {
+        assert(err == ESP_ERR_INVALID_STATE);
+    }
+
+    fd_set writefds;
+    FD_ZERO(&writefds);
+    FD_SET(fileno(stdout), &writefds);
+    FD_SET(fileno(stderr), &writefds);
+
+    struct timeval tv = {
+        .tv_sec = 0,
+        .tv_usec = 0,
+    };
+
+    errno = 0;
+    int ret = select(fileno(stderr) + 1, NULL, &writefds, NULL, &tv);
+    assert(ret >= 0);
+    if (driver_installed_here) {
+        assert(uart_driver_delete(CONFIG_ESP_CONSOLE_UART_NUM) == ESP_OK);
+    }
+    printf("STDIO_TEST:SELECT:LOGICAL_FD_MAP_OK\n");
+}
+#endif
 #endif // CONFIG_VFS_SUPPORT_IO
 
 void app_main(void)
@@ -80,6 +158,11 @@ void app_main(void)
     assert(fd > 2 && "Incorrect file descriptor returned, stdin, stdout, stderr were not correctly assigned");
 
     close(fd);
+
+    stdio_fd_init_check();
+#if CONFIG_VFS_SUPPORT_SELECT && CONFIG_ESP_CONSOLE_UART
+    stdio_select_fd_mapping_check();
+#endif
 #endif // CONFIG_VFS_SUPPORT_IO
 
 #if CONFIG_ESP_CONSOLE_NONE
@@ -87,7 +170,12 @@ void app_main(void)
 #endif // CONFIG_ESP_CONSOLE_NONE
 
 #if CONFIG_VFS_SUPPORT_IO
+#if ESP_STDIO_RUN_OPEN_CLOSE_CHECK
     console_open_close_check();
+#else
+    printf("STDIO_TEST:SKIP:OPEN_CLOSE_CHECK\n");
+#endif
+    stdio_fd_mode_behavior_check();
 #endif // CONFIG_VFS_SUPPORT_IO
 
 }
diff --git a/components/esp_stdio/test_apps/stdio/pytest_esp_stdio_tests.py b/components/esp_stdio/test_apps/stdio/pytest_esp_stdio_tests.py
index 953deadccbd..29692865aa2 100644
--- a/components/esp_stdio/test_apps/stdio/pytest_esp_stdio_tests.py
+++ b/components/esp_stdio/test_apps/stdio/pytest_esp_stdio_tests.py
@@ -1,5 +1,9 @@
 # SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: CC0-1.0
+#
+# HW runs: use --embedded-services esp,idf (not idf alone) so serial is attached.
+# See README.md in this directory for QEMU vs hardware commands and common failures.
+#
 import pexpect
 import pytest
 from pytest_embedded import Dut
@@ -7,6 +11,11 @@ from pytest_embedded_idf.utils import idf_parametrize
 from pytest_embedded_idf.utils import soc_filtered_targets
 
 
+def _expect_app_main_banner(dut: Dut) -> None:
+    """Sync to the latest app boot (avoids matching a stale 'Hello World' left in the serial buffer)."""
+    dut.expect('Calling app_main()')
+
+
 def not_expect(dut: Dut, output_regex: str) -> None:
     try:
         dut.expect(output_regex, timeout=5)
@@ -34,7 +43,11 @@ def test_esp_system_stdio_no_output_uart(dut: Dut) -> None:
 @pytest.mark.temp_skip_ci(targets=['esp32h4'], reason='lack of runner # TODO: IDFCI-10703')
 def test_esp_system_stdio_only_serial_jtag(dut: Dut) -> None:
     dut.expect('2nd stage bootloader')
+    _expect_app_main_banner(dut)
     dut.expect('Hello World')
+    dut.expect('STDIO_TEST:FD_INIT:IN=0,OUT=1,ERR=2')
+    dut.expect('STDIO_TEST:STREAM:STDOUT')
+    dut.expect('STDIO_TEST:STREAM:STDERR')
     dut.expect('Opening /dev/console')
     dut.expect('This should be printed to stdout')
     dut.expect('Closing /dev/console')
@@ -50,6 +63,7 @@ def test_esp_system_stdio_only_serial_jtag(dut: Dut) -> None:
 @pytest.mark.temp_skip_ci(targets=['esp32h4'], reason='lack of runner # TODO: IDFCI-10703')
 def test_esp_system_stdio_only_serial_jtag_no_vfs(dut: Dut) -> None:
     dut.expect('2nd stage bootloader')
+    _expect_app_main_banner(dut)
     dut.expect('Hello World')
 
 
@@ -62,6 +76,7 @@ def test_esp_system_stdio_only_serial_jtag_no_vfs(dut: Dut) -> None:
 @pytest.mark.temp_skip_ci(targets=['esp32h4'], reason='lack of runner # TODO: IDFCI-10703')
 def test_esp_system_stdio_secondary_serial_jtag(dut: Dut) -> None:
     dut.expect('2nd stage bootloader')
+    _expect_app_main_banner(dut)
     dut.expect('Hello World')
 
 
@@ -71,8 +86,37 @@ def test_esp_system_stdio_secondary_serial_jtag(dut: Dut) -> None:
 @pytest.mark.temp_skip_ci(targets=['esp32p4'], reason='p4 rev3 migration')
 def test_esp_system_stdio_correct_open_and_close(dut: Dut) -> None:
     dut.expect('2nd stage bootloader')
+    _expect_app_main_banner(dut)
     dut.expect('Hello World')
+    # Order matches test_app_main.c: stdio_fd_init_check() runs before console_open_close_check()
+    dut.expect('STDIO_TEST:FD_INIT:IN=0,OUT=1,ERR=2')
+    dut.expect('STDIO_TEST:STREAM:STDOUT')
+    dut.expect('STDIO_TEST:STREAM:STDERR')
+    dut.expect('STDIO_TEST:SELECT:LOGICAL_FD_MAP_OK')
     dut.expect('Opening /dev/console')
     dut.expect('This should be printed to stdout')
     dut.expect('Closing /dev/console')
     dut.expect('This should be printed to stdout')
+    dut.expect('STDIO_TEST:MODE=FORWARDING')
+    dut.expect('STDIO_TEST:UNIQUE_FDS_OK')
+    dut.expect('STDIO_TEST:WRITE_OK')
+    dut.expect('STDIO_TEST:FSYNC_OK')
+    dut.expect('STDIO_TEST:CLOSE_OK')
+
+
+@pytest.mark.host_test
+@pytest.mark.qemu
+@pytest.mark.parametrize(
+    'config, embedded_services',
+    [('simple', 'idf,qemu')],
+)
+@idf_parametrize('target', ['esp32'], indirect=['target'])
+def test_esp_stdio_non_basic_default_qemu(dut: Dut) -> None:
+    dut.expect('Hello World')
+    dut.expect('STDIO_TEST:FD_INIT:IN=0,OUT=1,ERR=2')
+    dut.expect('STDIO_TEST:SELECT:LOGICAL_FD_MAP_OK')
+    dut.expect('STDIO_TEST:MODE=FORWARDING')
+    dut.expect('STDIO_TEST:UNIQUE_FDS_OK')
+    dut.expect('STDIO_TEST:WRITE_OK')
+    dut.expect('STDIO_TEST:FSYNC_OK')
+    dut.expect('STDIO_TEST:CLOSE_OK')
diff --git a/components/spi_flash/test_apps/mspi_test/main/test_app_main.c b/components/spi_flash/test_apps/mspi_test/main/test_app_main.c
index abb1c1cd7dc..eaa93bad03f 100644
--- a/components/spi_flash/test_apps/mspi_test/main/test_app_main.c
+++ b/components/spi_flash/test_apps/mspi_test/main/test_app_main.c
@@ -9,7 +9,7 @@
 #include "esp_heap_caps.h"
 
 // Some resources are lazy allocated in mspi bus test, the threshold is left for that case
-#define TEST_MEMORY_LEAK_THRESHOLD (-600)
+#define TEST_MEMORY_LEAK_THRESHOLD (-650)
 
 static size_t before_free_8bit;
 static size_t before_free_32bit;