diff --git a/demos/various/SB-CLIENT-32k-08070000-16k-20018000/Makefile b/demos/various/SB-CLIENT-32k-08070000-16k-20018000/Makefile
index a3dbea483..fbee07d22 100644
--- a/demos/various/SB-CLIENT-32k-08070000-16k-20018000/Makefile
+++ b/demos/various/SB-CLIENT-32k-08070000-16k-20018000/Makefile
@@ -105,6 +105,7 @@ include $(CHIBIOS)/os/hal/hal.mk
 include $(CHIBIOS)/os/hal/ports/sandbox/platform.mk
 include $(CHIBIOS)/os/hal/boards/SB_GENERIC/board.mk
 include $(CHIBIOS)/os/hal/osal/rt-nil/osal.mk
+include $(CHIBIOS)/os/hal/lib/complex/buffered_sio/hal_buffered_sio.mk
 # RTOS files (optional).
 include $(CHIBIOS)/os/rt/rt.mk
 include $(CHIBIOS)/os/common/ports/ARMvx-M-SB/compilers/GCC/mk/port.mk
@@ -116,7 +117,7 @@ include $(CHIBIOS)/tools/mk/autobuild.mk
 #include $(CHIBIOS)/test/rt/rt_test.mk
 #include $(CHIBIOS)/test/oslib/oslib_test.mk
 include $(CHIBIOS)/os/hal/lib/streams/streams.mk
-#include $(CHIBIOS)/os/various/shell/shell.mk
+include $(CHIBIOS)/os/various/shell/shell.mk
 
 # Define linker script file here.
 LDSCRIPT= ./sandbox.ld
@@ -155,7 +156,7 @@ CPPWARN = -Wall -Wextra -Wundef
 #
 
 # List all user C define here, like -D_DEBUG=1
-UDEFS =
+UDEFS = -DSHELL_CMD_TEST_ENABLED=0
 
 # Define ASM defines here
 UADEFS =
diff --git a/demos/various/SB-CLIENT-32k-08070000-16k-20018000/main.c b/demos/various/SB-CLIENT-32k-08070000-16k-20018000/main.c
index 4f9d213bf..e87d8ad05 100644
--- a/demos/various/SB-CLIENT-32k-08070000-16k-20018000/main.c
+++ b/demos/various/SB-CLIENT-32k-08070000-16k-20018000/main.c
@@ -16,8 +16,66 @@
 
 #include "ch.h"
 #include "hal.h"
+#include "hal_buffered_sio.h"
 
 #include "chprintf.h"
+#include "shell.h"
+
+static BufferedSIODriver bsio1;
+static uint8_t rxbuf[32];
+static uint8_t txbuf[32];
+
+/*===========================================================================*/
+/* Command line related.                                                     */
+/*===========================================================================*/
+
+#define SHELL_WA_SIZE   THD_WORKING_AREA_SIZE(2048)
+
+/* Can be measured using dd if=/dev/xxxx of=/dev/null bs=512 count=10000.*/
+static void cmd_write(BaseSequentialStream *chp, int argc, char *argv[]) {
+  static uint8_t buf[] =
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef";
+
+  (void)argv;
+  if (argc > 0) {
+    chprintf(chp, "Usage: write\r\n");
+    return;
+  }
+
+  while (chnGetTimeout((BaseChannel *)chp, TIME_IMMEDIATE) == Q_TIMEOUT) {
+    chnWrite(&bsio1, buf, sizeof buf - 1);
+  }
+  chprintf(chp, "\r\n\nstopped\r\n");
+}
+
+static const ShellCommand commands[] = {
+  {"write", cmd_write},
+  {NULL, NULL}
+};
+
+static const ShellConfig shell_cfg1 = {
+  (BaseSequentialStream *)&bsio1,
+  commands
+};
+
+/*===========================================================================*/
+/* Generic code.                                                             */
+/*===========================================================================*/
 
 /*
  * Blinker thread, times are in milliseconds.
@@ -38,6 +96,7 @@ static THD_FUNCTION(Thread1, arg) {
  * Application entry point.
  */
 int main(void) {
+  thread_t *tp;
 
   /*
    * System initializations.
@@ -49,17 +108,26 @@ int main(void) {
   chSysInit();
 
   /*
-   * Activates the Serial or SIO driver using the default configuration.
+   * Starting a buffered SIO, it must behave exactly as a serial driver.
    */
-  sioStart(&SIOD1, NULL);
+  bsioObjectInit(&bsio1, &SIOD1,
+                 rxbuf, sizeof rxbuf,
+                 txbuf, sizeof txbuf);
+  bsioStart(&bsio1, NULL);
 
-  /* Creating a blinker thread.*/
+  /*
+   * Creating a blinker thread.
+   */
   chThdCreateStatic(waThread1, sizeof(waThread1), NORMALPRIO+10, Thread1, NULL);
 
-  chprintf((BaseSequentialStream *)&SIOD1, "Hello World!!\r\n");
-
-  /* Just sleeping in a loop.*/
+  /*
+   * Normal main() thread activity, spawning shells.
+   */
   while (true) {
-    chThdSleepMilliseconds(500);
+    tp = chThdCreateFromHeap(NULL, SHELL_WA_SIZE,
+                             "shell", NORMALPRIO + 1,
+                             shellThread, (void *)&shell_cfg1);
+    chThdWait(tp);               /* Waiting termination.             */
+    chThdSleepMilliseconds(1000);
   }
 }
diff --git a/os/hal/ports/sandbox/hal_sio_lld.c b/os/hal/ports/sandbox/hal_sio_lld.c
index d0735487d..1651e62fe 100644
--- a/os/hal/ports/sandbox/hal_sio_lld.c
+++ b/os/hal/ports/sandbox/hal_sio_lld.c
@@ -85,7 +85,11 @@ static inline uint32_t __sio_vuart_deinit(uint32_t nvuart) {
 #if !defined(SB_VUART1_SUPPRESS_ISR)
 OSAL_IRQ_HANDLER(MK_VECTOR(SB_SIO_VUART1_IRQ)) {
 
+  OSAL_IRQ_PROLOGUE();
+
   sio_lld_serve_interrupt(&SIOD1);
+
+  OSAL_IRQ_EPILOGUE();
 }
 #endif
 #endif
@@ -94,7 +98,11 @@ OSAL_IRQ_HANDLER(MK_VECTOR(SB_SIO_VUART1_IRQ)) {
 #if !defined(SB_VUART2_SUPPRESS_ISR)
 OSAL_IRQ_HANDLER(MK_VECTOR(SB_SIO_VUART2_IRQ)) {
 
+  OSAL_IRQ_PROLOGUE();
+
   sio_lld_serve_interrupt(&SIOD2);
+
+  OSAL_IRQ_EPILOGUE();
 }
 #endif
 #endif
@@ -454,10 +462,48 @@ void sio_lld_serve_interrupt(SIODriver *siop) {
   __syscall2rr(201, SB_VUART_GEVT, siop->nvuart);
   osalDbgAssert((msg_t)r0 == HAL_RET_SUCCESS, "unexpected failure");
 
-  /* Processing events, if any.*/
-  events = (sioevents_t)r1;
+  /* Processing enabled events, if any.*/
+  events = (sioevents_t)r1 & siop->enabled;
   if (events != (sioevents_t)0) {
 
+    /* Error events handled as a group.*/
+    if ((events & SIO_EV_ALL_ERRORS) != 0U) {
+
+      /* Waiting thread woken, if any.*/
+      __sio_wakeup_errors(siop);
+    }
+    /* If there are no errors then we check for the other RX events.*/
+    else {
+
+      /* Idle RX event.*/
+      if ((events & SIO_EV_RXIDLE) != 0U) {
+
+        /* Waiting thread woken, if any.*/
+        __sio_wakeup_rxidle(siop);
+      }
+
+      /* RX FIFO is non-empty.*/
+      if ((events & SIO_EV_RXNOTEMPY) != 0U) {
+
+        /* Waiting thread woken, if any.*/
+        __sio_wakeup_rx(siop);
+      }
+    }
+
+    /* TX FIFO is non-full.*/
+    if ((events & SIO_EV_TXNOTFULL) != 0U) {
+
+      /* Waiting thread woken, if any.*/
+      __sio_wakeup_tx(siop);
+    }
+
+    /* Physical transmission end.*/
+    if ((events & SIO_EV_TXDONE) != 0U) {
+
+      /* Waiting thread woken, if any.*/
+      __sio_wakeup_txend(siop);
+    }
+
     /* The callback is finally invoked.*/
     __sio_callback(siop);
   }
diff --git a/os/hal/ports/sandbox/hal_sio_lld.h b/os/hal/ports/sandbox/hal_sio_lld.h
index 7882818f8..6238538c4 100644
--- a/os/hal/ports/sandbox/hal_sio_lld.h
+++ b/os/hal/ports/sandbox/hal_sio_lld.h
@@ -132,6 +132,7 @@ extern "C" {
   void sio_lld_update_enable_flags(SIODriver *siop);
   sioevents_t sio_lld_get_and_clear_errors(SIODriver *siop);
   sioevents_t sio_lld_get_and_clear_events(SIODriver *siop);
+  sioevents_t sio_lld_get_events(SIODriver *siop);
   size_t sio_lld_read(SIODriver *siop, uint8_t *buffer, size_t n);
   size_t sio_lld_write(SIODriver *siop, const uint8_t *buffer, size_t n);
   msg_t sio_lld_get(SIODriver *siop);