risc-v/k210: Fix SMP interrupt stack size calculation

manual cherry-pick from #3636

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>

arch/risc-v/src/bl602/bl602_head.S

@@ -85,7 +85,7 @@ exception_common:
 
   mv   a1, sp      /* context = sp */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   /* Switch to interrupt stack */
 
   lui  sp, %hi(g_intstackbase)
@@ -150,17 +150,17 @@ exception_common:
  *  Name: g_intstackalloc and g_intstackbase
  ************************************************************************************/
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   .bss
-  .align  4
+  .balign 16
   .global g_intstackalloc
   .global g_intstackbase
   .type   g_intstackalloc, object
   .type   g_intstackbase, object
 g_intstackalloc:
-  .skip  ((CONFIG_ARCH_INTERRUPTSTACK & ~3))
+  .skip  ((CONFIG_ARCH_INTERRUPTSTACK + 8) & ~15)
 g_intstackbase:
   .skip  4
   .size  g_intstackbase, 4
-  .size  g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~3)
+  .size  g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~15)
 #endif

arch/risc-v/src/bl602/bl602_irq.c

@@ -78,10 +78,10 @@ void up_irqinitialize(void)
 
   up_irq_save();
 
-#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 3
+#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 15
   /* Colorize the interrupt stack for debug purposes */
 
-  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~3);
+  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~15);
   riscv_stack_color((FAR void *)((uintptr_t)&g_intstackbase - intstack_size),
                  intstack_size);
 #endif

arch/risc-v/src/c906/c906_head.S

@@ -191,7 +191,7 @@ exception_common:
 
   mv   a1, sp      /* context = sp */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   /* Load mhartid (cpuid) */
 
   csrr s0, mhartid
@@ -203,7 +203,7 @@ exception_common:
   j    4f
 3:
   la   sp, g_intstackbase
-  addi sp, sp, -((CONFIG_ARCH_INTERRUPTSTACK) & ~7)
+  addi sp, sp, -((CONFIG_ARCH_INTERRUPTSTACK) & ~15)
 4:
 
 #endif
@@ -264,17 +264,17 @@ exception_common:
  *  Name: g_intstackalloc and g_intstackbase
  ************************************************************************************/
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 7
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   .bss
-  .align  8
+  .balign 16
   .global g_intstackalloc
   .global g_intstackbase
   .type   g_intstackalloc, object
   .type   g_intstackbase, object
 g_intstackalloc:
-  .skip  (((CONFIG_ARCH_INTERRUPTSTACK * 2) & ~7))
+  .skip  ((CONFIG_ARCH_INTERRUPTSTACK + 8) & ~15)
 g_intstackbase:
   .skip  8
   .size  g_intstackbase, 8
-  .size  g_intstackalloc, ((CONFIG_ARCH_INTERRUPTSTACK * 2) & ~7)
+  .size  g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~15)
 #endif

arch/risc-v/src/c906/c906_irq.c

@@ -72,8 +72,8 @@ void up_irqinitialize(void)
 
   /* Colorize the interrupt stack for debug purposes */
 
-#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 7
-  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~7);
+#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 15
+  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~15);
   riscv_stack_color((FAR void *)((uintptr_t)&g_intstackbase - intstack_size),
                  intstack_size);
 #endif

arch/risc-v/src/common/riscv_checkstack.c

@@ -191,17 +191,17 @@ ssize_t up_check_stack_remain(void)
   return up_check_tcbstack_remain(this_task());
 }
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
 size_t up_check_intstack(void)
 {
   return do_stackcheck((uintptr_t)&g_intstackalloc,
-                       (CONFIG_ARCH_INTERRUPTSTACK & ~3),
+                       (CONFIG_ARCH_INTERRUPTSTACK & ~15),
                        true);
 }
 
 size_t up_check_intstack_remain(void)
 {
-  return (CONFIG_ARCH_INTERRUPTSTACK & ~3) - up_check_intstack();
+  return (CONFIG_ARCH_INTERRUPTSTACK & ~15) - up_check_intstack();
 }
 #endif
 

arch/risc-v/src/common/riscv_createstack.c

@@ -42,20 +42,13 @@
  * Pre-processor Macros
  ****************************************************************************/
 
-/* RISC-V requires at least a 4-byte stack alignment.
- * For floating point use, however, the stack must be aligned to 8-byte
- * addresses.
- */
+/* RISC-V requires a 16-byte stack alignment. */
 
-#if defined(CONFIG_LIBC_FLOATINGPOINT) || defined (CONFIG_ARCH_RV64GC)
-#  define STACK_ALIGNMENT   8
-#else
-#  define STACK_ALIGNMENT   4
-#endif
+#define STACK_ALIGNMENT     16
 
 /* Stack alignment macros */
 
-#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT - 1)
 #define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
 #define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
 

arch/risc-v/src/common/riscv_initialize.c

@@ -53,13 +53,13 @@
  *
  ****************************************************************************/
 
-#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 3
+#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 15
 static inline void up_color_intstack(void)
 {
   uint32_t *ptr = (uint32_t *)&g_intstackalloc;
   ssize_t size;
 
-  for (size = (CONFIG_ARCH_INTERRUPTSTACK & ~3);
+  for (size = (CONFIG_ARCH_INTERRUPTSTACK & ~15);
        size > 0;
        size -= sizeof(uint32_t))
     {

arch/risc-v/src/common/riscv_internal.h

@@ -133,7 +133,7 @@ EXTERN uint32_t g_idle_topstack;
 
 /* Address of the saved user stack pointer */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
 EXTERN uint32_t g_intstackalloc; /* Allocated stack base */
 EXTERN uint32_t g_intstackbase;  /* Initial top of interrupt stack */
 #endif

arch/risc-v/src/common/riscv_stackframe.c

@@ -37,20 +37,13 @@
  * Pre-processor Macros
  ****************************************************************************/
 
-/* RISC-V requires at least a 4-byte stack alignment.
- * For floating point use, however, the stack must be aligned to 8-byte
- * addresses.
- */
+/* RISC-V requires a 16-byte stack alignment. */
 
-#if defined(CONFIG_LIBC_FLOATINGPOINT) || defined (CONFIG_ARCH_RV64GC)
-#  define STACK_ALIGNMENT   8
-#else
-#  define STACK_ALIGNMENT   4
-#endif
+#define STACK_ALIGNMENT     16
 
 /* Stack alignment macros */
 
-#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT - 1)
 #define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
 #define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
 

arch/risc-v/src/common/riscv_usestack.c

@@ -39,20 +39,13 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-/* RISC-V requires at least a 4-byte stack alignment.
- * For floating point use, however, the stack must be aligned to 8-byte
- * addresses.
- */
+/* RISC-V requires a 16-byte stack alignment. */
 
-#if defined(CONFIG_LIBC_FLOATINGPOINT) || defined (CONFIG_ARCH_RV64GC)
-#  define STACK_ALIGNMENT   8
-#else
-#  define STACK_ALIGNMENT   4
-#endif
+#define STACK_ALIGNMENT     16
 
 /* Stack alignment macros */
 
-#define STACK_ALIGN_MASK    (STACK_ALIGNMENT-1)
+#define STACK_ALIGN_MASK    (STACK_ALIGNMENT - 1)
 #define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
 #define STACK_ALIGN_UP(a)   (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
 

arch/risc-v/src/esp32c3/esp32c3_allocateheap.c

@@ -34,6 +34,8 @@
 
 #include "esp32c3.h"
 
+#include "hardware/esp32c3_rom_layout.h"
+
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -64,12 +66,13 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
    */
 
   extern uint8_t *_sheap;
-  extern uint8_t *_eheap;
+  extern const struct esp32c3_rom_layout_s *ets_rom_layout_p;
 
   board_autoled_on(LED_HEAPALLOCATE);
 
   *heap_start = (FAR void *)&_sheap;
-  *heap_size = (size_t)((uintptr_t)&_eheap - (uintptr_t)&_sheap);
+  *heap_size = (size_t)(ets_rom_layout_p->dram0_rtos_reserved_start -
+                        (uintptr_t)&_sheap);
 }
 
 /****************************************************************************

arch/risc-v/src/esp32c3/esp32c3_interrupt.S

@@ -43,13 +43,13 @@
   .section  .noinit
 
 #if CONFIG_ARCH_INTERRUPTSTACK > 15
-  .align    4
+  .balign   16
   .type     g_intstackalloc, @object
   .type     g_intstackbase,  @object
 g_intstackalloc:
-  .skip     CONFIG_ARCH_INTERRUPTSTACK
+  .skip     ((CONFIG_ARCH_INTERRUPTSTACK + 8) & ~15)
 g_intstackbase:
-  .size     g_intstackalloc, CONFIG_ARCH_INTERRUPTSTACK
+  .size     g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~15)
 #endif
 
 /****************************************************************************

arch/risc-v/src/esp32c3/hardware/esp32c3_rom_layout.h

@@ -0,0 +1,94 @@
+/****************************************************************************
+ * arch/risc-v/src/esp32c3/hardware/esp32c3_rom_layout.h
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_ESP32C3_HARDWARE_ESP32C3_ROM_LAYOUT_H
+#define __ARCH_RISCV_SRC_ESP32C3_HARDWARE_ESP32C3_ROM_LAYOUT_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <stdint.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Structure and functions for returning ROM global layout
+ *
+ * This is for address symbols defined in the linker script,
+ * which may change during ECOs.
+ */
+
+struct esp32c3_rom_layout_s
+{
+  uintptr_t dram0_stack_shared_mem_start;
+  uintptr_t dram0_rtos_reserved_start;
+  uintptr_t stack_sentry;
+  uintptr_t stack;
+  uintptr_t stack_sentry_app;
+  uintptr_t stack_app;
+
+  /* BTDM data */
+
+  uintptr_t data_start_btdm;
+  uintptr_t data_end_btdm;
+  uintptr_t bss_start_btdm;
+  uintptr_t bss_end_btdm;
+  uintptr_t data_start_btdm_rom;
+  uintptr_t data_end_btdm_rom;
+  uintptr_t data_start_interface_btdm;
+  uintptr_t data_end_interface_btdm;
+  uintptr_t bss_start_interface_btdm;
+  uintptr_t bss_end_interface_btdm;
+
+  /* PHY data */
+
+  uintptr_t dram_start_phyrom;
+  uintptr_t dram_end_phyrom;
+
+  /* Wi-Fi data */
+
+  uintptr_t dram_start_coexist;
+  uintptr_t dram_end_coexist;
+  uintptr_t dram_start_net80211;
+  uintptr_t dram_end_net80211;
+  uintptr_t dram_start_pp;
+  uintptr_t dram_end_pp;
+  uintptr_t data_start_interface_coexist;
+  uintptr_t data_end_interface_coexist;
+  uintptr_t bss_start_interface_coexist;
+  uintptr_t bss_end_interface_coexist;
+  uintptr_t data_start_interface_net80211;
+  uintptr_t data_end_interface_net80211;
+  uintptr_t bss_start_interface_net80211;
+  uintptr_t bss_end_interface_net80211;
+  uintptr_t data_start_interface_pp;
+  uintptr_t data_end_interface_pp;
+  uintptr_t bss_start_interface_pp;
+  uintptr_t bss_end_interface_pp;
+  uintptr_t dram_start_usbdev_rom;
+  uintptr_t dram_end_usbdev_rom;
+  uintptr_t dram_start_uart_rom;
+  uintptr_t dram_end_uart_rom;
+};
+
+#endif /* __ARCH_RISCV_SRC_ESP32C3_HARDWARE_ESP32C3_ROM_LAYOUT_H */
+

arch/risc-v/src/fe310/fe310_head.S

@@ -126,7 +126,7 @@ exception_common:
 
   mv   a1, sp      /* context = sp */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   /* Switch to interrupt stack */
 
   lui  sp, %hi(g_intstackbase)
@@ -188,17 +188,17 @@ exception_common:
  *  Name: g_intstackalloc and g_intstackbase
  ************************************************************************************/
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   .bss
-  .align  4
+  .balign 16
   .global g_intstackalloc
   .global g_intstackbase
   .type   g_intstackalloc, object
   .type   g_intstackbase, object
 g_intstackalloc:
-  .skip  ((CONFIG_ARCH_INTERRUPTSTACK & ~3))
+  .skip  ((CONFIG_ARCH_INTERRUPTSTACK + 8) & ~15)
 g_intstackbase:
   .skip  4
   .size  g_intstackbase, 4
-  .size  g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~3)
+  .size  g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~15)
 #endif

arch/risc-v/src/fe310/fe310_irq.c

@@ -59,8 +59,8 @@ void up_irqinitialize(void)
 
   /* Colorize the interrupt stack for debug purposes */
 
-#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 3
-  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~3);
+#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 15
+  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~15);
   riscv_stack_color((FAR void *)((uintptr_t)&g_intstackbase - intstack_size),
                  intstack_size);
 #endif

arch/risc-v/src/k210/k210_head.S

@@ -143,7 +143,7 @@ normal_irq:
 
   mv   a1, sp      /* context = sp */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   /* Load mhartid (cpuid) */
 
   csrr s0, mhartid
@@ -155,7 +155,7 @@ normal_irq:
   j    4f
 3:
   la   sp, g_intstackbase
-  addi sp, sp, -((CONFIG_ARCH_INTERRUPTSTACK) & ~7)
+  addi sp, sp, -((CONFIG_ARCH_INTERRUPTSTACK) & ~15)
 4:
 
 #endif
@@ -215,17 +215,25 @@ normal_irq:
  *  Name: g_intstackalloc and g_intstackbase
  ************************************************************************************/
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 7
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   .bss
-  .align  8
+  .balign 16
   .global g_intstackalloc
   .global g_intstackbase
   .type   g_intstackalloc, object
   .type   g_intstackbase, object
 g_intstackalloc:
-  .skip  (((CONFIG_ARCH_INTERRUPTSTACK * 2) & ~7))
+#ifndef CONFIG_SMP
+  .skip  ((CONFIG_ARCH_INTERRUPTSTACK + 8) & ~15)
+#else
+  .skip  (((CONFIG_ARCH_INTERRUPTSTACK * CONFIG_SMP_NCPUS) + 8) & ~15)
+#endif
 g_intstackbase:
   .skip  8
   .size  g_intstackbase, 8
-  .size  g_intstackalloc, ((CONFIG_ARCH_INTERRUPTSTACK * 2) & ~7)
+#ifndef CONFIG_SMP
+  .size  g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~15)
+#else
+  .size  g_intstackalloc, ((CONFIG_ARCH_INTERRUPTSTACK * CONFIG_SMP_NCPUS) & ~15)
+#endif
 #endif

arch/risc-v/src/k210/k210_irq.c

@@ -80,8 +80,13 @@ void up_irqinitialize(void)
 
   /* Colorize the interrupt stack for debug purposes */
 
-#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 7
-  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~7);
+#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 15
+  size_t intstack_size = 0;
+#ifndef CONFIG_SMP
+  intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~15);
+#else
+  intstack_size = ((CONFIG_ARCH_INTERRUPTSTACK * CONFIG_SMP_NCPUS) & ~15);
+#endif
   riscv_stack_color((FAR void *)((uintptr_t)&g_intstackbase - intstack_size),
                  intstack_size);
 #endif

arch/risc-v/src/litex/litex_head.S

@@ -126,7 +126,7 @@ exception_common:
 
   mv   a1, sp      /* context = sp */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   /* Switch to interrupt stack */
 
   lui  sp, %hi(g_intstackbase)
@@ -188,17 +188,17 @@ exception_common:
  *  Name: g_intstackalloc and g_intstackbase
  ************************************************************************************/
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   .bss
-  .align  4
+  .balign 16
   .global g_intstackalloc
   .global g_intstackbase
   .type   g_intstackalloc, object
   .type   g_intstackbase, object
 g_intstackalloc:
-  .skip  ((CONFIG_ARCH_INTERRUPTSTACK & ~3))
+  .skip  ((CONFIG_ARCH_INTERRUPTSTACK + 8) & ~15)
 g_intstackbase:
   .skip  4
   .size  g_intstackbase, 4
-  .size  g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~3)
+  .size  g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~15)
 #endif

arch/risc-v/src/litex/litex_irq.c

@@ -58,8 +58,8 @@ void up_irqinitialize(void)
 
   /* Colorize the interrupt stack for debug purposes */
 
-#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 3
-  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~3);
+#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 15
+  size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~15);
   riscv_stack_color((FAR void *)((uintptr_t)&g_intstackbase - intstack_size),
                  intstack_size);
 #endif

arch/risc-v/src/rv32im/riscv_assert.c

@@ -173,7 +173,7 @@ static void riscv_dumpstate(void)
   uint32_t sp = riscv_getsp();
   uint32_t ustackbase;
   uint32_t ustacksize;
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   uint32_t istackbase;
   uint32_t istacksize;
 #endif
@@ -189,9 +189,9 @@ static void riscv_dumpstate(void)
 
   /* Get the limits on the interrupt stack memory */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 3
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   istackbase = (uint32_t)&g_intstackbase;
-  istacksize = (CONFIG_ARCH_INTERRUPTSTACK & ~3) - 4;
+  istacksize = (CONFIG_ARCH_INTERRUPTSTACK & ~15) - 4;
 
   /* Show interrupt stack info */
 

arch/risc-v/src/rv32im/riscv_vfork.c

@@ -41,10 +41,6 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-#ifndef CONFIG_STACK_ALIGNMENT
-#  define CONFIG_STACK_ALIGNMENT 4
-#endif
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/

arch/risc-v/src/rv64gc/riscv_assert.c

@@ -184,7 +184,7 @@ static void up_dumpstate(void)
   uint64_t sp = riscv_getsp();
   uintptr_t ustackbase;
   uintptr_t ustacksize;
-#if CONFIG_ARCH_INTERRUPTSTACK > 7
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   uintptr_t istackbase;
   uintptr_t istacksize;
 #endif
@@ -200,9 +200,9 @@ static void up_dumpstate(void)
 
   /* Get the limits on the interrupt stack memory */
 
-#if CONFIG_ARCH_INTERRUPTSTACK > 7
+#if CONFIG_ARCH_INTERRUPTSTACK > 15
   istackbase = (uintptr_t)&g_intstackbase;
-  istacksize = (CONFIG_ARCH_INTERRUPTSTACK & ~7) - 8;
+  istacksize = (CONFIG_ARCH_INTERRUPTSTACK & ~15) - 8;
 
   /* Show interrupt stack info */
 

arch/xtensa/src/esp32/esp32_wifi_adapter.c

@@ -1802,8 +1802,10 @@ static int32_t esp_task_create_pinned_to_core(void *entry,
                       (char * const *)param);
   if (pid > 0)
     {
-      *((int *)task_handle) = pid;
-
+      if (task_handle != NULL)
+        {
+          *((int *)task_handle) = pid;
+        }
 #ifdef CONFIG_SMP
       if (core_id < CONFIG_SMP_NCPUS)
         {

boards/arm/cxd56xx/common/src/cxd56_gs2200m.c

@@ -47,6 +47,20 @@
 #define SPI_TX_MAXSIZE (CONFIG_CXD56_DMAC_SPI5_TX_MAXSIZE)
 #define SPI_RX_MAXSIZE (CONFIG_CXD56_DMAC_SPI5_RX_MAXSIZE)
 
+#if defined(CONFIG_WIFI_BOARD_IS110B_HARDWARE_VERSION_10B)
+/* v1.0b */
+#define GS2200M_GPIO_37          (PIN_UART2_CTS)
+#define GS2200M_EXT_RTC_RESET_IN (PIN_EMMC_DATA3)
+#elif defined(CONFIG_WIFI_BOARD_IS110B_HARDWARE_VERSION_10C)
+/* v1.0c */
+#define GS2200M_GPIO_37          (PIN_EMMC_DATA2)
+#define GS2200M_EXT_RTC_RESET_IN (PIN_EMMC_DATA3)
+#else
+/* v1.0a */
+#define GS2200M_GPIO_37          (PIN_UART2_CTS)
+#define GS2200M_EXT_RTC_RESET_IN (PIN_UART2_RTS)
+#endif
+
 /****************************************************************************
  * Private Function Prototypes
  ****************************************************************************/
@@ -84,7 +98,7 @@ static volatile uint32_t _n_called;
 
 static int gs2200m_irq_attach(xcpt_t handler, FAR void *arg)
 {
-  cxd56_gpioint_config(PIN_UART2_CTS,
+  cxd56_gpioint_config(GS2200M_GPIO_37,
                        GPIOINT_LEVEL_HIGH,
                        handler,
                        arg);
@@ -104,7 +118,7 @@ static void gs2200m_irq_enable(void)
 
   if (0 == _enable_count)
     {
-      cxd56_gpioint_enable(PIN_UART2_CTS);
+      cxd56_gpioint_enable(GS2200M_GPIO_37);
     }
 
   _enable_count++;
@@ -127,7 +141,7 @@ static void gs2200m_irq_disable(void)
 
   if (0 == _enable_count)
     {
-      cxd56_gpioint_disable(PIN_UART2_CTS);
+      cxd56_gpioint_disable(GS2200M_GPIO_37);
     }
 
   leave_critical_section(flags);
@@ -141,7 +155,7 @@ static uint32_t gs2200m_dready(int *ec)
 {
   irqstate_t flags = enter_critical_section();
 
-  uint32_t r = cxd56_gpio_read(PIN_UART2_CTS);
+  uint32_t r = cxd56_gpio_read(GS2200M_GPIO_37);
 
   if (ec)
     {
@@ -160,7 +174,7 @@ static uint32_t gs2200m_dready(int *ec)
 
 static void gs2200m_reset(bool reset)
 {
-  cxd56_gpio_write(PIN_UART2_RTS, !reset);
+  cxd56_gpio_write(GS2200M_EXT_RTC_RESET_IN, !reset);
 }
 
 /****************************************************************************
@@ -222,8 +236,8 @@ int board_gs2200m_initialize(FAR const char *devpath, int bus)
       /* Change UART2 to GPIO */
 
       CXD56_PIN_CONFIGS(PINCONFS_UART2_GPIO);
-      cxd56_gpio_config(PIN_UART2_CTS, true);
-      cxd56_gpio_config(PIN_UART2_RTS, false);
+      cxd56_gpio_config(GS2200M_GPIO_37, true);
+      cxd56_gpio_config(GS2200M_EXT_RTC_RESET_IN, false);
 
       /* Initialize spi device */
 

boards/arm/cxd56xx/spresense/Kconfig

@@ -515,6 +515,23 @@ config LCD_ON_MAIN_BOARD
 
 endchoice
 endif
+
+choice
+	prompt "Spresense Wi-Fi Add-on board (iS110B)"
+	default WIFI_BOARD_IS110B_HARDWARE_VERSION_10A
+	---help---
+		Specify the hardware version of Wi-Fi Add-on board (iS110B)
+
+config WIFI_BOARD_IS110B_HARDWARE_VERSION_10A
+	bool "WIFI Board iS110B v1.0A"
+
+config WIFI_BOARD_IS110B_HARDWARE_VERSION_10B
+	bool "WIFI Board iS110B v1.0B"
+
+config WIFI_BOARD_IS110B_HARDWARE_VERSION_10C
+	bool "WIFI Board iS110B v1.0C"
+endchoice
+
 comment "LTE Options"
 
 menuconfig CXD56_LTE

boards/risc-v/esp32c3/esp32c3-devkit/scripts/esp32c3.template.ld

@@ -82,10 +82,6 @@ MEMORY
 
 }
 
-/* Heap ends at the start of the static data of the ROM bootloader */
-
-_eheap = 0x3fccae00;
-
 #if CONFIG_ESP32C3_DEVKIT_RUN_IRAM
   REGION_ALIAS("default_rodata_seg", dram0_0_seg);
   REGION_ALIAS("default_code_seg", iram0_0_seg);

drivers/wireless/gs2200m.c

@@ -650,7 +650,7 @@ static bool _copy_data_from_pkt(FAR struct gs2200m_dev_s *dev,
 
   pkt_dat->remain -= len;
 
-  if (0 == pkt_dat->remain)
+  if (0 == pkt_dat->remain || TYPE_BULK_DATA_UDP == pkt_dat->type)
     {
       _remove_and_free_pkt(dev, c);
     }
@@ -1568,6 +1568,27 @@ errout:
   return r;
 }
 
+/****************************************************************************
+ * Name: gs2200m_send_cmd2
+ ****************************************************************************/
+
+static enum pkt_type_e gs2200m_send_cmd2(FAR struct gs2200m_dev_s *dev,
+                                         FAR char *cmd)
+{
+  struct pkt_dat_s pkt_dat;
+  enum pkt_type_e  r;
+
+  /* Initialize pkt_dat and send */
+
+  memset(&pkt_dat, 0, sizeof(pkt_dat));
+  r = gs2200m_send_cmd(dev, cmd, &pkt_dat);
+
+  /* Release the pkt_dat */
+
+  _release_pkt_dat(dev, &pkt_dat);
+  return r;
+}
+
 /****************************************************************************
  * Name: gs2200m_set_opmode
  * NOTE: See 5.1.2 Operation Mode
@@ -1580,7 +1601,7 @@ static enum pkt_type_e gs2200m_set_opmode(FAR struct gs2200m_dev_s *dev,
   char cmd[20];
 
   snprintf(cmd, sizeof(cmd), "AT+WM=%d\r\n", mode);
-  t = gs2200m_send_cmd(dev, cmd, NULL);
+  t = gs2200m_send_cmd2(dev, cmd);
 
   if (TYPE_OK == t)
     {
@@ -1636,7 +1657,7 @@ errout:
 
 static enum pkt_type_e gs2200m_disassociate(FAR struct gs2200m_dev_s *dev)
 {
-  return gs2200m_send_cmd(dev, (char *)"AT+WD\r\n", NULL);
+  return gs2200m_send_cmd2(dev, (char *)"AT+WD\r\n");
 }
 
 /****************************************************************************
@@ -1650,7 +1671,7 @@ static enum pkt_type_e gs2200m_enable_dhcpc(FAR struct gs2200m_dev_s *dev,
   char cmd[16];
 
   snprintf(cmd, sizeof(cmd), "AT+NDHCP=%d\r\n", on);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -1664,7 +1685,7 @@ static enum pkt_type_e gs2200m_calc_key(FAR struct gs2200m_dev_s *dev,
   char cmd[80];
 
   snprintf(cmd, sizeof(cmd), "AT+WPAPSK=%s,%s\r\n", ssid, psk);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -1678,7 +1699,7 @@ static enum pkt_type_e gs2200m_set_security(FAR struct gs2200m_dev_s *dev,
   char cmd[16];
 
   snprintf(cmd, sizeof(cmd), "AT+WSEC=%d\r\n", mode);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -1749,7 +1770,8 @@ static enum pkt_type_e gs2200m_set_addresses(FAR struct gs2200m_dev_s *dev,
 
   snprintf(cmd, sizeof(cmd), "AT+NSET=%s,%s,%s\r\n",
            address, netmask, gateway);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -1763,7 +1785,7 @@ static enum pkt_type_e gs2200m_enable_dhcps(FAR struct gs2200m_dev_s *dev,
   char cmd[20];
 
   snprintf(cmd, sizeof(cmd), "AT+DHCPSRVR=%d\r\n", on);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -1777,7 +1799,7 @@ static enum pkt_type_e gs2200m_set_auth(FAR struct gs2200m_dev_s *dev,
   char cmd[16];
 
   snprintf(cmd, sizeof(cmd), "AT+WAUTH=%d\r\n", mode);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 #ifdef CONFIG_WL_GS2200M_ENABLE_WEP
@@ -1793,7 +1815,7 @@ static enum pkt_type_e gs2200m_set_wepkey(FAR struct gs2200m_dev_s *dev,
   char cmd[32];
 
   snprintf(cmd, sizeof(cmd), "AT+WWEP1=%s\r\n", key);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 #else
@@ -1809,7 +1831,7 @@ static enum pkt_type_e gs2200m_set_wpa2pf(FAR struct gs2200m_dev_s *dev,
   char cmd[64];
 
   snprintf(cmd, sizeof(cmd), "AT+WWPA=%s\r\n", key);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 #endif /* CONFIG_WL_GS2200M_ENABLE_WEP */
@@ -2038,21 +2060,10 @@ static enum pkt_type_e gs2200m_send_bulk(FAR struct gs2200m_dev_s *dev,
 static enum pkt_type_e gs2200m_close_conn(FAR struct gs2200m_dev_s *dev,
                                           char cid)
 {
-  struct pkt_dat_s pkt_dat;
-  enum pkt_type_e   r;
   char cmd[15];
 
-  /* Prepare cmd */
-
   snprintf(cmd, sizeof(cmd), "AT+NCLOSE=%c\r\n", cid);
-
-  /* Initialize pkt_dat and send */
-
-  memset(&pkt_dat, 0, sizeof(pkt_dat));
-  r = gs2200m_send_cmd(dev, cmd, &pkt_dat);
-
-  _release_pkt_dat(dev, &pkt_dat);
-  return r;
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -2066,7 +2077,7 @@ static enum pkt_type_e gs2200m_enable_bulk(FAR struct gs2200m_dev_s *dev,
   char cmd[20];
 
   snprintf(cmd, sizeof(cmd), "AT+BDATA=%d\r\n", on);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -2080,7 +2091,7 @@ static enum pkt_type_e gs2200m_enable_echo(FAR struct gs2200m_dev_s *dev,
   char cmd[8];
 
   snprintf(cmd, sizeof(cmd), "ATE%d\r\n", on);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -2094,7 +2105,7 @@ static enum pkt_type_e gs2200m_activate_wrx(FAR struct gs2200m_dev_s *dev,
   char cmd[30];
 
   snprintf(cmd, sizeof(cmd), "AT+WRXACTIVE=%d\r\n", on);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 
 /****************************************************************************
@@ -2109,7 +2120,7 @@ static enum pkt_type_e gs2200m_set_gpio(FAR struct gs2200m_dev_s *dev,
   char cmd[24];
 
   snprintf(cmd, sizeof(cmd), "AT+DGPIO=%d,%d\r\n", n, val);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 #endif
 
@@ -2125,7 +2136,7 @@ static enum pkt_type_e gs2200m_set_loglevel(FAR struct gs2200m_dev_s *dev,
   char cmd[16];
 
   snprintf(cmd, sizeof(cmd), "AT+LOGLVL=%d\r\n", level);
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 #endif
 
@@ -2139,7 +2150,7 @@ static enum pkt_type_e gs2200m_get_version(FAR struct gs2200m_dev_s *dev)
   char cmd[16];
 
   snprintf(cmd, sizeof(cmd), "AT+VER=??\r\n");
-  return gs2200m_send_cmd(dev, cmd, NULL);
+  return gs2200m_send_cmd2(dev, cmd);
 }
 #endif
 

fs/inode/fs_files.c

@@ -369,7 +369,7 @@ int fs_getfilep(int fd, FAR struct file **filep)
       _files_semgive(list);
     }
 
-  return OK;
+  return ret;
 }
 
 /****************************************************************************

include/net/if.h

@@ -44,6 +44,7 @@
 #define IFF_UP             (1 << 1) /* Interface is up */
 #define IFF_RUNNING        (1 << 2) /* Carrier is available */
 #define IFF_IPv6           (1 << 3) /* Configured for IPv6 packet (vs ARP or IPv4) */
+#define IFF_BOUND          (1 << 4) /* Bound to a socket */
 #define IFF_NOARP          (1 << 7) /* ARP is not required for this packet */
 
 /* Interface flag helpers */
@@ -51,20 +52,23 @@
 #define IFF_SET_DOWN(f)    do { (f) |= IFF_DOWN; } while (0)
 #define IFF_SET_UP(f)      do { (f) |= IFF_UP; } while (0)
 #define IFF_SET_RUNNING(f) do { (f) |= IFF_RUNNING; } while (0)
+#define IFF_SET_BOUND(f)   do { (f) |= IFF_BOUND; } while (0)
 #define IFF_SET_NOARP(f)   do { (f) |= IFF_NOARP; } while (0)
 
 #define IFF_CLR_DOWN(f)    do { (f) &= ~IFF_DOWN; } while (0)
 #define IFF_CLR_UP(f)      do { (f) &= ~IFF_UP; } while (0)
 #define IFF_CLR_RUNNING(f) do { (f) &= ~IFF_RUNNING; } while (0)
+#define IFF_CLR_BOUND(f)   do { (f) &= ~IFF_BOUND; } while (0)
 #define IFF_CLR_NOARP(f)   do { (f) &= ~IFF_NOARP; } while (0)
 
 #define IFF_IS_DOWN(f)     (((f) & IFF_DOWN) != 0)
 #define IFF_IS_UP(f)       (((f) & IFF_UP) != 0)
 #define IFF_IS_RUNNING(f)  (((f) & IFF_RUNNING) != 0)
+#define IFF_IS_BOUND(f)    (((f) & IFF_BOUND) != 0)
 #define IFF_IS_NOARP(f)    (((f) & IFF_NOARP) != 0)
 
 /* We only need to manage the IPv6 bit if both IPv6 and IPv4 are supported.
- *  Otherwise, we can save a few bytes by ignoring it.
+ * Otherwise, we can save a few bytes by ignoring it.
  */
 
 #if defined(CONFIG_NET_IPv4) && defined(CONFIG_NET_IPv6)

include/nuttx/arch.h

@@ -1354,39 +1354,6 @@ void up_irqinitialize(void);
 
 bool up_interrupt_context(void);
 
-/****************************************************************************
- * Name: up_irq_save
- *
- * Description:
- *   Save the current interrupt state and disable interrupts.
- *
- * Input Parameters:
- *   None
- *
- * Returned Value:
- *   Interrupt state prior to disabling interrupts.
- *
- ****************************************************************************/
-
-irqstate_t up_irq_save(void);
-
-/****************************************************************************
- * Name: up_irq_restore
- *
- * Description:
- *   Restore the previous irq state (i.e., the one previously
- *   returned by up_irq_save())
- *
- * Input Parameters:
- *   irqstate - The interrupt state to be restored.
- *
- * Returned Value:
- *   None
- *
- ****************************************************************************/
-
-void up_irq_restore(irqstate_t irqstate);
-
 /****************************************************************************
  * Name: up_enable_irq
  *

net/devif/ipv4_input.c

@@ -297,7 +297,14 @@ int ipv4_input(FAR struct net_driver_s *dev)
             }
           else
 #endif
-          if (ipv4->proto != IP_PROTO_UDP)
+#if defined(NET_UDP_HAVE_STACK) && defined(CONFIG_NET_UDP_BINDTODEVICE)
+          /* If the UDP protocol specific socket option UDP_BINDTODEVICE
+           * is selected, then we must forward all UDP packets to the bound
+           * socket.
+           */
+
+          if (ipv4->proto != IP_PROTO_UDP || !IFF_IS_BOUND(dev->d_flags))
+#endif
             {
               /* Not destined for us and not forwardable... Drop the
                * packet.

net/devif/ipv6_input.c

@@ -433,7 +433,14 @@ int ipv6_input(FAR struct net_driver_s *dev)
             }
           else
 #endif
-          if (nxthdr != IP_PROTO_UDP)
+#if defined(NET_UDP_HAVE_STACK) && defined(CONFIG_NET_UDP_BINDTODEVICE)
+          /* If the UDP protocol specific socket option UDP_BINDTODEVICE
+           * is selected, then we must forward all UDP packets to the bound
+           * socket.
+           */
+
+          if (nxthdr != IP_PROTO_UDP || !IFF_IS_BOUND(dev->d_flags))
+#endif
             {
               /* Not destined for us and not forwardable...
                * drop the packet.

net/local/local_sendmsg.c

@@ -156,8 +156,7 @@ static ssize_t local_sendto(FAR struct socket *psock,
 #ifdef CONFIG_NET_LOCAL_DGRAM
   FAR struct local_conn_s *conn = (FAR struct local_conn_s *)psock->s_conn;
   FAR struct sockaddr_un *unaddr = (FAR struct sockaddr_un *)to;
-  ssize_t nsent;
-  int ret;
+  ssize_t ret;
 
   /* Verify that a valid address has been provided */
 
@@ -212,7 +211,7 @@ static ssize_t local_sendto(FAR struct socket *psock,
   ret = local_create_halfduplex(conn, unaddr->sun_path);
   if (ret < 0)
     {
-      nerr("ERROR: Failed to create FIFO for %s: %d\n",
+      nerr("ERROR: Failed to create FIFO for %s: %zd\n",
            conn->lc_path, ret);
       return ret;
     }
@@ -224,25 +223,18 @@ static ssize_t local_sendto(FAR struct socket *psock,
                           (flags & MSG_DONTWAIT) != 0);
   if (ret < 0)
     {
-      nerr("ERROR: Failed to open FIFO for %s: %d\n",
+      nerr("ERROR: Failed to open FIFO for %s: %zd\n",
            unaddr->sun_path, ret);
 
-      nsent = ret;
       goto errout_with_halfduplex;
     }
 
   /* Send the packet */
 
-  nsent = local_send_packet(&conn->lc_outfile, buf, len);
-  if (nsent < 0)
+  ret = local_send_packet(&conn->lc_outfile, buf, len);
+  if (ret < 0)
     {
-      nerr("ERROR: Failed to send the packet: %d\n", ret);
-    }
-  else
-    {
-      /* local_send_packet returns 0 if all 'len' bytes were sent */
-
-      nsent = len;
+      nerr("ERROR: Failed to send the packet: %zd\n", ret);
     }
 
   /* Now we can close the write-only socket descriptor */
@@ -255,7 +247,8 @@ errout_with_halfduplex:
   /* Release our reference to the half duplex FIFO */
 
   local_release_halfduplex(conn);
-  return nsent;
+
+  return ret;
 #else
   return -EISCONN;
 #endif /* CONFIG_NET_LOCAL_DGRAM */

net/udp/udp_close.c

@@ -29,10 +29,14 @@
 #include <debug.h>
 #include <assert.h>
 
+#include <net/if.h>
+
 #include <nuttx/net/net.h>
+#include <nuttx/net/netdev.h>
 #include <nuttx/net/udp.h>
 
 #include "devif/devif.h"
+#include "netdev/netdev.h"
 #include "udp/udp.h"
 #include "socket/socket.h"
 
@@ -63,7 +67,7 @@ int udp_close(FAR struct socket *psock)
   unsigned int timeout = UINT_MAX;
   int ret;
 
-  /* Interrupts are disabled here to avoid race conditions */
+  /* Lock the network to avoid race conditions */
 
   net_lock();
 
@@ -102,6 +106,28 @@ int udp_close(FAR struct socket *psock)
       nerr("ERROR: udp_txdrain() failed: %d\n", ret);
     }
 
+#ifdef CONFIG_NET_UDP_BINDTODEVICE
+  /* Is the socket bound to an interface device */
+
+  if (conn->boundto != 0)
+    {
+      FAR struct net_driver_s *dev;
+
+      /* Yes, get the interface that we are bound do.  NULL would indicate
+       * that the interface no longer exists for some reason.
+       */
+
+      dev = netdev_findbyindex(conn->boundto);
+      if (dev != NULL)
+        {
+          /* Clear the interface flag to unbind the device from the socket.
+           */
+
+          IFF_CLR_BOUND(dev->d_flags);
+        }
+    }
+#endif
+
 #ifdef CONFIG_NET_UDP_WRITE_BUFFERS
   /* Free any semi-permanent write buffer callback in place. */
 

net/udp/udp_setsockopt.c

@@ -29,9 +29,11 @@
 #include <assert.h>
 #include <debug.h>
 
+#include <net/if.h>
 #include <netinet/udp.h>
 
 #include <nuttx/net/net.h>
+#include <nuttx/net/netdev.h>
 #include <nuttx/net/udp.h>
 
 #include "socket/socket.h"
@@ -112,31 +114,74 @@ int udp_setsockopt(FAR struct socket *psock, int option,
        */
 
       case UDP_BINDTODEVICE:  /* Bind socket to a specific network device */
-        if (value == NULL || value_len == 0 ||
-           (value_len > 0 && ((FAR char *)value)[0] == 0))
-          {
-            conn->boundto = 0;  /* This interface is no longer bound */
-            ret = OK;
-          }
-        else
-          {
-            int ifindex;
+        {
+          FAR struct net_driver_s *dev;
 
-            /* Get the interface index corresponding to the interface name */
+          /* Check if we are are unbinding the socket */
 
-            ifindex = netdev_nametoindex(value);
-            if (ifindex >= 0)
-              {
-                DEBUGASSERT(ifindex > 0 && ifindex <= MAX_IFINDEX);
-                conn->boundto = ifindex;
-                ret = OK;
-              }
-            else
-              {
-                ret = ifindex;
-              }
-          }
+          if (value == NULL || value_len == 0 ||
+             (value_len > 0 && ((FAR char *)value)[0] == 0))
+            {
+              /* Just report success if the socket is not bound to an
+               * interface.
+               */
 
+              if (conn->boundto != 0)
+                {
+                  /* Get the interface that we are bound do.  NULL would
+                   * indicate that the interface no longer exists for some
+                   * reason.
+                   */
+
+                  dev = netdev_findbyindex(conn->boundto);
+                  if (dev != NULL)
+                    {
+                      /* Clear the interface flag to unbind the device from
+                       * the socket.
+                       */
+
+                      IFF_CLR_BOUND(dev->d_flags);
+                    }
+
+                  conn->boundto = 0;  /* This interface is no longer bound */
+                }
+
+              ret = OK;
+            }
+
+          /* No, we are binding a socket to the interface. */
+
+          else
+            {
+              /* Find the interface device with this name */
+
+              dev = netdev_findbyname(value);
+              if (dev == NULL)
+                {
+                  ret = -ENODEV;
+                }
+
+              /* An interface may be bound only to one socket. */
+
+              else if (IFF_IS_BOUND(dev->d_flags))
+                {
+                  ret = -EBUSY;
+                }
+              else
+                {
+                  /* Bind the interface to a socket */
+
+                  IFF_SET_BOUND(dev->d_flags);
+
+                  /* Bind the socket to the interface */
+
+                  DEBUGASSERT(dev->d_ifindex > 0 &&
+                              dev->d_ifindex <= MAX_IFINDEX);
+                  conn->boundto = dev->d_ifindex;
+                  ret = OK;
+                }
+            }
+        }
         break;
 #endif