esp_common: Correctly disable ".bss segment placed in external memory…

…" for ESP32-S2 & ESP32-S3

Support for this feature is still pending.

As reported by #6162

components/esp_common/Kconfig.spiram.common

@@ -92,7 +92,7 @@ config SPIRAM_MALLOC_RESERVE_INTERNAL
 config SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
     bool "Allow .bss segment placed in external memory"
     default n
-    depends on SPIRAM
+    depends on SPIRAM && IDF_TARGET_ESP32 # TODO ESP32-S2 IDFGH-4320, ESP32-S3 IDF-1974
     select ESP_ALLOW_BSS_SEG_EXTERNAL_MEMORY
     help
         If enabled, variables with EXT_RAM_ATTR attribute will be placed in SPIRAM instead of internal DRAM.

docs/en/api-guides/external-ram.rst

@@ -31,10 +31,12 @@ Configuring External RAM
 
 ESP-IDF fully supports the use of external memory in applications. Once the external RAM is initialized at startup, ESP-IDF can be configured to handle it in several ways:
 
- * :ref:`external_ram_config_memory_map`
- * :ref:`external_ram_config_capability_allocator`
- * :ref:`external_ram_config_malloc` (default)
- * :ref:`external_ram_config_bss`
+.. list::
+
+    * :ref:`external_ram_config_memory_map`
+    * :ref:`external_ram_config_capability_allocator`
+    * :ref:`external_ram_config_malloc` (default)
+    :esp32: * :ref:`external_ram_config_bss`
 
 .. _external_ram_config_memory_map:
 
@@ -83,23 +85,24 @@ If a suitable block of preferred internal/external memory is not available, the
 
 Because some buffers can only be allocated in internal memory, a second configuration item :ref:`CONFIG_SPIRAM_MALLOC_RESERVE_INTERNAL` defines a pool of internal memory which is reserved for *only* explicitly internal allocations (such as memory for DMA use). Regular ``malloc()`` will not allocate from this pool. The :ref:`MALLOC_CAP_DMA <dma-capable-memory>` and ``MALLOC_CAP_INTERNAL`` flags can be used to allocate memory from this pool.
 
-.. _external_ram_config_bss:
+.. only:: esp32
 
+    .. _external_ram_config_bss:
 
-Allow .bss segment placed in external memory
---------------------------------------------
+    Allow .bss segment placed in external memory
+    --------------------------------------------
 
-Enable this option by checking :ref:`CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY`. This configuration setting is independent of the other three.
+    Enable this option by checking :ref:`CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY`. This configuration setting is independent of the other three.
 
-If enabled, a region of the address space starting from 0x3F800000 will be used to store zero-initialized data (BSS segment) from the lwIP, net80211, libpp, and bluedroid ESP-IDF libraries.
+    If enabled, a region of the address space starting from 0x3F800000 will be used to store zero-initialized data (BSS segment) from the lwIP, net80211, libpp, and bluedroid ESP-IDF libraries.
 
-Additional data can be moved from the internal BSS segment to external RAM by applying the macro ``EXT_RAM_ATTR`` to any static declaration (which is not initialized to a non-zero value).
+    Additional data can be moved from the internal BSS segment to external RAM by applying the macro ``EXT_RAM_ATTR`` to any static declaration (which is not initialized to a non-zero value).
 
-It is also possible to place the BSS section of a component or a library to external RAM using linker fragment scheme ``extram_bss``.
+    It is also possible to place the BSS section of a component or a library to external RAM using linker fragment scheme ``extram_bss``.
 
-This option reduces the internal static memory used by the BSS segment.
+    This option reduces the internal static memory used by the BSS segment.
 
-Remaining external RAM can also be added to the capability heap allocator using the method shown above.
+    Remaining external RAM can also be added to the capability heap allocator using the method shown above.
 
 
 Restrictions

docs/zh_CN/api-guides/external-ram.rst

@@ -31,10 +31,12 @@
 
 ESP-IDF 完全支持将外部存储器集成到您的应用程序中。在启动并完成片外 RAM 初始化后，可以将 ESP-IDF 配置为以多种方式处理片外 RAM：
 
- * :ref:`external_ram_config_memory_map`
- * :ref:`external_ram_config_capability_allocator`
- * :ref:`external_ram_config_malloc` （默认）
- * :ref:`external_ram_config_bss`
+.. list::
+
+    * :ref:`external_ram_config_memory_map`
+    * :ref:`external_ram_config_capability_allocator`
+    * :ref:`external_ram_config_malloc` （默认）
+    :esp32: * :ref:`external_ram_config_bss`
 
 .. _external_ram_config_memory_map:
 
@@ -83,23 +85,25 @@ ESP-IDF 启动过程中，片外 RAM 被映射到以 0x3F800000 起始的数据
 
 由于有些 Buffer 仅可在内部存储器中分配，因此需要使用第二个配置项 :ref:`CONFIG_SPIRAM_MALLOC_RESERVE_INTERNAL` 定义一个内部存储池，仅限显式的内部存储器分配使用（例如用于 DMA 的存储器）。常规 ``malloc()`` 将不会从该池中分配，但可以使用 :ref:`MALLOC_CAP_DMA <dma-capable-memory>` 和 ``MALLOC_CAP_INTERNAL`` 旗标从该池中分配存储器。
 
-.. _external_ram_config_bss:
+.. only:: esp32
+
+    .. _external_ram_config_bss:
 
 
-允许 .bss 段放入片外存储器
------------------------------
+    允许 .bss 段放入片外存储器
+    -----------------------------
 
-通过检查 :ref:`CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY` 启用该选项，此选项配置与上面三个选项互不影响。
+    通过检查 :ref:`CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY` 启用该选项，此选项配置与上面三个选项互不影响。
 
-启用该选项后，从 0x3F800000 起始的地址空间将用于存储来自 lwip、net80211、libpp 和 bluedroid ESP-IDF 库中零初始化的数据（BSS 段）。
+    启用该选项后，从 0x3F800000 起始的地址空间将用于存储来自 lwip、net80211、libpp 和 bluedroid ESP-IDF 库中零初始化的数据（BSS 段）。
 
-``EXT_RAM_ATTR`` 宏应用于任何静态声明（未初始化为非零值）之后，可以将附加数据从内部 BSS 段移到片外 RAM。
+    ``EXT_RAM_ATTR`` 宏应用于任何静态声明（未初始化为非零值）之后，可以将附加数据从内部 BSS 段移到片外 RAM。
 
-也可以使用链接器片段方案 ``extram_bss`` 将组件或库的 BSS 段放到片外 RAM 中。
+    也可以使用链接器片段方案 ``extram_bss`` 将组件或库的 BSS 段放到片外 RAM 中。
 
-启用此选项可以减少 BSS 段占用的内部静态存储。
+    启用此选项可以减少 BSS 段占用的内部静态存储。
 
-剩余的片外 RAM 也可以通过上述方法添加到堆分配器中。
+    剩余的片外 RAM 也可以通过上述方法添加到堆分配器中。
 
 片外 RAM 使用限制
 ===================
@@ -114,8 +118,11 @@ ESP-IDF 启动过程中，片外 RAM 被映射到以 0x3F800000 起始的数据
 
  * 片外 RAM 不可用作任务堆栈存储器。因此 :cpp:func:`xTaskCreate` 及类似函数将始终为堆栈和任务 TCB 分配片上储存器，而 :cpp:func:`xTaskCreateStatic` 类型的函数将检查传递的 Buffer 是否属于片上存储器。
 
- * 默认情况下，片外 RAM 初始化失败将终止 ESP-IDF 启动。如果想禁用此功能，可启用 :ref:`CONFIG_SPIRAM_IGNORE_NOTFOUND` 配置选项。如果启用 :ref:`CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY`，:ref:`CONFIG_SPIRAM_IGNORE_NOTFOUND` 选项将不能使用，这是因为在链接时，链接器已经向片外 RAM 分配符号。
+ * 默认情况下，片外 RAM 初始化失败将终止 ESP-IDF 启动。如果想禁用此功能，可启用 :ref:`CONFIG_SPIRAM_IGNORE_NOTFOUND` 配置选项。
+
+.. only:: esp32
 
+    如果启用 :ref:`CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY`，:ref:`CONFIG_SPIRAM_IGNORE_NOTFOUND` 选项将不能使用，这是因为在链接时，链接器已经向片外 RAM 分配符号。
 
 .. only:: esp32