esp32: Provision to redirect .bss to external ram through linker fragments

Include external ram section in the linker template to process it
through linker script generation mechanism. This enables redirection of .bss section to external memory using linker fragments

libnet80211, libpp, libbt, liblwip: Redirect .bss through fragments

components/esp32/ld/esp32.extram.bss.ld

@@ -1,18 +0,0 @@
-/* This section is only included if CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
-   is set, to link some sections to BSS in PSRAM */
-
-SECTIONS
-{
-   /* external memory bss, from any global variable with EXT_RAM_ATTR attribute*/
-  .ext_ram.bss (NOLOAD) :
-  {
-    _ext_ram_bss_start = ABSOLUTE(.);
-    *(.ext_ram.bss*)
-    *libnet80211.a:(.dynsbss .sbss .sbss.* .gnu.linkonce.sb.* .scommon .sbss2.* .gnu.linkonce.sb2.* .dynbss .bss .bss.* .share.mem .gnu.linkonce.b.* COMMON)
-    *libpp.a:(.dynsbss .sbss .sbss.* .gnu.linkonce.sb.* .scommon .sbss2.* .gnu.linkonce.sb2.* .dynbss .bss .bss.* .share.mem .gnu.linkonce.b.* COMMON)
-    *liblwip.a:(.dynsbss .sbss .sbss.* .gnu.linkonce.sb.* .scommon .sbss2.* .gnu.linkonce.sb2.* .dynbss .bss .bss.* .share.mem .gnu.linkonce.b.* COMMON)
-    *libbt.a:(EXCLUDE_FILE (libbtdm_app.a) .dynsbss .sbss .sbss.* .gnu.linkonce.sb.* .scommon .sbss2.* .gnu.linkonce.sb2.* .dynbss .bss .bss.* .share.mem .gnu.linkonce.b.* COMMON)
-    . = ALIGN(4);
-    _ext_ram_bss_end = ABSOLUTE(.);
-  } > extern_ram_seg
-}

components/esp32/ld/esp32.project.ld.in

@@ -232,12 +232,22 @@ SECTIONS
     _noinit_end = ABSOLUTE(.);
   } > dram0_0_seg
 
+   /* external memory bss, from any global variable with EXT_RAM_ATTR attribute*/
+  .ext_ram.bss (NOLOAD) :
+  {
+    _ext_ram_bss_start = ABSOLUTE(.);
+
+    mapping[extern_ram]
+
+    . = ALIGN(4);
+    _ext_ram_bss_end = ABSOLUTE(.);
+  } > extern_ram_seg
+
   /* Shared RAM */
   .dram0.bss (NOLOAD) :
   {
     . = ALIGN (8);
     _bss_start = ABSOLUTE(.);
-    *(.ext_ram.bss*)
     _bt_bss_start = ABSOLUTE(.);
     *libbt.a:(.bss .bss.* COMMON)
     . = ALIGN (4);
@@ -253,18 +263,6 @@ SECTIONS
 
     mapping[dram0_bss]
 
-    *(.dynsbss)
-    *(.sbss)
-    *(.sbss.*)
-    *(.gnu.linkonce.sb.*)
-    *(.scommon)
-    *(.sbss2)
-    *(.sbss2.*)
-    *(.gnu.linkonce.sb2.*)
-    *(.dynbss)
-    *(.share.mem)
-    *(.gnu.linkonce.b.*)
-
     . = ALIGN (8);
     _bss_end = ABSOLUTE(.);
   } > dram0_0_seg

components/esp32/ld/esp32_fragments.lf

@@ -15,6 +15,18 @@ entries:
 entries:
     COMMON
 
+[sections:legacy_bss]
+entries:
+    .dynsbss
+    .sbss+
+    .gnu.linkonce.sb+
+    .scommon
+    .sbss2+
+    .gnu.linkonce.sb2+
+    .dynbss
+    .share.mem
+    .gnu.linkonce.b+
+
 [sections:rodata]
 entries:
     .rodata+
@@ -64,6 +76,10 @@ entries:
 entries:
     .iram.bss+
 
+[sections:extram_bss]
+entries:
+    .ext_ram.bss+
+
 [sections:dram]
 entries:
     .dram1+
@@ -87,6 +103,11 @@ entries:
     data -> dram0_data
     bss -> dram0_bss
     common -> dram0_bss
+    if SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY = y:
+        extram_bss -> extern_ram
+    else:
+        extram_bss -> dram0_bss
+    legacy_bss -> dram0_bss
     iram -> iram0_text
     iram_data -> iram0_data
     iram_bss -> iram0_bss
@@ -130,3 +151,8 @@ entries:
 [scheme:wifi_rx_iram]
 entries:
     wifi_rx_iram -> iram0_text
+
+[scheme:extram_bss]
+entries:
+    bss -> extern_ram
+    common -> extern_ram