From ffd60dd1efd6e86dae296219a986412413e65345 Mon Sep 17 00:00:00 2001
From: Omar Chebib <omar.chebib@espressif.com>
Date: Thu, 24 Feb 2022 15:24:11 +0800
Subject: [PATCH] (Xtensa) Build: add .xt.prop and .xt.lit to the compiled ELF
 file

Adding prop and lit sections to the ELF will let the debugger and the disassembler
have more info about data bytes present in the middle of the Xtensa
instructions, usually used for padding.
---
 .../subproject/main/ld/esp32/bootloader.ld    | 19 +++++++++++++++++++
 .../main/ld/esp32s2beta/bootloader.ld         | 19 +++++++++++++++++++
 components/esp32/ld/esp32.project.ld.in       | 19 +++++++++++++++++++
 .../esp32s2beta/ld/esp32s2beta.project.ld.in  | 19 +++++++++++++++++++
 4 files changed, 76 insertions(+)

diff --git a/components/bootloader/subproject/main/ld/esp32/bootloader.ld b/components/bootloader/subproject/main/ld/esp32/bootloader.ld
index 52aafe3f93..d8779c5ee4 100644
--- a/components/bootloader/subproject/main/ld/esp32/bootloader.ld
+++ b/components/bootloader/subproject/main/ld/esp32/bootloader.ld
@@ -177,4 +177,23 @@ SECTIONS
     _etext = .;
   } > iram_seg
 
+  /** This section will be used by the debugger and disassembler to get more information
+   * about raw data present in the code.
+   * Indeed, it may be required to add some padding at some points in the code
+   * in order to align a branch/jump destination on a particular bound.
+   * Padding these instructions will generate null bytes that shall be
+   * interpreted as data, and not code by the debugger or disassembler.
+   * This section will only be present in the ELF file, not in the final binary
+   * For more details, check GCC-212
+   */
+  .xt.prop 0 :
+  {
+    KEEP (*(.xt.prop .gnu.linkonce.prop.*))
+  }
+
+  .xt.lit 0 :
+  {
+    KEEP (*(.xt.lit .gnu.linkonce.p.*))
+  }
+
 }
diff --git a/components/bootloader/subproject/main/ld/esp32s2beta/bootloader.ld b/components/bootloader/subproject/main/ld/esp32s2beta/bootloader.ld
index c3b31ded30..5389637351 100644
--- a/components/bootloader/subproject/main/ld/esp32s2beta/bootloader.ld
+++ b/components/bootloader/subproject/main/ld/esp32s2beta/bootloader.ld
@@ -169,4 +169,23 @@ SECTIONS
     _etext = .;
   } > iram_seg
 
+  /** This section will be used by the debugger and disassembler to get more information
+   * about raw data present in the code.
+   * Indeed, it may be required to add some padding at some points in the code
+   * in order to align a branch/jump destination on a particular bound.
+   * Padding these instructions will generate null bytes that shall be
+   * interpreted as data, and not code by the debugger or disassembler.
+   * This section will only be present in the ELF file, not in the final binary
+   * For more details, check GCC-212
+   */
+  .xt.prop 0 :
+  {
+    KEEP (*(.xt.prop .gnu.linkonce.prop.*))
+  }
+
+  .xt.lit 0 :
+  {
+    KEEP (*(.xt.lit .gnu.linkonce.p.*))
+  }
+
 }
diff --git a/components/esp32/ld/esp32.project.ld.in b/components/esp32/ld/esp32.project.ld.in
index 85c22572bb..bb251a95c5 100644
--- a/components/esp32/ld/esp32.project.ld.in
+++ b/components/esp32/ld/esp32.project.ld.in
@@ -355,6 +355,25 @@ SECTIONS
     . = ALIGN (8);
     _heap_start = ABSOLUTE(.);
   } > dram0_0_seg
+
+  /** This section will be used by the debugger and disassembler to get more information
+    * about raw data present in the code.
+    * Indeed, it may be required to add some padding at some points in the code
+    * in order to align a branch/jump destination on a particular bound.
+    * Padding these instructions will generate null bytes that shall be
+    * interpreted as data, and not code by the debugger or disassembler.
+    * This section will only be present in the ELF file, not in the final binary
+    * For more details, check GCC-212
+    */
+  .xt.prop 0 :
+  {
+    KEEP (*(.xt.prop .gnu.linkonce.prop.*))
+  }
+
+  .xt.lit 0 :
+  {
+    KEEP (*(.xt.lit .gnu.linkonce.p.*))
+  }
 }
 
 ASSERT(((_iram_text_end - ORIGIN(iram0_0_seg)) <= LENGTH(iram0_0_seg)),
diff --git a/components/esp32s2beta/ld/esp32s2beta.project.ld.in b/components/esp32s2beta/ld/esp32s2beta.project.ld.in
index c379c85239..e3fec7fc64 100644
--- a/components/esp32s2beta/ld/esp32s2beta.project.ld.in
+++ b/components/esp32s2beta/ld/esp32s2beta.project.ld.in
@@ -338,4 +338,23 @@ SECTIONS
     */
     _flash_cache_start = ABSOLUTE(0);
   } >iram0_2_seg
+
+  /** This section will be used by the debugger and disassembler to get more information
+    * about raw data present in the code.
+    * Indeed, it may be required to add some padding at some points in the code
+    * in order to align a branch/jump destination on a particular bound.
+    * Padding these instructions will generate null bytes that shall be
+    * interpreted as data, and not code by the debugger or disassembler.
+    * This section will only be present in the ELF file, not in the final binary
+    * For more details, check GCC-212
+    */
+  .xt.prop 0 :
+  {
+    KEEP (*(.xt.prop .gnu.linkonce.prop.*))
+  }
+
+  .xt.lit 0 :
+  {
+    KEEP (*(.xt.lit .gnu.linkonce.p.*))
+  }
 }