Don't include eh_frame in the flashed firmware

Author: tact1m4n3

build-internals/build.zig

@@ -276,6 +276,9 @@ pub const LinkerScript = struct {
                 /// Place rodata in the first region tagged as ram.
                 ram,
             } = .flash,
+            /// Give .eh_frame and .eh_frame_hdr the status of other elf debug
+            /// sections (to not flash them to the device).
+            eh_frame_no_load: bool = true,
         },
     };
 };

port/espressif/esp/ld/esp32_c3/direct_boot_sections.ld

@@ -84,9 +84,13 @@ SECTIONS
   microzig_data_load_start = ORIGIN(DROM) + _irom_size + _drom_size;
   PROVIDE(__global_pointer$ = microzig_data_start + 0x800);
 
-  /DISCARD/ :
+  .eh_frame_hdr 0 (INFO) :
   {
-    *(.eh_frame_hdr)
-    *(.eh_frame)
+    KEEP(*(.eh_frame_hdr))
+  }
+
+  .eh_frame 0 (INFO) :
+  {
+    KEEP(*(.eh_frame))
   }
 }

port/espressif/esp/ld/esp32_c3/flashless_sections.ld

@@ -59,9 +59,13 @@ SECTIONS
 
   PROVIDE(__global_pointer$ = microzig_data_start + 0x800);
 
-  /DISCARD/ :
+  .eh_frame_hdr 0 (INFO) :
   {
-    *(.eh_frame_hdr)
-    *(.eh_frame)
+    KEEP(*(.eh_frame_hdr))
+  }
+
+  .eh_frame 0 (INFO) :
+  {
+    KEEP(*(.eh_frame))
   }
 }

port/espressif/esp/ld/esp32_c3/image_boot_sections.ld

@@ -116,9 +116,13 @@ SECTIONS
 
   PROVIDE(__global_pointer$ = microzig_data_start + 0x800);
 
-  /DISCARD/ :
+  .eh_frame_hdr 0 (INFO) :
   {
-    *(.eh_frame_hdr)
-    *(.eh_frame)
+    KEEP(*(.eh_frame_hdr))
+  }
+
+  .eh_frame 0 (INFO) :
+  {
+    KEEP(*(.eh_frame))
   }
 }

tools/generate_linker_script.zig

@@ -268,6 +268,22 @@ pub fn main(init: std.process.Init) !void {
             , .{flash_region_name});
         }
 
+        if (options.eh_frame_no_load) {
+            try writer.interface.writeAll(
+                \\
+                \\  .eh_frame_hdr 0 (INFO) :
+                \\  {
+                \\    KEEP(*(.eh_frame_hdr))
+                \\  }
+                \\
+                \\  .eh_frame 0 (INFO) :
+                \\  {
+                \\    KEEP(*(.eh_frame))
+                \\  }
+                \\
+            );
+        }
+
         try writer.interface.writeAll(
             \\
             \\  microzig_data_load_start = LOADADDR(.data);