[build] Eliminate unused sections at link-time

Use -ffunction-sections, -fdata-sections, and --gc-sections to
automatically prune out any unreferenced sections.

This saves around 744 bytes (uncompressed) from the rtl8139.rom build.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

5 files changed, 24 insertions, 10 deletions

diff --git a/src/arch/i386/scripts/i386-kir.lds b/src/arch/i386/scripts/i386-kir.lds
index c19480f03..620bc2fe3 100644
--- a/src/arch/i386/scripts/i386-kir.lds
+++ b/src/arch/i386/scripts/i386-kir.lds
@@ -68,7 +68,8 @@ SECTIONS {
 
     .text16 : AT ( _text16_load_offset + __text16 ) {
 	__text16 = .;
-	*(.text.null_trap)
+	KEEP(*(.text.null_trap))
+	KEEP(*(.text.null_trap.*))
 	*(.text16)
 	*(.text16.*)
 	*(.text)
@@ -97,7 +98,7 @@ SECTIONS {
 	*(.data16.*)
 	*(.data)
 	*(.data.*)
-	*(SORT(.tbl.*))		/* Various tables.  See include/tables.h */
+	KEEP(*(SORT(.tbl.*)))	/* Various tables.  See include/tables.h */
 	_edata16_progbits = .;
     }
     .bss16 : AT ( _data16_load_offset + __bss16 ) {
@@ -129,8 +130,11 @@ SECTIONS {
 
     /DISCARD/ : {
 	*(.comment)
+	*(.comment.*)
 	*(.note)
+	*(.note.*)
 	*(.discard)
+	*(.discard.*)
     }
 
     /*
diff --git a/src/arch/i386/scripts/i386.lds b/src/arch/i386/scripts/i386.lds
index 610bfa16b..c5bc631fa 100644
--- a/src/arch/i386/scripts/i386.lds
+++ b/src/arch/i386/scripts/i386.lds
@@ -49,7 +49,8 @@ SECTIONS {
 
     .text16.early 0x0 : AT ( _text16_early_lma ) {
 	_text16 = .;
-	*(.text16.null)
+	KEEP(*(.text16.null))
+	KEEP(*(.text16.null.*))
 	. += 1;				/* Prevent NULL being valid */
 	*(.text16.early)
 	*(.text16.early.*)
@@ -98,7 +99,8 @@ SECTIONS {
 
     .textdata 0x0 : AT ( _textdata_lma ) {
 	_textdata = .;
-	*(.text.null_trap)
+	KEEP(*(.text.null_trap))
+	KEEP(*(.text.null_trap.*))
 	. += 1;				/* Prevent NULL being valid */
 	*(.text)
 	*(.text.*)
@@ -106,7 +108,7 @@ SECTIONS {
 	*(.rodata.*)
 	*(.data)
 	*(.data.*)
-	*(SORT(.tbl.*))		/* Various tables.  See include/tables.h */
+	KEEP(*(SORT(.tbl.*)))	/* Various tables.  See include/tables.h */
 	_mtextdata = .;
     } .bss.textdata (NOLOAD) : AT ( _end_lma ) {
 	*(.bss)
@@ -126,8 +128,8 @@ SECTIONS {
 
     .zinfo 0x0 : AT ( _zinfo_lma ) {
 	_zinfo = .;
-	*(.zinfo)
-	*(.zinfo.*)
+	KEEP(*(.zinfo))
+	KEEP(*(.zinfo.*))
 	_mzinfo = .;
     } .bss.zinfo (NOLOAD) : AT ( _end_lma ) {
 	_ezinfo = .;
@@ -143,6 +145,7 @@ SECTIONS {
     .weak 0x0 : AT ( _end_lma ) {
 	_weak = .;
 	*(.weak)
+	*(.weak.*)
 	_eweak = .;
     }
     _assert = ASSERT ( ( _weak == _eweak ), ".weak is non-zero length" );
@@ -165,6 +168,7 @@ SECTIONS {
 	*(.einfo)
 	*(.einfo.*)
 	*(.discard)
+	*(.discard.*)
     }
 
     /*
diff --git a/src/arch/i386/scripts/linux.lds b/src/arch/i386/scripts/linux.lds
index 94b7b900e..654f68e30 100644
--- a/src/arch/i386/scripts/linux.lds
+++ b/src/arch/i386/scripts/linux.lds
@@ -51,7 +51,7 @@ SECTIONS {
 		_data = .;
 		*(.data)
 		*(.data.*)
-		*(SORT(.tbl.*))		/* Various tables.  See include/tables.h */
+		KEEP(*(SORT(.tbl.*)))
 		_edata = .;
 	}
 
@@ -77,6 +77,7 @@ SECTIONS {
 	.weak 0x0 : {
 		_weak = .;
 		*(.weak)
+		*(.weak.*)
 		_eweak = .;
 	}
 	_assert = ASSERT ( ( _weak == _eweak ), ".weak is non-zero length" );
@@ -97,5 +98,6 @@ SECTIONS {
 		*(.rel)
 		*(.rel.*)
 		*(.discard)
+		*(.discard.*)
 	}
 }
diff --git a/src/arch/x86/scripts/efi.lds b/src/arch/x86/scripts/efi.lds
index d9963ef3b..1a16c29bd 100644
--- a/src/arch/x86/scripts/efi.lds
+++ b/src/arch/x86/scripts/efi.lds
@@ -54,7 +54,7 @@ SECTIONS {
 	_data = .;
 	*(.data)
 	*(.data.*)
-	*(SORT(.tbl.*))		/* Various tables.  See include/tables.h */
+	KEEP(*(SORT(.tbl.*)))	/* Various tables.  See include/tables.h */
 	_edata = .;
     }
 
@@ -80,6 +80,7 @@ SECTIONS {
     .weak 0x0 : {
 	_weak = .;
 	*(.weak)
+	*(.weak.*)
 	_eweak = .;
     }
     _assert = ASSERT ( ( _weak == _eweak ), ".weak is non-zero length" );
@@ -102,5 +103,6 @@ SECTIONS {
 	*(.einfo)
 	*(.einfo.*)
 	*(.discard)
+	*(.discard.*)
     }
 }
diff --git a/src/arch/x86_64/scripts/linux.lds b/src/arch/x86_64/scripts/linux.lds
index 34eb3561b..3bcd7aa1b 100644
--- a/src/arch/x86_64/scripts/linux.lds
+++ b/src/arch/x86_64/scripts/linux.lds
@@ -51,7 +51,7 @@ SECTIONS {
 		_data = .;
 		*(.data)
 		*(.data.*)
-		*(SORT(.tbl.*))		/* Various tables.  See include/tables.h */
+		KEEP(*(SORT(.tbl.*)))
 		_edata = .;
 	}
 
@@ -77,6 +77,7 @@ SECTIONS {
 	.weak 0x0 : {
 		_weak = .;
 		*(.weak)
+		*(.weak.*)
 		_eweak = .;
 	}
 	_assert = ASSERT ( ( _weak == _eweak ), ".weak is non-zero length" );
@@ -97,5 +98,6 @@ SECTIONS {
 		*(.rel)
 		*(.rel.*)
 		*(.discard)
+		*(.discard.*)
 	}
 }