coreboot: x86: enable gc-sections
Garbage collected sections allow for trimming the size of the
binaries as well as allowing for not needing to config off
unused functions. To that end, on a rambi build the following
differences are observed:
$ diff -up \
<(readelf -l coreboot-builds/google_rambi/cbfs/fallback/ramstage.elf) \
<(readelf -l coreboot-builds/google_rambi_gc_sections/cbfs/fallback/ramstage.elf)
--- /dev/fd/63 2015-03-10 12:07:27.927985430 -0500
+++ /dev/fd/62 2015-03-10 12:07:27.927985430 -0500
@@ -6,9 +6,9 @@ There are 4 program headers, starting at
Program Headers:
Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg
Align
LOAD 0x001000 0x00000000 0x00000000 0x00040 0x00040 RWE 0
- LOAD 0x001040 0x00000040 0x00000040 0x34560 0x34560 RWE 0
- LOAD 0x0355a0 0x000345a0 0x000345a0 0x02578 0x02578 RWE 0
- LOAD 0x037b18 0x00036b18 0x00036b18 0x00000 0x0b560 0
+ LOAD 0x001040 0x00000040 0x00000040 0x2cbf8 0x2cbf8 RWE 0
+ LOAD 0x02dc38 0x0002cc38 0x0002cc38 0x02208 0x02208 RWE 0
+ LOAD 0x02fe40 0x0002ee40 0x0002ee40 0x00000 0x0a888 0
Section to Segment mapping:
Segment Sections...
$ diff -up \
<(readelf -l coreboot-builds/google_rambi/cbfs/fallback/romstage.elf) \
<(readelf -l coreboot-builds/google_rambi_gc_sections/cbfs/fallback/romstage.elf)
--- /dev/fd/63 2015-03-10 12:08:16.855985880 -0500
+++ /dev/fd/62 2015-03-10 12:08:16.851985880 -0500
@@ -5,8 +5,8 @@ There are 1 program headers, starting at
Program Headers:
Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg
Align
- LOAD 0x000060 0xfff20000 0xfff20000 0x08b81 0x08b81 R E
0x10
+ LOAD 0x000060 0xfff20000 0xfff20000 0x06300 0x06300 R E
0x10
Section to Segment mapping:
Segment Sections...
- 00 .rom .text
+ 00 .rom
The following warnings needed to be applied to CFLAGS_common because for
some reason gcc was miraculously emitting the warnings with the
unrelated *-sections options:
-Wno-unused-but-set-variable
Change-Id: I210784fdfc273ce4cb9927352cbd5a51be3c6929
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/8635
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
7 files changed