build: Fix GRUB i386-pc build with Ubuntu gcc

With recent versions of gcc on Ubuntu a very large lzma_decompress.img file is
output. (e.g. 134479600 bytes instead of 2864.) This causes grub-mkimage to
fail with: "error: Decompressor is too big."

This seems to be caused by a section .note.gnu.property that is placed at an
offset such that objcopy needs to pad the img file with zeros.

This issue is present on:
Ubuntu 19.10 with gcc (Ubuntu 8.3.0-26ubuntu1~19.10) 8.3.0
Ubuntu 19.10 with gcc (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008

This issue is not present on:
Ubuntu 19.10 with gcc (Ubuntu 7.5.0-3ubuntu1~19.10) 7.5.0
RHEL 8.0 with gcc 8.3.1 20190507 (Red Hat 8.3.1-4)

The issue can be fixed by removing the section using objcopy as shown in
this patch.

Signed-off-by: Simon Hardy <simon.hardy@itdev.co.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

diff --git a/gentpl.py b/gentpl.py
index 387588c05899a549b5aabff2e731909eaee53ede..c86550d4f9e502fb7a0ce62f5a2ece6ee054c417 100644 (file)
--- a/gentpl.py
+++ b/gentpl.py
@@ -766,7 +766,7 @@ def image(defn, platform):
 if test x$(TARGET_APPLE_LINKER) = x1; then \
   $(MACHO2IMG) $< $@; \
 else \
-  $(TARGET_OBJCOPY) $(""" + cname(defn) + """_OBJCOPYFLAGS) --strip-unneeded -R .note -R .comment -R .note.gnu.build-id -R .MIPS.abiflags -R .reginfo -R .rel.dyn -R .note.gnu.gold-version -R .ARM.exidx $< $@; \
+  $(TARGET_OBJCOPY) $(""" + cname(defn) + """_OBJCOPYFLAGS) --strip-unneeded -R .note -R .comment -R .note.gnu.build-id -R .MIPS.abiflags -R .reginfo -R .rel.dyn -R .note.gnu.gold-version -R .note.gnu.property -R .ARM.exidx $< $@; \
 fi
 """)