The objcopy option "--dump-section" isn't supported in binutils before
version 2.25, which are still supported by the Xen build system.

Avoid that by using the "-O binary" format together with
"--only-section". This requires to set the "alloc" section flag.

Fixes: 33411a11f848 ("Mini-OS: hide all symbols not exported via EXPORT_SYMBOLS()")
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 456aed0b..6c8df8b5 100644
--- a/Makefile
+++ b/Makefile
@@ -166,7 +166,9 @@ $(OBJ_DIR)/arch/x86/minios-x86%.lds:  arch/x86/minios-x86.lds.S
 
 $(OBJ_DIR)/$(TARGET)-kern.o: $(OBJS) arch_lib $(OBJ_DIR)/$(TARGET_ARCH_DIR)/minios-$(MINIOS_TARGET_ARCH).lds
 	$(LD) -r $(LDFLAGS) $(HEAD_OBJ) $(OBJS) $(LDARCHLIB) -o $@
-	$(OBJCOPY) --dump-section .export_symbol=$(OBJ_DIR)/syms $@
+	# The following would be neat, but isn't supported in binutils < 2.25
+	# $(OBJCOPY) --dump-section .export_symbol=$(OBJ_DIR)/syms $@
+	$(OBJCOPY) --set-section-flags .export_symbol=alloc -O binary --only-section=.export_symbol $@ $(OBJ_DIR)/syms
 	$(OBJCOPY) -w -G $(GLOBAL_PREFIX)* --keep-global-symbols=$(OBJ_DIR)/syms --remove-section=.export_symbol $@ $@
 
 $(OBJ_DIR)/$(TARGET): $(OBJ_DIR)/$(TARGET)-kern.o $(APP_O)
-- 
2.35.3

On 06/12/2023 4:17 pm, Juergen Gross wrote:
> The objcopy option "--dump-section" isn't supported in binutils before
> version 2.25, which are still supported by the Xen build system.
>
> Avoid that by using the "-O binary" format together with
> "--only-section". This requires to set the "alloc" section flag.
>
> Fixes: 33411a11f848 ("Mini-OS: hide all symbols not exported via EXPORT_SYMBOLS()")
> Signed-off-by: Juergen Gross <jgross@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

And FAOD, I'm taking this, plus a bump to the minios rev right now to
unbreak Gitlab CI, as it's been broken for 2 now.

~Andrew