From: Nick Desaulniers <ndesaulniers@google.com>
To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de
Cc: clang-built-linux@googlegroups.com,
Nick Desaulniers <ndesaulniers@google.com>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Tri Vo <trong@android.com>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Rob Herring <robh@kernel.org>,
George Rimar <grimar@accesssoftek.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH v2] x86, realmode: explicitly set entry via command line
Date: Tue, 24 Sep 2019 12:33:08 -0700 [thread overview]
Message-ID: <20190924193310.132104-1-ndesaulniers@google.com> (raw)
In-Reply-To: <CAKwvOdmFqPSyeKn-0th_ca9B3QU63G__kEJ=X0tfjhE+1_p=FQ@mail.gmail.com>
Linking with ld.lld via $ make LD=ld.lld produces the warning:
ld.lld: warning: cannot find entry symbol _start; defaulting to 0x1000
Linking with ld.bfd shows the default entry is 0x1000:
$ readelf -h arch/x86/realmode/rm/realmode.elf | grep Entry
Entry point address: 0x1000
While ld.lld is being pedantic, just set the entry point explicitly,
instead of depending on the implicit default.
Link: https://github.com/ClangBuiltLinux/linux/issues/216
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
Changes V1 -> V2:
* Use command line flag, rather than linker script, as ld.bfd produces a
syntax error for `ENTRY(0x1000)` but is happy with `-e 0x1000`
arch/x86/realmode/rm/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index f60501a384f9..338a00c5257f 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -46,7 +46,7 @@ $(obj)/pasyms.h: $(REALMODE_OBJS) FORCE
targets += realmode.lds
$(obj)/realmode.lds: $(obj)/pasyms.h
-LDFLAGS_realmode.elf := -m elf_i386 --emit-relocs -T
+LDFLAGS_realmode.elf := -m elf_i386 --emit-relocs -e 0x1000 -T
CPPFLAGS_realmode.lds += -P -C -I$(objtree)/$(obj)
targets += realmode.elf
--
2.23.0.351.gc4317032e6-goog
next prev parent reply other threads:[~2019-09-24 19:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-23 22:24 [PATCH] x86, realmode: explicitly set ENTRY in linker script Nick Desaulniers
2019-09-24 17:30 ` Sedat Dilek
2019-09-24 18:24 ` Nathan Chancellor
2019-09-24 18:32 ` Nick Desaulniers
2019-09-24 19:33 ` Nick Desaulniers [this message]
2019-09-24 19:37 ` [PATCH v2] x86, realmode: explicitly set entry via command line Nick Desaulniers
2019-09-25 10:20 ` Borislav Petkov
2019-09-25 16:35 ` Nick Desaulniers
2019-09-25 17:02 ` Peter Smith
2019-09-25 17:10 ` Borislav Petkov
2019-09-25 18:09 ` [PATCH v3] x86, realmode: explicitly set entry via ENTRY in linker script Nick Desaulniers
2019-10-01 10:37 ` [tip: x86/boot] x86/realmode: Explicitly set entry point " tip-bot2 for Nick Desaulniers
2019-10-01 20:18 ` tip-bot2 for Nick Desaulniers
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