From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] scripts/decodecode: Fix decoding for AArch64 (arm64) instructions
Date: Thu, 28 Sep 2017 11:55:47 +0100 [thread overview]
Message-ID: <1506596147-23630-1-git-send-email-will.deacon@arm.com> (raw)
There are a couple of problems with the decodecode script and arm64:
1. AArch64 objdump refuses to disassemble .4byte directives as instructions,
insisting that they are data values and displaying them as:
a94153f3 .word 0xa94153f3 <-- trapping instruction
This is resolved by using the .inst directive instead.
2. Disassembly of branch instructions attempts to provide the target as
an offset from a symbol, e.g.:
0: 34000082 cbz w2, 10 <.text+0x10>
however this falls foul of the grep -v, which matches lines containing
".text" and ends up removing all branch instructions from the dump.
This patch resolves both issues by using the .inst directive for 4-byte
quantities on arm64 and stripping the resulting binaries (as is done on
arm already) to remove the mapping symbols.
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
scripts/decodecode | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/scripts/decodecode b/scripts/decodecode
index d8824f37acce..67214ec5b2cb 100755
--- a/scripts/decodecode
+++ b/scripts/decodecode
@@ -58,6 +58,14 @@ disas() {
${CROSS_COMPILE}strip $1.o
fi
+ if [ "$ARCH" = "arm64" ]; then
+ if [ $width -eq 4 ]; then
+ type=inst
+ fi
+
+ ${CROSS_COMPILE}strip $1.o
+ fi
+
${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $1.o | \
grep -v "/tmp\|Disassembly\|\.text\|^$" > $1.dis 2>&1
}
--
2.1.4
next reply other threads:[~2017-09-28 10:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-28 10:55 Will Deacon [this message]
2017-09-28 12:42 ` [PATCH] scripts/decodecode: Fix decoding for AArch64 (arm64) instructions Dave Martin
2017-09-28 14:14 ` Will Deacon
2017-09-28 14:37 ` Dave Martin
2017-09-28 18:01 ` Will Deacon
2017-09-29 10:07 ` Dave Martin
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