diff --git a/src/arch/sparc.c b/src/arch/sparc.c
index d550e8f..c81dc85 100644
--- a/src/arch/sparc.c
+++ b/src/arch/sparc.c
@@ -55,5 +55,5 @@ ArchPlugin arch_plugin =
 	_sparc_registers,
 	_sparc_instructions,
 	_sparc_write,
-	NULL
+	_sparc_decode
 };
diff --git a/src/arch/sparc.h b/src/arch/sparc.h
index e0d4910..fac14bf 100644
--- a/src/arch/sparc.h
+++ b/src/arch/sparc.h
@@ -22,12 +22,45 @@
 /* private */
 /* prototypes */
 /* plug-in */
+static int _sparc_decode(ArchPlugin * plugin, ArchInstructionCall * call);
 static int _sparc_write(ArchPlugin * plugin, ArchInstruction * instruction,
 		ArchInstructionCall * call);
 
 
 /* functions */
 /* plug-in */
+/* sparc_decode */
+static int _sparc_decode(ArchPlugin * plugin, ArchInstructionCall * call)
+{
+	ArchPluginHelper * helper = plugin->helper;
+	uint32_t u32;
+	uint32_t opcode;
+	ArchInstruction * ai;
+
+	if(helper->read(helper->arch, &u32, sizeof(u32)) != sizeof(u32))
+		return -1;
+	u32 = _htob32(u32);
+	if((u32 & 0xc0000000) == 0xc0000000) /* load store */
+		opcode = u32 & (0xc0000000 | (0xf << 19) | (0x1 << 13));
+	else if((u32 & 0xc1c00000) == 0x01000000) /* sethi */
+		opcode = u32 & (0x7 << 22);
+	else if((u32 & 0xc0000000) == 0x80000000) /* integer arithmetic */
+		opcode = u32 & (0x80000000 | (0x1f << 19) | (0x1 << 13));
+	else if((u32 & 0xc1c00000) == 0x00800000) /* branch */
+#if 0 /* FIXME figure what's wrong */
+		opcode = u32 & (0x00800000 | (0xf << 25) | (0x3 << 2));
+#else
+		opcode = u32 & (0x00800000 | (0xf << 25));
+#endif
+	else
+		return -1;
+	if((ai = helper->get_instruction_by_opcode(helper->arch, 32, opcode))
+			== NULL)
+		return -1;
+	return 0;
+}
+
+
 /* sparc_write */
 static int _write_branch(ArchInstruction * instruction,
 		ArchInstructionCall * call, uint32_t * opcode);
diff --git a/src/arch/sparc.ins b/src/arch/sparc.ins
index 8c570aa..74ae5b7 100644
--- a/src/arch/sparc.ins
+++ b/src/arch/sparc.ins
@@ -38,7 +38,7 @@
 #define bgeu		0xd
 #define bcc		bgeu
 /* flags */
-#define OPCBF		(4 << AOD_SIZE)
+#define OPCBF		(32 << AOD_SIZE)
 /* helpers */
 #define OPCB(opcode)	(opcode << 25 | 0x2 << 22)
 #define OPCB_U22	AO_IMMEDIATE(0, 21, 0)
@@ -70,8 +70,8 @@
 #define udivcc		(0x10 | udiv)
 #define sdivcc		(0x10 | sdiv)
 /* flags */
-#define OPIA1F		(4 << AOD_SIZE)
-#define OPIA2F		(4 << AOD_SIZE)
+#define OPIA1F		(32 << AOD_SIZE)
+#define OPIA2F		(32 << AOD_SIZE)
 /* registers */
 #define OPIA_RS1	AO_REGISTER(0, 32, 0)
 #define OPIA_RS2	AO_REGISTER(0, 32, 0)
@@ -94,8 +94,8 @@
 #define ldsb		0x9
 #define ldsh		0xa
 /* flags */
-#define OPLS1F		(4 << AOD_SIZE)
-#define OPLS2F		(4 << AOD_SIZE)
+#define OPLS1F		(32 << AOD_SIZE)
+#define OPLS2F		(32 << AOD_SIZE)
 /* registers */
 #define OPLS_RS1	AO_DREGISTER(0, 12, 32, 0)
 #define OPLS_RS1D	AO_DREGISTER(0, 0, 32, 0)
@@ -108,7 +108,7 @@
 /* opcodes */
 #define sethi		0x4
 /* flags */
-#define OPSHF		(4 << AOD_SIZE)
+#define OPSHF		(32 << AOD_SIZE)
 /* helpers */
 #define OPSH(opcode)	(opcode << 22)
 #define OPSH_U21	AO_IMMEDIATE(0, 32, 0)
diff --git a/src/arch/sparc64.c b/src/arch/sparc64.c
index 599d489..c775af6 100644
--- a/src/arch/sparc64.c
+++ b/src/arch/sparc64.c
@@ -55,5 +55,5 @@ ArchPlugin arch_plugin =
 	_sparc64_registers,
 	_sparc64_instructions,
 	_sparc_write,
-	NULL
+	_sparc_decode
 };