From 599480418116fb02b14dd3d8fa991c46de4b9f31 Mon Sep 17 00:00:00 2001
From: Daniel Beer <daniel@tortek.co.nz>
Date: Tue, 10 Aug 2010 13:27:35 +1200
Subject: [PATCH] dis: decode extended double-operand instructions.

---
 cproc_util.c |  2 ++
 dis.c        | 90 ++++++++++++++++++++++++++++++++++++++--------------
 dis.h        | 23 ++++++++++++--
 3 files changed, 90 insertions(+), 25 deletions(-)

diff --git a/cproc_util.c b/cproc_util.c
index 4a4432a..f911549 100644
--- a/cproc_util.c
+++ b/cproc_util.c
@@ -136,6 +136,8 @@ static int dis_format(stab_t stab, char *buf, int max_len,
 		suffix = ".B";
 	else if (insn->dsize == MSP430_DSIZE_AWORD)
 		suffix = ".A";
+	else if (insn->dsize == MSP430_DSIZE_UNKNOWN)
+		suffix = ".?";
 
 	len = snprintf(buf + total, max_len - total,
 		       "\x1b[36m%s%s\x1b[0m", opname, suffix);
diff --git a/dis.c b/dis.c
index 607ef84..a696a37 100644
--- a/dis.c
+++ b/dis.c
@@ -26,6 +26,7 @@
 #include "util.h"
 
 #define ALL_ONES               0xfffff
+#define EXTENSION_BIT          0x20000
 
 /**********************************************************************/
 /* Disassembler
@@ -402,43 +403,72 @@ int dis_decode(const uint8_t *code, address_t offset, address_t len,
 	       struct msp430_instruction *insn)
 {
 	uint16_t op;
+	uint16_t ex_word = 0;
 	int ret;
 	address_t ds_mask = ALL_ONES;
 
 	memset(insn, 0, sizeof(*insn));
+	insn->offset = offset;
 
+	/* Perform decoding */
 	if (len < 2)
 		return -1;
-
-	insn->offset = offset;
 	op = (code[1] << 8) | code[0];
 
-	if ((op & 0xf000) == 0x1000)
-		insn->itype = MSP430_ITYPE_SINGLE;
-	else if ((op & 0xff00) >= 0x2000 &&
-		 (op & 0xff00) < 0x4000)
-		insn->itype = MSP430_ITYPE_JUMP;
-	else if ((op & 0xf000) >= 0x4000)
-		insn->itype = MSP430_ITYPE_DOUBLE;
-	else
-		return -1;
+	if ((op & 0xf800) == 0x1800) {
+		ex_word = op;
+		code += 2;
+		offset += 2;
+		len -= 2;
 
-	switch (insn->itype) {
-	case MSP430_ITYPE_SINGLE:
-		ret = decode_single(code, offset, len, insn);
-		break;
+		if (len < 2)
+			return -1;
+		op = (code[1] << 8) | code[0];
 
-	case MSP430_ITYPE_DOUBLE:
-		ret = decode_double(code, offset, len, insn);
-		break;
+		if ((op & 0xff00) >= 0x4000) {
+			insn->itype = MSP430_ITYPE_DOUBLE;
+			ret = decode_double(code, offset, len, insn);
+			insn->op |= EXTENSION_BIT;
+		} else {
+			return -1;
+		}
 
-	case MSP430_ITYPE_JUMP:
-		ret = decode_jump(code, offset, len, insn);
-		break;
+		if (insn->dst_mode == MSP430_AMODE_REGISTER &&
+		    (insn->itype == MSP430_ITYPE_SINGLE ||
+		     insn->src_mode == MSP430_AMODE_REGISTER)) {
+			insn->zero_carry = (ex_word >> 8) & 1;
+			insn->rep_register = (ex_word >> 7) & 1;
+			insn->rep_index = ex_word & 0xf;
+		} else {
+			insn->dst_addr |= (ex_word & 0xf) << 16;
+			insn->src_addr |= ((ex_word >> 6) & 0xf) << 16;
+		}
 
-	default: break;
+		if (ex_word & 0x40) {
+			if (insn->dsize == MSP430_DSIZE_BYTE)
+				insn->dsize = MSP430_DSIZE_AWORD;
+			else
+				insn->dsize = MSP430_DSIZE_UNKNOWN;
+		}
+	} else {
+		if ((op & 0xf000) == 0x1000) {
+			insn->itype = MSP430_ITYPE_SINGLE;
+			ret = decode_single(code, offset, len, insn);
+		} else if ((op & 0xff00) >= 0x2000 &&
+			   (op & 0xff00) < 0x4000) {
+			insn->itype = MSP430_ITYPE_JUMP;
+			ret = decode_jump(code, offset, len, insn);
+		} else if ((op & 0xf000) >= 0x4000) {
+			insn->itype = MSP430_ITYPE_DOUBLE;
+			ret = decode_double(code, offset, len, insn);
+		} else {
+			return -1;
+		}
 	}
 
+	/* Interpret "emulated" instructions, constant generation, and
+	 * trim data sizes.
+	 */
 	find_cgens(insn);
 	find_emulated_ops(insn);
 
@@ -517,7 +547,21 @@ static const struct {
 	{MSP430_OP_SETC,        "SETC"},
 	{MSP430_OP_SETN,        "SETN"},
 	{MSP430_OP_SETZ,        "SETZ"},
-	{MSP430_OP_TST,         "TST"}
+	{MSP430_OP_TST,         "TST"},
+
+	/* MSP430X double operand */
+	{MSP430_OP_MOVX,        "MOVX"},
+	{MSP430_OP_ADDX,        "ADDX"},
+	{MSP430_OP_ADDCX,       "ADDCX"},
+	{MSP430_OP_SUBCX,       "SUBCX"},
+	{MSP430_OP_SUBX,        "SUBX"},
+	{MSP430_OP_CMPX,        "CMPX"},
+	{MSP430_OP_DADDX,       "DADDX"},
+	{MSP430_OP_BITX,        "BITX"},
+	{MSP430_OP_BICX,        "BICX"},
+	{MSP430_OP_BISX,        "BISX"},
+	{MSP430_OP_XORX,        "XORX"},
+	{MSP430_OP_ANDX,        "ANDX"}
 };
 
 /* Return the mnemonic for an operation, if possible. */
diff --git a/dis.h b/dis.h
index f8aa4f3..e16d498 100644
--- a/dis.h
+++ b/dis.h
@@ -109,7 +109,8 @@ typedef enum {
 typedef enum {
 	MSP430_DSIZE_BYTE,
 	MSP430_DSIZE_WORD,
-	MSP430_DSIZE_AWORD
+	MSP430_DSIZE_AWORD,
+	MSP430_DSIZE_UNKNOWN
 } msp430_dsize_t;
 
 /* MSP430 operations.
@@ -182,7 +183,21 @@ typedef enum {
 	MSP430_OP_SETC          = 0x10014,
 	MSP430_OP_SETN          = 0x10015,
 	MSP430_OP_SETZ          = 0x10016,
-	MSP430_OP_TST           = 0x10017
+	MSP430_OP_TST           = 0x10017,
+
+	/* MSP430X double operand */
+	MSP430_OP_MOVX          = 0x24000,
+	MSP430_OP_ADDX          = 0x25000,
+	MSP430_OP_ADDCX         = 0x26000,
+	MSP430_OP_SUBCX         = 0x27000,
+	MSP430_OP_SUBX          = 0x28000,
+	MSP430_OP_CMPX          = 0x29000,
+	MSP430_OP_DADDX         = 0x2A000,
+	MSP430_OP_BITX          = 0x2B000,
+	MSP430_OP_BICX          = 0x2C000,
+	MSP430_OP_BISX          = 0x2D000,
+	MSP430_OP_XORX          = 0x2E000,
+	MSP430_OP_ANDX          = 0x2F000
 } msp430_op_t;
 
 /* This represents a decoded instruction. All decoded addresses are
@@ -205,6 +220,10 @@ struct msp430_instruction {
 	msp430_amode_t          dst_mode;
 	address_t		dst_addr;
 	msp430_reg_t            dst_reg;
+
+	int			rep_index;
+	int			rep_register;
+	int			zero_carry;
 };
 
 /* Decode a single instruction.