Fix ARCompact disassembly

ReverseLab · Oct 24, 2013 · 84481c5 · 84481c5
1 parent dd050b3
commit 84481c5
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Showing 5 changed files with 76 additions and 12 deletions.
diff --git a/libr/anal/p/anal_arc.c b/libr/anal/p/anal_arc.c
@@ -7,10 +7,12 @@
 #include <r_anal.h>
 
 static int arcompact_op(RAnal *anal, RAnalOp *op, ut64 addr, const ut8 *data, int len) {
-	/* ARCompact ISA */
 	const ut8 *b = (ut8 *)data;
+	ut8 subopcode = ((b[1]&0xf)>>2) << 1;
+	ut8 basecode = (b[3] & 0xf8) >> 3;
 	int lowbyte, highbyte;
 
+	/* ARCompact ISA */
 	lowbyte = anal->big_endian? 0: 1;
 	highbyte = anal->big_endian? 1: 0;
 
@@ -19,16 +21,76 @@ static int arcompact_op(RAnal *anal, RAnalOp *op, ut64 addr, const ut8 *data, in
 	} else {
 		op->length = 4;
 	}
-// XXX: compact instructions can be >4 !??
+// some ops are 6 and others are 8 byte length
 	op->fail = addr + 4;
-	ut8 basecode = (b[3] & 0xf8) >> 3;
-	ut8 subopcode = ((b[1]&0xf)>>2)<<1;
 	//eprintf ("----> ST %x\n", subopcode);
 	//eprintf ("BC = 0x%x\n", basecode);
 	if (!memcmp (b, "\x4a\x26\x00\x70", 4)) {
 		op->type = R_ANAL_OP_TYPE_NOP;
 		return 4;
 	}
+	/* ARCompact ISA */
+	op->fail = addr + 4;
+	switch (basecode) {
+	case 0x0:
+		 {
+			ut64 imm = ((((b[0] & 0xc0) >> 6) | (b[1] << 2)) << 11) |
+			((((b[2] & 0xfe) >> 1) | ((b[3] & 0x7) << 8)) << 1);
+			imm = addr + 8+ (b[3] * 4);
+			if (imm != 0) {
+				op->type = R_ANAL_OP_TYPE_CJMP;
+				op->jump = imm;
+			}
+		 }
+		break;
+	case 0x01:
+		op->type = R_ANAL_OP_TYPE_CJMP;
+		op->jump = 0;
+		break;
+	case 0x02:
+	case 0x03:
+	case 0x04:
+	case 0x05:
+	case 0x06:
+	case 0x07:
+	case 0x08:
+	case 0x09:
+	case 0x0a:
+	case 0x0b:
+		break;
+	default:
+		/* This is 16 bit instruction */
+		op->length = 2;
+		op->fail = addr + 2;
+		basecode = (b[1] & 0xf8) >> 3;
+		switch (basecode) {
+		case 0x0c:
+		case 0x0d:
+			op->type = R_ANAL_OP_TYPE_ADD;
+			break;
+		case 0x0e:
+			op->type = R_ANAL_OP_TYPE_MOV;
+			break;
+		case 0x1b:
+			op->type = R_ANAL_OP_TYPE_MOV;
+			break;
+		case 0x1c:
+			if (b[0] & 0x80)
+				op->type = R_ANAL_OP_TYPE_CMP;
+			else
+				op->type = R_ANAL_OP_TYPE_ADD;
+			break;
+		case 0x1d:
+		case 0x1e:
+		case 0x1f:
+			op->type = R_ANAL_OP_TYPE_CJMP;
+			op->jump = 0;
+			break;
+		default:
+			break;
+		}
+		break;
+	}
 	return op->length;
 }
 

diff --git a/libr/asm/p/asm_arc.c b/libr/asm/p/asm_arc.c
@@ -12,12 +12,12 @@
 
 static unsigned long Offset = 0;
 static char *buf_global = NULL;
-static unsigned char bytes[4];
+static unsigned char bytes[32];
 
 static int arc_buffer_read_memory (bfd_vma memaddr, bfd_byte *myaddr, unsigned int length, struct disassemble_info *info) {
 	int delta = (memaddr - Offset);
 	if (delta<0) return -1; // disable backward reads
-	if ((delta+length)>4) return -1;
+	if ((delta+length)>sizeof (bytes)) return -1;
 	memcpy (myaddr, bytes+delta, length);
 	return 0;
 }
@@ -59,7 +59,9 @@ static int disassemble(RAsm *a, RAsmOp *op, const ut8 *buf, int len) {
 	if (len<4) return -1;
 	buf_global = op->buf_asm;
 	Offset = a->pc;
-	memcpy (bytes, buf, 4); // TODO handle compact
+	if (len>sizeof (bytes))
+		len = sizeof (bytes);
+	memcpy (bytes, buf, len); // TODO handle compact
 
 	/* prepare disassembler */
 	memset (&disasm_obj,'\0', sizeof (struct disassemble_info));

diff --git a/libr/core/cmd_print.c b/libr/core/cmd_print.c
@@ -1249,7 +1249,7 @@ R_API void r_print_offset(RPrint *p, ut64 off, int invert, int opt) {
 			r_cons_printf ("%s%04x:%04x"Color_RESET,
 				k, s&0xFFFF, a&0xFFFF);
 		} else r_cons_printf ("%s0x%08"PFMT64x""Color_RESET, k, off);
-		r_cons_puts ("  ");
-	} else r_cons_printf ("0x%08"PFMT64x"  ", off);
+		r_cons_puts (" ");
+	} else r_cons_printf ("0x%08"PFMT64x" ", off);
 }
 
diff --git a/libr/core/config.c b/libr/core/config.c
@@ -603,7 +603,7 @@ r_config_set (cfg, "asm.arch", R_SYS_ARCH);
 	r_config_desc (cfg, "asm.stackptr", "Show stack pointer at disassembly");
 	r_config_set (cfg, "asm.dwarf", "false");
 	r_config_desc (cfg, "asm.dwarf", "Show dwarf comment at disassembly");
-	r_config_set_i (cfg, "asm.nbytes", 8);
+	r_config_set_i (cfg, "asm.nbytes", 6);
 	r_config_set (cfg, "asm.tabs", "false");
 	r_config_desc (cfg, "asm.nbytes", "Number of bytes for each opcode at disassembly");
 	r_config_set (cfg, "asm.pseudo", "false");  // DEPRECATED ???

diff --git a/libr/core/disasm.c b/libr/core/disasm.c
@@ -881,8 +881,8 @@ R_API int r_core_print_disasm(RPrint *p, RCore *core, ut64 addr, ut8 *buf, int l
 				pad[j] = '\0';
 			}
 			if (show_color)
-				r_cons_printf (" %s %s %s"Color_RESET, pad, str, extra);
-			else r_cons_printf (" %s %s %s", pad, str, extra);
+				r_cons_printf ("%s %s %s"Color_RESET, pad, str, extra);
+			else r_cons_printf ("%s %s %s", pad, str, extra);
 			free (str);
 		}