diff --git a/src/arm/decompiler.h b/src/arm/decompiler.h
index 59c47887b..40c446990 100644
--- a/src/arm/decompiler.h
+++ b/src/arm/decompiler.h
@@ -3,8 +3,80 @@
 
 #include <stdint.h>
 
+union ARMOperand {
+	uint8_t reg;
+	int32_t immediate;
+};
+
+struct ARMMemoryAccess {
+	uint8_t baseRegister;
+	union ARMOperand offset;
+};
+
+enum ARMOperandFormat {
+	ARM_OPERAND_NONE =               0x00000000,
+	ARM_OPERAND_REGISTER_1 =         0x00000001,
+	ARM_OPERAND_IMMEDIATE_1 =        0x00000002,
+	ARM_OPERAND_MEMORY_REGISTER_1 =  0x00000005,
+	ARM_OPERAND_MEMORY_IMMEDIATE_1 = 0x00000006,
+	ARM_OPERAND_MEMORY_OFFSET_1 =    0x00000007,
+	ARM_OPERAND_AFFECTED_1 =         0x00000080,
+	ARM_OPERAND_MEMORY_POST_INCR_1 = 0x00000097,
+	ARM_OPERAND_MEMORY_PRE_INCR_1 =  0x000000A7,
+};
+
+enum ThumbMnemonic {
+	THUMB_MN_ILL = 0,
+	THUMB_MN_ADC,
+	THUMB_MN_ADD,
+	THUMB_MN_AND,
+	THUMB_MN_ASR,
+	THUMB_MN_B,
+	THUMB_MN_BIC,
+	THUMB_MN_BL,
+	THUMB_MN_BLH,
+	THUMB_MN_BX,
+	THUMB_MN_CMN,
+	THUMB_MN_CMP,
+	THUMB_MN_EOR,
+	THUMB_MN_LDMIA,
+	THUMB_MN_LDR,
+	THUMB_MN_LDRB,
+	THUMB_MN_LDRH,
+	THUMB_MN_LDRSB,
+	THUMB_MN_LDRSH,
+	THUMB_MN_LSL,
+	THUMB_MN_LSR,
+	THUMB_MN_MOV,
+	THUMB_MN_MUL,
+	THUMB_MN_MVN,
+	THUMB_MN_NEG,
+	THUMB_MN_ORR,
+	THUMB_MN_POP,
+	THUMB_MN_PUSH,
+	THUMB_MN_ROR,
+	THUMB_MN_SBC,
+	THUMB_MN_STMIA,
+	THUMB_MN_STR,
+	THUMB_MN_STRB,
+	THUMB_MN_STRH,
+	THUMB_MN_SUB,
+	THUMB_MN_SWI,
+	THUMB_MN_TST
+};
+
 struct ThumbInstructionInfo {
 	uint16_t opcode;
+	enum ThumbMnemonic mnemonic;
+	union ARMOperand op1;
+	union ARMOperand op2;
+	union ARMOperand op3;
+	struct ARMMemoryAccess memory;
+	int immediateFormat;
+	int operandFormat;
+	int branches;
+	int accessesMemory;
+	int accessesHighRegisters;
 };
 
 void ARMDecodeThumb(uint16_t opcode, struct ThumbInstructionInfo* info);