Initial commit

1 files changed, 76 insertions, 0 deletions

diff --git a/instructions.h b/instructions.h
new file mode 100644
index 0000000..9727137
--- /dev/null
+++ b/instructions.h
@@ -0,0 +1,76 @@
+#ifndef INSTRUCTIONS_H
+#define INSTRUCTIONS_H
+
+// Prefixes
+// Prefix groups are mutually exclusive
+
+// Prefix group 1
+#define PREFIX_LOCK  0xf0
+#define PREFIX_REPNE 0xf2
+#define PREFIX_REPNZ PREFIX_REPNE
+#define PREFIX_REP   0xf3
+#define PREFIX_REPE  PREFIX_REP
+#define PREFIX_REPZ  PREFIX_REP
+
+// Prefix group 2
+#define PREFIX_OVERRIDE_SEGMENT_CS 0x2e
+#define PREFIX_OVERRIDE_SEGMENT_SS 0x36
+#define PREFIX_OVERRIDE_SEGMENT_DS 0x3e
+#define PREFIX_OVERRIDE_SEGMENT_ES 0x26
+#define PREFIX_OVERRIDE_SEGMENT_FS 0x64
+#define PREFIX_OVERRIDE_SEGMENT_GS 0x65
+#define PREFIX_BRANCH_NOT_TAKEN    PREFIX_OVERRIDE_SEGMENT_CS
+#define PREFIX_BRANCH_TAKEN        PREFIX_OVERRIDE_SEGMENT_DS
+
+// Prefix group 3
+#define PREFIX_OVERRIDE_OPSIZE 0x66
+
+// Prefix group 4
+#define PREFIX_OVERRIDE_ADDRESSSIZE 0x67
+
+// Instructions
+// Move double-word immediate
+#define MOVBI(reg, imm) (0xb0 + reg), (imm & 0xff)
+#define MOVWI(reg, imm)                                                        \
+  (0xb8 + reg), (imm & 0xff), ((imm >> 8) & 0xff), ((imm >> 16) & 0xff)
+#define MOVDI(reg, imm)                                                        \
+  (0xb8 + reg), (imm & 0xff), ((imm >> 8) & 0xff), ((imm >> 16) & 0xff),       \
+    ((imm >> 24) & 0xff)
+// TODO replace 0x48 with encoding,
+// | 0 1 0 0 | W R X B |
+//
+// 0 1 0 0 -- fixed pattern
+// W       -- Set to use 64-bit operands,
+// R       -- extension to MODRM.reg field, registers
+// X       -- extension to SIB.index field, 64-bit addressing
+// B       -- extension to MODRM.rm or SIB.base field, 64-bit addressing
+#define MOVABS(reg, imm) 0x48, MOVD(reg, imm)
+#define MOVQ(reg, imm)   0x48, 89 c8
+
+#define ADD
+#define CALL
+#define CMP
+#define DEC
+#define DIV
+#define HLT
+#define IDIV
+#define IMUL
+#define INC
+#define INT
+#define INTO
+#define IRET
+#define JNZ
+#define JMP
+#define LEA
+#define POP
+#define PUSH
+#define RET
+#define RETN
+#define SUB
+#define XOR
+
+#define SYSCALL 0x0f, 0x05
+
+#define REX(mode) (0b01000000 | mode)
+
+#endif