Merge remote-tracking branch 'origin/emulator' into Assembler-G

This commit is contained in:
GDBWNV 2024-06-06 10:11:57 +01:00
commit b362f46d58
19 changed files with 986 additions and 68 deletions

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@ -1,8 +1,11 @@
#ifndef __A64INSTRUCTION__ #ifndef __A64INSTRUCTION__
#define __A64INSTRUCTION__ #define __A64INSTRUCTION__
#include "a64instruction_DPImmediate.h" #include "a64instruction_DPImmediate.h"
#include "a64instruction_DPRegister.h"
#include "a64instruction_Branch.h" #include "a64instruction_Branch.h"
#include "a64instruction_SingleTransfer.h" #include "a64instruction_SingleTransfer.h"
#include "a64instruction_Label.h"
#include "a64instruction_Directive.h"
// Define the types of instructions in subset of the AArch64 Instruction Set implemented. // Define the types of instructions in subset of the AArch64 Instruction Set implemented.
// Each type is defined by the format of the instruction's operand(s). // Each type is defined by the format of the instruction's operand(s).
@ -12,7 +15,9 @@ typedef enum {
a64inst_SINGLETRANSFER, a64inst_SINGLETRANSFER,
a64inst_LOADLITERAL, a64inst_LOADLITERAL,
a64inst_BRANCH, a64inst_BRANCH,
a64inst_HALT a64inst_HALT,
a64inst_LABEL,
a64inst_DIRECTIVE
} a64inst_type; } a64inst_type;
// Structure the holds the type and operand data of an instruction // Structure the holds the type and operand data of an instruction
@ -20,8 +25,11 @@ typedef struct {
a64inst_type type; a64inst_type type;
union { union {
a64inst_DPImmediateData DPImmediateData; a64inst_DPImmediateData DPImmediateData;
a64inst_DPRegisterData DPRegisterData;
a64inst_BranchData BranchData; a64inst_BranchData BranchData;
a64inst_SingleTransferData SingleTransferData; a64inst_SingleTransferData SingleTransferData;
a64inst_LabelData LabelData;
a64inst_DirectiveData DirectiveData;
} data; } data;
} a64inst_instruction; } a64inst_instruction;

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@ -4,8 +4,8 @@
typedef enum { typedef enum {
a64inst_UNCONDITIONAL = 0, a64inst_UNCONDITIONAL = 0,
a64inst_REGISTER = 1, a64inst_REGISTER = 3,
a64inst_CONDITIONAL = 2 a64inst_CONDITIONAL = 1
} a64inst_BranchType; } a64inst_BranchType;
typedef struct { typedef struct {

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@ -1,3 +1,6 @@
#ifndef __A64INSTRUCTION_DP__
#define __A64INSTRUCTION_DP__
// Denotes the type of arithmetic operations supported by the architecture // Denotes the type of arithmetic operations supported by the architecture
typedef enum { typedef enum {
a64inst_ADD = 0, a64inst_ADD = 0,
@ -5,3 +8,5 @@ typedef enum {
a64inst_SUB = 2, a64inst_SUB = 2,
a64inst_SUBS = 3 a64inst_SUBS = 3
} a64inst_arithmOp; } a64inst_arithmOp;
#endif

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@ -4,8 +4,8 @@
// Denotes the type of data processing operation // Denotes the type of data processing operation
typedef enum { typedef enum {
a64inst_DPR_ARITHMLOGIC, a64inst_DPR_ARITHMLOGIC = 0,
a64inst_DPR_MULTIPLY a64inst_DPR_MULTIPLY = 1
} a64inst_DPROpType; } a64inst_DPROpType;
// Denotes the logical operations supported by the architecture // Denotes the logical operations supported by the architecture
@ -27,10 +27,11 @@ typedef enum {
// Holds data specific to arithmetic/logic register data processing instructions // Holds data specific to arithmetic/logic register data processing instructions
typedef struct { typedef struct {
enum { enum {
a64inst_DPR_ARITHM = 0, a64inst_DPR_ARITHM = 1,
a64inst_DPR_LOGIC = 1 a64inst_DPR_LOGIC = 0
} type; } type;
a64inst_ShiftType shiftType; a64inst_ShiftType shiftType;
uint8_t shiftAmount;
bool negShiftedSrc2; // Guaranteed to be 0 for arithmetic instructions bool negShiftedSrc2; // Guaranteed to be 0 for arithmetic instructions
} a64inst_DPRegister_ArithmLogicData; } a64inst_DPRegister_ArithmLogicData;
@ -44,10 +45,7 @@ typedef struct {
typedef struct { typedef struct {
a64inst_regType regType; a64inst_regType regType;
a64inst_DPROpType DPROpType; a64inst_DPROpType DPROpType;
union { uint8_t processOp;
a64inst_logicOp logicOp;
a64inst_arithmOp arithmOp;
} processOpId;
a64inst_regSpecifier src2; a64inst_regSpecifier src2;
union { union {
a64inst_DPRegister_ArithmLogicData arithmLogicData; a64inst_DPRegister_ArithmLogicData arithmLogicData;

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@ -0,0 +1,5 @@
#include "global.h"
typedef struct {
dword value;
} a64inst_DirectiveData;

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@ -0,0 +1,3 @@
typedef struct {
char* label;
} a64inst_LabelData;

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@ -8,7 +8,7 @@ typedef uint8_t a64inst_regSpecifier;
// Denotes the type of register being referred to // Denotes the type of register being referred to
typedef enum { typedef enum {
a64inst_W = 0, a64inst_W = 0,
a64inst_R = 1 a64inst_X = 1
} a64inst_regType; } a64inst_regType;
#endif #endif

169
src/decode.c Normal file
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@ -0,0 +1,169 @@
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include "decode.h"
#include "emulator.h"
// Retrieve the bits between positions 'lsb' (inclusive) and 'msb' (exclusive) from a given word
// as a new zero-extended word.
static word getBits(word wrd, uint8_t lsb, uint8_t msb) {
// Ensure LSB and MSB are within range of word size, and in the correct order
assert(lsb < msb && msb <= WORD_BITS);
wrd &= ((dword) 1 << msb) - 1;
return wrd >> lsb;
}
// Given a binary word, return its internal representation as an a64instruction struct encoding the same
// information.
a64inst_instruction *decode(word wrd) {
a64inst_instruction *inst = malloc(sizeof(a64inst_instruction));
if (inst == NULL) {
fprintf(stderr, "Ran out of memory while attempting to decode an instruction!\n");
exit(1);
}
word typeId = getBits(wrd, TYPE_ID_LSB, TYPE_ID_MSB);
// Halt interpretation
if (wrd == HALT_WORD) {
inst->type = a64inst_HALT;
// Data Processing Immediate interpretation
} else if (typeId == DP_IMM_ID) {
inst->type = a64inst_DPIMMEDIATE;
inst->data.DPImmediateData.regType = getBits(wrd, DP_WIDTH_LSB, DP_WIDTH_MSB);
inst->data.DPImmediateData.processOp = getBits(wrd, DP_OP_LSB, DP_OP_MSB);
inst->data.DPImmediateData.dest = getBits(wrd, DP_DEST_LSB, DP_DEST_MSB);
switch(getBits(wrd, DP_IMM_OPTYPE_LSB, DP_IMM_OPTYPE_MSB)) {
case DP_IMM_OPTYPE_ARITHM:
inst->data.DPImmediateData.DPIOpType = a64inst_DPI_ARITHM;
inst->data.DPImmediateData.processOpData.arithmData.shiftImmediate = getBits(wrd, DP_IMM_ARITHM_SHIFTFLAG_LSB, DP_IMM_ARITHM_SHIFTFLAG_MSB);
inst->data.DPImmediateData.processOpData.arithmData.immediate = getBits(wrd, DP_IMM_ARITHM_IMMVAL_LSB, DP_IMM_ARITHM_IMMVAL_MSB);
inst->data.DPImmediateData.processOpData.arithmData.src = getBits(wrd, DP_IMM_ARITHM_DEST_LSB, DP_IMM_ARITHM_DEST_MSB);
break;
case DP_IMM_OPTYPE_WIDEMOV:
inst->data.DPImmediateData.DPIOpType = a64inst_DPI_WIDEMOV;
inst->data.DPImmediateData.processOpData.wideMovData.shiftScalar = getBits(wrd, DP_IMM_WIDEMOV_SHIFTSCALAR_LSB, DP_IMM_WIDEMOV_SHIFTSCALAR_MSB);
inst->data.DPImmediateData.processOpData.wideMovData.immediate = getBits(wrd, DP_IMM_WIDEMOV_IMMVAL_LSB, DP_IMM_WIDEMOV_IMMVAL_MSB);
break;
default:
fprintf(stderr, "Unknown immediate data processing operation type found!\n");
exit(1);
break;
}
} else if (typeId == BRANCH_ID) {
inst->type = a64inst_BRANCH;
word branchTypeFlag = getBits(wrd, BRANCH_TYPE_LSB, BRANCH_TYPE_MSB);
inst->data.BranchData.BranchType = branchTypeFlag;
switch (branchTypeFlag) {
case a64inst_UNCONDITIONAL:
inst->data.BranchData.processOpData.unconditionalData.unconditionalOffset = getBits(wrd, BRANCH_UNCONDITIONAL_OFFSET_LSB, BRANCH_UNCONDITIONAL_OFFSET_MSB);
break;
case a64inst_CONDITIONAL:
inst->data.BranchData.processOpData.conditionalData.offset = getBits(wrd, BRANCH_CONDITIONAL_OFFSET_LSB, BRANCH_CONDITIONAL_OFFSET_MSB);
word conditionFlag = getBits(wrd, BRANCH_CONDITIONAL_COND_LSB, BRANCH_CONDITIONAL_COND_MSB);
if(conditionFlag <= 1 || (conditionFlag >= 10 && conditionFlag <= 14)) {
inst->data.BranchData.processOpData.conditionalData.cond = conditionFlag;
} else {
fprintf(stderr, "Unknown condition detected!\n");
exit(1);
}
break;
case a64inst_REGISTER:
inst->data.BranchData.processOpData.registerData.src = getBits(wrd, BRANCH_REGISTER_SRC_LSB, BRANCH_REGISTER_SRC_MSB);
break;
default:
fprintf(stderr, "Undefined branch type detected!\n");
exit(1);
break;
}
// TODO: Some minor code duplication between DPR and DPI data interpretation
// Data Processing Register interpretation
} else if (getBits(wrd, DP_REG_LSB, DP_REG_MSB) == 1) {
inst->type = a64inst_DPREGISTER;
inst->data.DPRegisterData.regType = getBits(wrd, DP_WIDTH_LSB, DP_WIDTH_MSB);
inst->data.DPRegisterData.processOp = getBits(wrd, DP_OP_LSB, DP_OP_MSB);
inst->data.DPRegisterData.dest = getBits(wrd, DP_DEST_LSB, DP_DEST_MSB);
inst->data.DPRegisterData.src1 = getBits(wrd, DP_REG_SRC1_LSB, DP_REG_SRC1_MSB);
inst->data.DPRegisterData.src2 = getBits(wrd, DP_REG_SRC2_LSB, DP_REG_SRC2_MSB);
inst->data.DPRegisterData.DPROpType = getBits(wrd, DP_REG_OPTYPE_LSB, DP_REG_OPTYPE_MSB);
a64inst_DPRegister_ArithmLogicData *arithmLogicData = &inst->data.DPRegisterData.processOpData.arithmLogicData;
arithmLogicData->type = getBits(wrd, DP_REG_ARITHMLOGIC_ARITHMFLAG_LSB, DP_REG_ARITHMLOGIC_ARITHMFLAG_MSB);
arithmLogicData->shiftType = getBits(wrd, DP_REG_ARITHMLOGIC_SHIFTTYPE_LSB, DP_REG_ARITHMLOGIC_SHIFTTYPE_MSB);
arithmLogicData->negShiftedSrc2 = getBits(wrd, DP_REG_ARITHMLOGIC_NEGSRC2FLAG_LSB, DP_REG_ARITHMLOGIC_NEGSRC2FLAG_MSB);
switch(inst->data.DPRegisterData.DPROpType) {
case a64inst_DPR_ARITHMLOGIC:
if (arithmLogicData->type == a64inst_DPR_ARITHM && (arithmLogicData->negShiftedSrc2 || arithmLogicData->shiftType == a64inst_ROR)) {
fprintf(stderr, "Attempting to decode arithmetic DPR instruction with invalid format!\n");
}
arithmLogicData->shiftAmount = getBits(wrd, DP_REG_ARITHMLOGIC_SHIFTAMOUNT_LSB, DP_REG_ARITHMLOGIC_SHIFTAMOUNT_MSB);
break;
case a64inst_DPR_MULTIPLY:;
if (!(inst->data.DPRegisterData.processOp == DP_REG_MULTIPLY_PROCESSOP &&
arithmLogicData->type == DP_REG_MULTIPLY_ARITHMFLAG &&
arithmLogicData->shiftType == DP_REG_MULTIPLY_SHIFTTYPE &&
arithmLogicData->negShiftedSrc2 == DP_REG_MULTIPLY_NEGSRC2FLAG)) {
fprintf(stderr, "Attempting to decode multiply DPR instruction with invalid format!\n");
}
inst->data.DPRegisterData.processOpData.multiplydata.summand = getBits(wrd, DP_REG_MULTIPLY_SUMMAND_LSB, DP_REG_MULTIPLY_SUMMAND_MSB);
inst->data.DPRegisterData.processOpData.multiplydata.negProd = getBits(wrd, DP_REG_MULTIPLY_NEGPROD_LSB, DP_REG_MULTIPLY_NEGPROD_MSB);
break;
}
} else {
// Load and Store, or unknown
// Ignore unknown for now
inst->type = a64inst_SINGLETRANSFER;
inst->data.SingleTransferData.regType = getBits(wrd, SDT_REGTYPE_FLAG_LSB, SDT_REGTYPE_FLAG_MSB);
inst->data.SingleTransferData.target = getBits(wrd, SDT_TARGET_REG_LSB, SDT_TARGET_REG_MSB);
// TODO: Assert that the instruction is a Single Transfer indeed.
if(getBits(wrd, SDT_OPTYPE_FLAG_LSB, SDT_OPTYPE_FLAG_MSB) == a64inst_SINGLE_TRANSFER_SINGLE_DATA_TRANSFER) {
// Single Data Transfer
inst->data.SingleTransferData.SingleTransferOpType = a64inst_SINGLE_TRANSFER_SINGLE_DATA_TRANSFER;
inst->data.SingleTransferData.processOpData.singleDataTransferData.transferType = getBits(wrd, SDT_TRANSFER_TYPE_LSB, SDT_TRANSFER_TYPE_MSB);
inst->data.SingleTransferData.processOpData.singleDataTransferData.base = getBits(wrd, SDT_BASE_REG_LSB, SDT_BASE_REG_MSB);
if (getBits(wrd, SDT_UNSIGNED_FLAG_LSB, SDT_UNSIGNED_FLAG_MSB) == 1) {
// Unsigned offset
inst->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_UNSIGNED_OFFSET;
inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.unsignedOffset = getBits(wrd, SDT_OFFSET_LSB, SDT_OFFSET_MSB);
} else if (getBits(wrd, SDT_REGISTER_FLAG_LSB, SDT_REGISTER_FLAG_MSB) == 1) {
// Register Offset
inst->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_REGISTER_OFFSET;
inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.offsetReg = getBits(wrd, SDT_REGISTER_REG_LSB, SDT_REGISTER_REG_MSB);
} else {
// Pre-Indexed or Post-Indexed
inst->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = getBits(wrd, SDT_INDEXED_ADDRMODE_LSB, SDT_INDEXED_ADDRMODE_MSB);
inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset = getBits(wrd, SDT_INDEXED_OFFSET_LSB, SDT_INDEXED_OFFSET_MSB);
}
} else {
// Load Literal
inst->data.SingleTransferData.SingleTransferOpType = a64inst_SINGLE_TRANSFER_LOAD_LITERAL;
inst->data.SingleTransferData.processOpData.loadLiteralData.offset = getBits(wrd, SDT_LOAD_LITERAL_OFFSET_LSB, SDT_LOAD_LITERAL_OFFSET_MSB);
}
}
return inst;
}

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@ -0,0 +1,96 @@
#include "global.h"
#include "a64instruction.h"
#define HALT_WORD 0x8a000000
#define TYPE_ID_LSB 26
#define TYPE_ID_MSB 29
#define DP_IMM_ID 4
#define BRANCH_ID 5
#define DP_REG_LSB 25
#define DP_REG_MSB 26
#define DP_WIDTH_LSB 31
#define DP_WIDTH_MSB 32
#define DP_OP_LSB 29
#define DP_OP_MSB 31
#define DP_DEST_LSB 0
#define DP_DEST_MSB 5
#define DP_IMM_OPTYPE_LSB 23
#define DP_IMM_OPTYPE_MSB 26
#define DP_IMM_OPTYPE_ARITHM 2
#define DP_IMM_OPTYPE_WIDEMOV 5
#define DP_IMM_ARITHM_SHIFTFLAG_LSB 22
#define DP_IMM_ARITHM_SHIFTFLAG_MSB 23
#define DP_IMM_ARITHM_IMMVAL_LSB 10
#define DP_IMM_ARITHM_IMMVAL_MSB 22
#define DP_IMM_ARITHM_DEST_LSB 5
#define DP_IMM_ARITHM_DEST_MSB 10
#define DP_IMM_WIDEMOV_SHIFTSCALAR_LSB 21
#define DP_IMM_WIDEMOV_SHIFTSCALAR_MSB 23
#define DP_IMM_WIDEMOV_IMMVAL_LSB 5
#define DP_IMM_WIDEMOV_IMMVAL_MSB 21
#define DP_REG_SRC1_LSB 5
#define DP_REG_SRC1_MSB 10
#define DP_REG_SRC2_LSB 16
#define DP_REG_SRC2_MSB 21
#define DP_REG_OPTYPE_LSB 28
#define DP_REG_OPTYPE_MSB 29
#define DP_REG_ARITHMLOGIC_ARITHMFLAG_LSB 24
#define DP_REG_ARITHMLOGIC_ARITHMFLAG_MSB 25
#define DP_REG_ARITHMLOGIC_SHIFTTYPE_LSB 22
#define DP_REG_ARITHMLOGIC_SHIFTTYPE_MSB 24
#define DP_REG_ARITHMLOGIC_NEGSRC2FLAG_LSB 21
#define DP_REG_ARITHMLOGIC_NEGSRC2FLAG_MSB 22
#define DP_REG_ARITHMLOGIC_SHIFTAMOUNT_LSB 10
#define DP_REG_ARITHMLOGIC_SHIFTAMOUNT_MSB 16
#define DP_REG_MULTIPLY_SUMMAND_LSB 10
#define DP_REG_MULTIPLY_SUMMAND_MSB 15
#define DP_REG_MULTIPLY_NEGPROD_LSB 15
#define DP_REG_MULTIPLY_NEGPROD_MSB 16
// Defines the values for fields used for arithmetic/logic DPR instructions
// that are necessary to indicate a multiplication instruction
#define DP_REG_MULTIPLY_PROCESSOP 0
#define DP_REG_MULTIPLY_ARITHMFLAG 1
#define DP_REG_MULTIPLY_SHIFTTYPE 0
#define DP_REG_MULTIPLY_NEGSRC2FLAG 0
#define SDT_OPTYPE_FLAG_LSB 31
#define SDT_OPTYPE_FLAG_MSB 32
#define SDT_REGTYPE_FLAG_LSB 30
#define SDT_REGTYPE_FLAG_MSB 31
#define SDT_TARGET_REG_LSB 0
#define SDT_TARGET_REG_MSB 5
#define SDT_BASE_REG_LSB 5
#define SDT_BASE_REG_MSB 10
#define SDT_OFFSET_LSB 10
#define SDT_OFFSET_MSB 22
#define SDT_TRANSFER_TYPE_LSB 22
#define SDT_TRANSFER_TYPE_MSB 23
#define SDT_UNSIGNED_FLAG_LSB 24
#define SDT_UNSIGNED_FLAG_MSB 25
#define SDT_REGISTER_FLAG_LSB 21
#define SDT_REGISTER_FLAG_MSB 22
#define SDT_REGISTER_REG_LSB 16
#define SDT_REGISTER_REG_MSB 21
#define SDT_INDEXED_ADDRMODE_LSB 11
#define SDT_INDEXED_ADDRMODE_MSB 12
#define SDT_INDEXED_OFFSET_LSB 12
#define SDT_INDEXED_OFFSET_MSB 21
#define SDT_LOAD_LITERAL_OFFSET_LSB 5
#define SDT_LOAD_LITERAL_OFFSET_MSB 24
#define BRANCH_TYPE_LSB 30
#define BRANCH_TYPE_MSB 32
#define BRANCH_UNCONDITIONAL_OFFSET_LSB 0
#define BRANCH_UNCONDITIONAL_OFFSET_MSB 26
#define BRANCH_REGISTER_SRC_LSB 5
#define BRANCH_REGISTER_SRC_MSB 10
#define BRANCH_CONDITIONAL_COND_LSB 0
#define BRANCH_CONDITIONAL_COND_MSB 4
#define BRANCH_CONDITIONAL_OFFSET_LSB 5
#define BRANCH_CONDITIONAL_OFFSET_MSB 24

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@ -1,5 +1,61 @@
#include <stdlib.h> #include <stdlib.h>
#include <stdio.h>
#include "a64instruction.h"
#include "emulator.h"
#include "fileio.h"
#include "global.h"
#include "print.h"
#include "decode.h"
#include "execute.h"
extern a64inst_instruction *decode(word w);
int main(int argc, char **argv) { int main(int argc, char **argv) {
// Check the arguments
if (argc == 1) {
fprintf(stderr, "Error: An object file is required. Syntax: ./emulate <file_in> [<file_out>]");
return EXIT_FAILURE;
}
FILE *out = stdout;
if (argc > 2) {
out = fopen(argv[2], "w");
if (out == NULL) {
fprintf(stderr, "Error: Could not open file %s\n", argv[2]);
return EXIT_FAILURE;
}
}
// Initialising the machine state
Machine state = {0};
state.memory = fileio_loadBin(argv[1], MEMORY_SIZE);
state.conditionCodes = (PState){0, 1, 0, 0};
state.pc = 0x0;
// Fetch-decode-execute cycle
word wrd;
a64inst_instruction *inst;
do {
// Step 1: Fetch instruction at PC's address
wrd = readWord(state.memory, state.pc);
// Step 2: Decode instruction to internal representation
inst = decode(wrd);
// Step 3: Update processor state to reflect executing the instruction, and increment PC
execute(&state, inst);
if (inst->type != a64inst_BRANCH)
state.pc += sizeof(word);
} while (inst->type != a64inst_HALT);
state.pc -= sizeof(word);
printState(&state, out);
free(state.memory);
return EXIT_SUCCESS; return EXIT_SUCCESS;
} }

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@ -0,0 +1,32 @@
#ifndef __EMULATOR__
#define __EMULATOR__
#include "global.h"
#include <stdbool.h>
/************************************
* DEFINITIONS
************************************/
#define BYTE_BITS 8
#define WORD_BITS (BYTE_BITS * sizeof(word))
#define DWORD_BITS (BYTE_BITS * sizeof(dword))
/************************************
* STRUCTS
************************************/
typedef struct {
bool Negative;
bool Zero;
bool Carry;
bool Overflow;
} PState;
typedef struct {
dword registers[REGISTER_COUNT];
dword pc;
byte *memory;
PState conditionCodes;
} Machine;
#endif

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#include <stdlib.h>
#include <assert.h>
#include "execute.h"
#include "print.h"
// Defines the maximum value that can be held in a register
#define MAX_REG_VAL ((1 << DWORD_BITS) - 1)
// The number of bits to shift the immediate value in an arithmetic immediate data processing
// instruction if the shift flag is enabled.
#define DPI_ARITHM_SHIFT 12
// The number of bits to shift the immediate value in a wide move immediate data processing
// instruction if the shift flag is enabled.
#define DPI_WIDEMOV_SHIFT 16
// Prototypes
void execute_SDT(Machine *state, a64inst_instruction *inst);
void execute_Branch(Machine *state, a64inst_instruction *inst);
void executeMultiply(Machine *state, a64inst_instruction *inst);
// Return maximum of two dwords
static dword max(dword a, dword b) {
return a > b ? a : b;
}
// Truncate a given value to the size of a word or dword depending on the register type
static dword truncateValue(dword value, a64inst_regType regType) {
if (regType == a64inst_X) {
return value;
} else {
return (word)value;
//return value & (dword)(((dword)1 << WORD_BITS) - 1);
}
}
// Sign extend a given value to a 64-bit signed integer given the number of bits
static int64_t signExtend(dword value, unsigned int n) {
if (n == 0 || n >= 64) {
// If n_bits is 0 or greater than or equal to 64, return the value as is
return (int64_t)value;
}
uint64_t sign_bit_mask = (uint64_t)1 << (n - 1);
// Mask to isolate the n-bit value
uint64_t n_bit_mask = (sign_bit_mask << 1) - 1;
// Check if the sign bit is set
if (value & sign_bit_mask) {
// Sign bit is set, extend the sign
return (int64_t)(value | ~n_bit_mask);
} else {
// Sign bit is not set, return the value as is
return (int64_t)(value & n_bit_mask);
}
}
// Read from processor register, ensuring that a valid register specifier is given
// and accounting for the case where the zero register is accessed. Truncate
// the 32 most significant bits stored in the R register when reading W register.
static dword readRegister(Machine *state, a64inst_regSpecifier reg, a64inst_regType regType) {
assert(reg <= REGISTER_COUNT);
if (reg == ZERO_REGISTER) {
return 0;
} else {
return truncateValue(state->registers[reg], regType);
}
}
// TODO:
// Write to a processor register, ensuring that a valid register specifier is given
// and truncating the value being written when it can't fit in the specified register
static void writeRegister(Machine *state, a64inst_regSpecifier reg, a64inst_regType regType, dword value) {
assert(reg <= REGISTER_COUNT);
if (reg != ZERO_REGISTER) {
state->registers[reg] = truncateValue(value, regType);
}
}
// Returns the position of the MSB of the given register type
inline static dword getMSBPos(a64inst_regType regType) {
return (regType ? DWORD_BITS : WORD_BITS) - 1;
}
// Returns the MSB of the given value assuming it's of the size stored in the given register type
inline static uint8_t getMSB(dword value, a64inst_regType regType) {
return value >> getMSBPos(regType);
}
// Updates N and Z condition codes given the machine and a result value
static void updateCondNZ(Machine *state, dword result, a64inst_regType regType) {
state->conditionCodes.Negative = getMSB(result, regType);
state->conditionCodes.Zero = result == 0;
}
// Execute a data processing immediate instruction
static void executeDPImmediate(Machine *state, a64inst_instruction *inst) {
assert(inst->type == a64inst_DPIMMEDIATE);
a64inst_regType regType = inst->data.DPImmediateData.regType;
a64inst_regSpecifier dest = inst->data.DPImmediateData.dest;
switch(inst->data.DPImmediateData.DPIOpType) {
// Execute an arithmetic immediate data processing instruction
case a64inst_DPI_ARITHM:;
// If shift flag is enabled, logical left shift by the number of bits specified by the architecture
dword arithmImm = inst->data.DPImmediateData.processOpData.arithmData.immediate;
dword srcVal = state->registers[inst->data.DPImmediateData.processOpData.arithmData.src];
if (inst->data.DPImmediateData.processOpData.arithmData.shiftImmediate) {
arithmImm = truncateValue(arithmImm << DPI_ARITHM_SHIFT, regType);
}
switch(inst->data.DPImmediateData.processOp) {
dword result;
case(a64inst_ADDS):
result = srcVal + arithmImm;
writeRegister(state, dest, regType, result);
updateCondNZ(state, result, regType);
state->conditionCodes.Overflow = max(srcVal, arithmImm) > result;
state->conditionCodes.Carry = state->conditionCodes.Overflow;
break;
case(a64inst_ADD):
writeRegister(state, dest, regType, srcVal + arithmImm);
break;
case(a64inst_SUBS):
result = srcVal - arithmImm;
writeRegister(state, dest, regType, result);
updateCondNZ(state, result, regType);
state->conditionCodes.Overflow = srcVal < result;
state->conditionCodes.Carry = state->conditionCodes.Overflow;
break;
case(a64inst_SUB):
writeRegister(state, dest, regType, srcVal - arithmImm);
break;
// Unknown opcode detected!
default:
fprintf(stderr, "Unknown opcode detected in a DPI arithmetic instruction!\n");
break;
}
break;
// Execute a wide move immediate data processing instruction
case a64inst_DPI_WIDEMOV:;
uint8_t shiftScalar = inst->data.DPImmediateData.processOpData.wideMovData.shiftScalar;
dword wideMovImm = inst->data.DPImmediateData.processOpData.wideMovData.immediate;
// NOTE: Not checking that shiftScalar has valid value for 32bit registers. Possibly add explicit error.
//printf("%x\n", wideMovImm << (shiftScalar * DPI_WIDEMOV_SHIFT) & );
wideMovImm = truncateValue(wideMovImm << (shiftScalar * DPI_WIDEMOV_SHIFT), regType);
switch(inst->data.DPImmediateData.processOp) {
case(a64inst_MOVN):
writeRegister(state, dest, regType, ~wideMovImm);
break;
case(a64inst_MOVZ):
writeRegister(state, dest, regType, wideMovImm);
break;
case(a64inst_MOVK):;
dword result = readRegister(state, dest, regType);
result = (result & ~(((1lu << DPI_WIDEMOV_SHIFT) - 1) << shiftScalar * DPI_WIDEMOV_SHIFT)) | wideMovImm;
writeRegister(state, dest, regType, result);
break;
default:
fprintf(stderr, "Unknown opcode detected in a DPI wide move instruction!\n");
break;
}
break;
// Unknown instruction detected!
default:
fprintf(stderr, "Attempting to execute instruction with unknown DPI operand type!\n");
break;
}
}
// Execute a data processing register instruction
static void executeDPRegister(Machine *state, a64inst_instruction *inst) {
assert(inst->type == a64inst_DPREGISTER);
a64inst_regType regType = inst->data.DPRegisterData.regType;
a64inst_regSpecifier dest = inst->data.DPRegisterData.dest;
dword src1Val = readRegister(state, inst->data.DPRegisterData.src1, regType);
dword src2Val = readRegister(state, inst->data.DPRegisterData.src2, regType);
switch(inst->data.DPRegisterData.DPROpType) {
// Execute an arithmetic or logic register data processing instruction
case a64inst_DPR_ARITHMLOGIC:;
// Apply shift to value held in second register
a64inst_DPRegister_ArithmLogicData *arithmLogicData = &inst->data.DPRegisterData.processOpData.arithmLogicData;
uint8_t shiftAmount = arithmLogicData->shiftAmount;
switch(arithmLogicData->shiftType) {
case a64inst_LSL:
src2Val = truncateValue(src2Val << shiftAmount, regType);
break;
case a64inst_LSR:
src2Val = truncateValue(src2Val >> shiftAmount, regType);
break;
case a64inst_ASR:
if (regType == a64inst_X) {
src2Val = truncateValue((int64_t)src2Val >> shiftAmount, regType);
} else {
src2Val = truncateValue((int32_t)src2Val >> shiftAmount, regType);
}
break;
case a64inst_ROR:
if (arithmLogicData->type != a64inst_DPR_LOGIC) {
fprintf(stderr, "Attempting to perform ROR shift on non-logic register data processing instruction!\n");
}
src2Val = truncateValue(src2Val >> shiftAmount | src2Val << (getMSBPos(regType) - shiftAmount), regType);
break;
default:
fprintf(stderr, "Attempting to execute arithmetic/logic register data processing instruction with invalid shift type!\n");
break;
}
// Negate second operand if negShiftedSrc2 flag is enabled
if (arithmLogicData->negShiftedSrc2) {
src2Val = truncateValue(~src2Val, regType);
}
dword result;
switch(arithmLogicData->type) {
case a64inst_DPR_ARITHM:
switch(inst->data.DPRegisterData.processOp) {
case(a64inst_ADDS):
result = src1Val + src2Val;
writeRegister(state, dest, regType, result);
updateCondNZ(state, result, regType);
state->conditionCodes.Overflow = max(src1Val, src2Val) > result;
state->conditionCodes.Carry = state->conditionCodes.Overflow;
break;
case(a64inst_ADD):
writeRegister(state, dest, regType, src1Val + src2Val);
break;
case(a64inst_SUBS):
result = src1Val - src2Val;
writeRegister(state, dest, regType, result);
updateCondNZ(state, result, regType);
state->conditionCodes.Overflow = getMSB(src1Val, regType) != getMSB(src2Val, regType) && getMSB(src1Val, regType) != getMSB(result, regType);
state->conditionCodes.Carry = src1Val >= src2Val;
break;
case(a64inst_SUB):
writeRegister(state, dest, regType, src1Val - src2Val);
break;
// Unknown opcode detected!
default:
fprintf(stderr, "Unknown opcode detected in a DPI arithmetic instruction!\n");
break;
}
break;
case a64inst_DPR_LOGIC:
switch(inst->data.DPRegisterData.processOp) {
case a64inst_AND:
writeRegister(state, dest, regType, src1Val & src2Val);
break;
case a64inst_OR:
writeRegister(state, dest, regType, src1Val | src2Val);
break;
case a64inst_XOR:
writeRegister(state, dest, regType, src1Val ^ src2Val);
break;
case a64inst_AND_FLAGGED:;
result = src1Val & src2Val;
writeRegister(state, dest, regType, result);
state->conditionCodes.Overflow = 0;
state->conditionCodes.Carry = 0;
updateCondNZ(state, result, regType);
break;
}
break;
default:
fprintf(stderr, "Attempting to execute an instruction with an unknown DPR arithmetic or logic subtype!\n");
break;
}
break;
// Execute a multiply register data processing instruction
case a64inst_DPR_MULTIPLY:
break;
// Unknown instruction detected!
default:
fprintf(stderr, "Attempting to execute instruction with unknown DPR operand type!\n");
break;
}
}
void execute(Machine *state, a64inst_instruction *inst) {
switch (inst->type) {
// Halt the program
case a64inst_HALT:
break;
// Execute a data processing immediate instruction
case a64inst_DPIMMEDIATE:
executeDPImmediate(state, inst);
break;
// Execute a branch instruction
case a64inst_BRANCH:
execute_Branch(state, inst);
break;
// Execute a data processing register instruction
case a64inst_DPREGISTER:
if (inst->data.DPRegisterData.DPROpType == a64inst_DPR_MULTIPLY)
executeMultiply(state, inst);
else
executeDPRegister(state, inst);
break;
case a64inst_SINGLETRANSFER:
execute_SDT(state, inst);
break;
// Unknown instruction
default:
break;
}
}
void execute_SDT(Machine *state, a64inst_instruction *inst) {
word address;
bool isLoad;
if (inst->data.SingleTransferData.SingleTransferOpType == a64inst_SINGLE_TRANSFER_LOAD_LITERAL) {
// Load Literal
isLoad = true;
address = state->pc + inst->data.SingleTransferData.processOpData.loadLiteralData.offset * 4;
} else {
address = state->registers[inst->data.SingleTransferData.processOpData.singleDataTransferData.base];
isLoad = inst->data.SingleTransferData.processOpData.singleDataTransferData.transferType == a64inst_LOAD;
switch (inst->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode) {
case a64inst_UNSIGNED_OFFSET:
address += inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.unsignedOffset * (inst->data.SingleTransferData.regType == a64inst_W ? 4 : 8);
break;
case a64inst_REGISTER_OFFSET:
address += state->registers[inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.offsetReg];
break;
case a64inst_PRE_INDEXED:
address += inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset;
state->registers[inst->data.SingleTransferData.processOpData.singleDataTransferData.base] = address;
break;
case a64inst_POST_INDEXED:
state->registers[inst->data.SingleTransferData.processOpData.singleDataTransferData.base] = address + inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset;
break;
}
}
if (isLoad) {
if (inst->data.SingleTransferData.regType == a64inst_W) {
// 32 bit access
state->registers[inst->data.SingleTransferData.target] = readWord(state->memory, address);
} else {
state->registers[inst->data.SingleTransferData.target] = readDoubleWord(state->memory, address);
}
} else {
*(word *)(state->memory + address) = state->registers[inst->data.SingleTransferData.target];
// Update base register if post indexed
if (inst->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode == a64inst_POST_INDEXED) {
writeRegister(state, inst->data.SingleTransferData.processOpData.singleDataTransferData.base, inst->data.SingleTransferData.regType == a64inst_W, address + inst->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset);
}
}
}
static bool isConditionMet(Machine* state, a64inst_ConditionType cond) {
switch(cond) {
case EQ:
return state->conditionCodes.Zero;
case NE:
return !state->conditionCodes.Zero;
case GE:
return state->conditionCodes.Negative == state->conditionCodes.Overflow;
case LT:
return state->conditionCodes.Negative != state->conditionCodes.Overflow;
case GT:
return !state->conditionCodes.Zero && (state->conditionCodes.Negative == state->conditionCodes.Overflow);
case LE:
return state->conditionCodes.Zero || (state->conditionCodes.Negative != state->conditionCodes.Overflow);
case AL:
return true;
default:
fprintf(stderr, "Unknown condition specified!\n");
exit(1);
}
}
void execute_Branch(Machine *state, a64inst_instruction *inst) {
switch (inst->data.BranchData.BranchType) {
case a64inst_UNCONDITIONAL:
state->pc += signExtend(inst->data.BranchData.processOpData.unconditionalData.unconditionalOffset * 4, 26);
break;
case a64inst_REGISTER:
state->pc = state->registers[inst->data.BranchData.processOpData.registerData.src];
break;
case a64inst_CONDITIONAL:
if (isConditionMet(state, inst->data.BranchData.processOpData.conditionalData.cond)) {
state->pc += signExtend(inst->data.BranchData.processOpData.conditionalData.offset * 4, 19);
}
break;
}
}
void executeMultiply(Machine *state, a64inst_instruction *inst) {
dword product = state->registers[inst->data.DPRegisterData.src1] * state->registers[inst->data.DPRegisterData.src2];
dword sum = readRegister(state, inst->data.DPRegisterData.processOpData.multiplydata.summand, inst->data.DPRegisterData.regType) + (inst->data.DPRegisterData.processOpData.multiplydata.negProd ? -product : product);
writeRegister(state, inst->data.DPRegisterData.dest, inst->data.DPRegisterData.regType, sum);
}

7
src/execute.h Normal file
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@ -0,0 +1,7 @@
#ifndef __EXECUTE__
#define __EXECUTE__
#include "a64instruction.h"
#include "emulator.h"
void execute(Machine *state, a64inst_instruction *inst);
#endif

View File

@ -1,62 +1,48 @@
#include <assert.h>
#include <stdio.h> #include <stdio.h>
#include <string.h> #include <string.h>
#include "fileio.h"
#include "global.h"
//validates inputted charlist as valid filename against expected extension /* Loads a binary file located at filePath to memory, taking up a block of exactly memorySize bytes,
int isValidFileFormat(char filename[], char expectedExtension[]){ and returns the starting address of the data. If memorySize is insufficient to store the entire file,
int *pointLoc = strrchr(filename, '.'); an appropriate error is reported. Excess memory is set to 0 bit values. */
if(pointLoc != NULL){ byte *fileio_loadBin(const char *filePath, size_t memorySize) {
if(strcmp(pointLoc, expectedExtension)==0){ FILE *file = fopen(filePath, "rb");
return(1); if (file == NULL) {
fprintf(stderr, "Couldn't open %s!\n", filePath);
exit(EXIT_FAILURE);
}
byte *fileData = malloc(memorySize);
if (fileData == NULL) {
fprintf(stderr, "Ran out of memory attempting to load %s!\n", filePath);
exit(EXIT_FAILURE);
}
// Loop while reading from the file yields data. Only terminates if EOF is reached or ERROR occurs.
// Explicitly deal with attempting to write too much data to memory block, rather than allow segfault.
const size_t byteCount = memorySize/sizeof(byte);
int i = 0;
while (fread(fileData + i, sizeof(byte), 1, file)) {
if (i >= byteCount) {
fprintf(stderr, "Attempting to load binary %s to memory of smaller size %zu!\n", filePath, memorySize);
exit(EXIT_FAILURE);
} }
i++;
} }
return(0);
if (ferror(file)) {
fprintf(stderr, "Encountered error attempting to read %s!\n", filePath);
exit(EXIT_FAILURE);
}
assert(fclose(file) != EOF);
// If part of memory block was left uninitialized, initialize it to zero.
if (i < byteCount) {
memset(fileData + i, 0, (byteCount - i) * sizeof(byte));
}
return fileData;
} }
//writes a list of words (list of binary instructions) to a named output file
int writeBinaryFile(word instrs[], char outputFile[]){
if (!isValidFileFormat(filename, "bin")){
exit(EXIT_FAILURE);
}
FILE *fp;
fp = fopen(outputFile, "wb");
if(fp == NULL){
exit(EXIT_FAILURE);
}
fwrite(instrs, sizeof(word), sizeof(instrs), fp);
fclose(fp);
exit(EXIT_SUCCESS);
}
//reads assembly file of "inputFile" name, and passes
//each line into a parser
//TODO: allocate whole file in memory, line-by-line
int readAssemblyFile(char inputFile[]) {
if (!isValidFileFormat(filename, "s")){
exit(EXIT_FAILURE);
}
FILE *fp;
char savedLine[sizeof(a64inst_instruction)];
fp = fopen(inputFile, "r");
if(fp == NULL){
exit(EXIT_FAILURE);
}
while (fgets(savedLine, MAX_ASM_LINE_LENGTH-1, fp) != NULL) {
// removes newline char before saving them
savedLine[strcspn(savedLine, "\n")] = 0;
}
exit(EXIT_SUCCESS);
}

9
src/fileio.h Normal file
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@ -0,0 +1,9 @@
#ifndef __FILEIO__
#define __FILEIO__
#include <stdlib.h>
#include "global.h"
#define EXIT_FAILURE 1
extern byte *fileio_loadBin(const char *filePath, size_t memorySize);
#endif

View File

@ -11,6 +11,8 @@
// Number of General Purpose Registers. // Number of General Purpose Registers.
#define REGISTER_COUNT 31 #define REGISTER_COUNT 31
// Register identifier interpreted as the 'zero register'
#define ZERO_REGISTER 31
// Size of the memory in bytes. // Size of the memory in bytes.
#define MEMORY_SIZE 2097152 #define MEMORY_SIZE 2097152
// Length of the memory address in bits. // Length of the memory address in bits.
@ -25,4 +27,4 @@ typedef uint32_t word;
// Double word is a 64-bit unsigned integer. // Double word is a 64-bit unsigned integer.
typedef uint64_t dword; typedef uint64_t dword;
#endif #endif

58
src/print.c Normal file
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@ -0,0 +1,58 @@
#include <stdbool.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>
#include "print.h"
#include "emulator.h"
#define UNSET_CONDITION_CODE_CHAR '-'
// Prints the current machine state into the provided stream
void printState(Machine *state, FILE *stream) {
printRegisters(state, stream);
printMemory(state, stream);
}
// Prints the current machine registers into the provided stream
void printRegisters(Machine *state, FILE *stream) {
fprintf(stream, "Registers:\n");
for (int i = 0; i < REGISTER_COUNT; i++) {
fprintf(stream, "X%02d\t= %016" PRIx64 "\n", i, state->registers[i]);
}
fprintf(stream, "PC\t= %016" PRIx64 "\n", state->pc);
fprintf(stream, "PSTATE\t: %c%c%c%c", state->conditionCodes.Negative ? 'N' : UNSET_CONDITION_CODE_CHAR,
state->conditionCodes.Zero ? 'Z' : UNSET_CONDITION_CODE_CHAR,
state->conditionCodes.Carry ? 'C' : UNSET_CONDITION_CODE_CHAR,
state->conditionCodes.Overflow ? 'V' : UNSET_CONDITION_CODE_CHAR);
}
// Returns the word starting at the provided address
word readWord(byte *memory, uint32_t address) {
word result = 0;
int bytesPerWord = WORD_BITS / BYTE_BITS - 1;
for (int i = 0; i <= bytesPerWord; i++)
result |= (word) memory[address + i] << (BYTE_BITS * i);
return result;
}
// Returns the double word starting at the provided address
dword readDoubleWord(byte *memory, uint32_t address) {
dword result = 0;
int bytesPerDword = DWORD_BITS / BYTE_BITS - 1;
for (int i = 0; i <= bytesPerDword; i++)
result |= (dword) memory[address + i] << (BYTE_BITS * i);
return result;
}
// Prints all non-zero memory locations into the provided stream
void printMemory(Machine *state, FILE *stream) {
fprintf(stream, "\nNon-zero memory:\n");
// print memory 4 byte aligned
for (int addr = 0; addr < MEMORY_SIZE; addr+= 4) {
word data = readWord(state->memory, addr);
if (data != 0) {
fprintf(stream, "0x%08x: %08x\n", addr, data);
}
}
}

12
src/print.h Normal file
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@ -0,0 +1,12 @@
#ifndef __PRINT__
#define __PRINT__
#include <stdio.h>
#include "emulator.h"
word readWord(byte *memory, uint32_t address);
dword readDoubleWord(byte *memory, uint32_t address);
void printState(Machine *state, FILE *stream);
void printRegisters(Machine *state, FILE *stream);
void printMemory(Machine *state, FILE *stream);
#endif

24
test.sh Normal file
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@ -0,0 +1,24 @@
echo "Trying to compile the program..."
make -C src
echo "Fetching the test suite..."
git clone https://gitlab.doc.ic.ac.uk/teaching-fellows/armv8_testsuite.git
mkdir armv8_testsuite/solution
cp -R src/. ./armv8_testsuite/solution
cd armv8_testsuite
python3 -m pip install -r requirements.txt
./install
echo "Running the test suite..."
./run -s
echo "Test Suite Completed"
cd ..
# printf "%s " "Press enter to continue"
# read ans
echo "Cleaning Up..."
make -C src clean
rm -rf armv8_testsuite
echo "Done"