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This commit is contained in:
Bruno Rybársky
2025-02-05 14:08:20 +01:00
parent de77a0a9f5
commit 2daec68484
4 changed files with 91 additions and 63 deletions
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123
cpu/core.c
View File

@@ -47,55 +47,64 @@ void step(CPU *cpu) {
case INC_RN: case INC_RN:
//Increment register //Increment register
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
temp = read_reg(cpu, reg1);
write_reg(cpu, reg1, temp + 1);
cpu->regs[reg1]++; cpu->regs[reg1]++;
case INC_ADDR: case INC_ADDR:
//Increment address //Increment address
addrTemp = read_addr(cpu); addrTemp = read_address(cpu);
write_mem(cpu, read_addr(cpu), read_mem(cpu, addrTemp) + 1); temp = read_mem(cpu, addrTemp);
write_mem(cpu, addrTemp, temp + 1);
case DEC_RN: case DEC_RN:
//Decrement register //Decrement register
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
cpu->regs[reg1]--; temp = read_reg(cpu, reg1);
write_reg(cpu, reg1, temp - 1);
cpu->regs[reg1]++;
case DEC_ADDR: case DEC_ADDR:
//Decrement address //Decrement address
addrTemp = read_addr(cpu); addrTemp = read_address(cpu);
write_mem(cpu, addrTemp, read_mem(cpu, addrTemp) - 1); temp = read_mem(cpu, addrTemp);
write_mem(cpu, addrTemp, temp - 1);
case MOV_RN_IMM: case MOV_RN_IMM:
//Load from immediate to register //Load from immediate to register
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] = imm; cpu->regs[reg1] = imm;
break; break;
case MOV_RN_RM: case MOV_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
cpu->regs[reg1] = cpu->regs[reg2]; temp = read_reg(cpu, reg1);
write_reg(cpu, reg2, temp);
break; break;
case MOV_RN_ADDR: case MOV_RN_ADDR:
// Load from memory into register. // Store register to memory
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); addrTemp = read_address(cpu);
cpu->regs[reg1] = read_mem(cpu, imm); temp = read_reg(cpu, reg1);
write_mem(cpu, addrTemp, temp);
break; break;
case MOV_ADDR_RN: case MOV_ADDR_RN:
// Store from register into memory. // Load memory to register
imm = read_mem(cpu, cpu->pc++); addrTemp = read_address(cpu);
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
write_mem(cpu, imm, cpu->regs[reg1]); temp = read
write_mem(cpu, addrTemp, cpu->regs[reg1]);
break; break;
case SWAP: { case SWAP: {
// Swap contents of two registers. // Swap contents of two registers.
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
temp = cpu->regs[reg1]; temp = cpu->regs[reg1];
cpu->regs[reg1] = cpu->regs[reg2]; cpu->regs[reg1] = cpu->regs[reg2];
cpu->regs[reg2] = temp; cpu->regs[reg2] = temp;
@@ -104,57 +113,57 @@ void step(CPU *cpu) {
case SWAPN: { case SWAPN: {
// Swap the nibbles of a register. // Swap the nibbles of a register.
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
uint8_t val = (uint8_t) cpu->regs[reg1]; uint8_t val = (uint8_t) cpu->regs[reg1];
cpu->regs[reg1] = ((val & 0x0F) << 4) | ((val & 0xF0) >> 4); cpu->regs[reg1] = ((val & 0x0F) << 4) | ((val & 0xF0) >> 4);
break; break;
} }
case ADD_RN_RM: case ADD_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
cpu->regs[reg1] += cpu->regs[reg2]; cpu->regs[reg1] += cpu->regs[reg2];
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case ADD_RN_IMM: case ADD_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] += imm; cpu->regs[reg1] += imm;
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case SUB_RN_RM: case SUB_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
cpu->regs[reg1] -= cpu->regs[reg2]; cpu->regs[reg1] -= cpu->regs[reg2];
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case SUB_RN_IMM: case SUB_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] -= imm; cpu->regs[reg1] -= imm;
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case MUL_RN_RM: case MUL_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
cpu->regs[reg1] *= cpu->regs[reg2]; cpu->regs[reg1] *= cpu->regs[reg2];
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case MUL_RN_IMM: case MUL_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] *= imm; cpu->regs[reg1] *= imm;
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case DIV_RN_RM: case DIV_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
if (cpu->regs[reg2] == 0) { if (cpu->regs[reg2] == 0) {
printf("Error: Division by zero!\n"); printf("Error: Division by zero!\n");
cpu->mode = Error; cpu->mode = Error;
@@ -165,7 +174,7 @@ void step(CPU *cpu) {
break; break;
case DIV_RN_IMM: case DIV_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
if (imm == 0) { if (imm == 0) {
printf("Error: Division by zero!\n"); printf("Error: Division by zero!\n");
@@ -177,8 +186,8 @@ void step(CPU *cpu) {
break; break;
case MOD_RN_RM: case MOD_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
if (cpu->regs[reg2] == 0) { if (cpu->regs[reg2] == 0) {
printf("Error: Modulo by zero!\n"); printf("Error: Modulo by zero!\n");
cpu->mode = Error; cpu->mode = Error;
@@ -189,7 +198,7 @@ void step(CPU *cpu) {
break; break;
case MOD_RN_IMM: case MOD_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
if (imm == 0) { if (imm == 0) {
printf("Error: Modulo by zero!\n"); printf("Error: Modulo by zero!\n");
@@ -201,75 +210,75 @@ void step(CPU *cpu) {
break; break;
case NEG_RN: case NEG_RN:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
cpu->regs[reg1] = -((int32_t) cpu->regs[reg1]); cpu->regs[reg1] = -((int32_t) cpu->regs[reg1]);
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case AND_RN_RM: case AND_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
cpu->regs[reg1] &= cpu->regs[reg2]; cpu->regs[reg1] &= cpu->regs[reg2];
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case AND_RN_IMM: case AND_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] &= imm; cpu->regs[reg1] &= imm;
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case OR_RN_RM: case OR_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
cpu->regs[reg1] |= cpu->regs[reg2]; cpu->regs[reg1] |= cpu->regs[reg2];
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case OR_RN_IMM: case OR_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] |= imm; cpu->regs[reg1] |= imm;
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case XOR_RN_RM: case XOR_RN_RM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
cpu->regs[reg1] ^= cpu->regs[reg2]; cpu->regs[reg1] ^= cpu->regs[reg2];
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case XOR_RN_IMM: case XOR_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] ^= imm; cpu->regs[reg1] ^= imm;
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case NOT_RN: case NOT_RN:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
cpu->regs[reg1] = ~cpu->regs[reg1]; cpu->regs[reg1] = ~cpu->regs[reg1];
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case SHL_RN_IMM: case SHL_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] <<= imm; cpu->regs[reg1] <<= imm;
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case SHR_RN_IMM: case SHR_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
cpu->regs[reg1] >>= imm; // Logical right shift (assuming unsigned value) cpu->regs[reg1] >>= imm; // Logical right shift (assuming unsigned value)
set_flags(cpu, cpu->regs[reg1]); set_flags(cpu, cpu->regs[reg1]);
break; break;
case SAR_RN_IMM: case SAR_RN_IMM:
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
imm = read_mem(cpu, cpu->pc++); imm = read_mem(cpu, cpu->pc++);
// Arithmetic right shift; cast to signed before shifting. // Arithmetic right shift; cast to signed before shifting.
cpu->regs[reg1] = ((int32_t) cpu->regs[reg1]) >> imm; cpu->regs[reg1] = ((int32_t) cpu->regs[reg1]) >> imm;
@@ -289,8 +298,8 @@ void step(CPU *cpu) {
case CMP: { case CMP: {
// Compare two registers: set flags (Zero, Negative) // Compare two registers: set flags (Zero, Negative)
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
reg2 = read_reg(cpu); reg2 = read_reg_number(cpu);
cmpResult = (int32_t) cpu->regs[reg1] - (int32_t) cpu->regs[reg2]; cmpResult = (int32_t) cpu->regs[reg1] - (int32_t) cpu->regs[reg2];
set_flags(cpu, cmpResult); set_flags(cpu, cmpResult);
break; break;
@@ -298,7 +307,7 @@ void step(CPU *cpu) {
case JE_BIT_RN: { case JE_BIT_RN: {
// Jump if bit in register set // Jump if bit in register set
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
if (reg1 >= REG_COUNT) { if (reg1 >= REG_COUNT) {
reg1 = REG_COUNT - 1; reg1 = REG_COUNT - 1;
} }
@@ -342,7 +351,7 @@ void step(CPU *cpu) {
case JNE_BIT_RN: { case JNE_BIT_RN: {
// Jump if bit in register set // Jump if bit in register set
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
if (reg1 >= REG_COUNT) { if (reg1 >= REG_COUNT) {
reg1 = REG_COUNT - 1; reg1 = REG_COUNT - 1;
} }
@@ -437,14 +446,14 @@ void step(CPU *cpu) {
case PUSH: { case PUSH: {
// Push register value onto the stack. // Push register value onto the stack.
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
write_mem(cpu, cpu->sp--, (uint8_t) cpu->regs[reg1]); write_mem(cpu, cpu->sp--, (uint8_t) cpu->regs[reg1]);
break; break;
} }
case POP: { case POP: {
// Pop a value from the stack into a register. // Pop a value from the stack into a register.
reg1 = read_reg(cpu); reg1 = read_reg_number(cpu);
cpu->regs[reg1] = read_mem(cpu, ++cpu->sp); cpu->regs[reg1] = read_mem(cpu, ++cpu->sp);
break; break;
} }

2
cpu/core.h
View File

@@ -17,7 +17,7 @@ enum Mode {
MaxSpeed MaxSpeed
}; };
#define MEM_SIZE 8192 #define MEM_SIZE 65535
// Register count (register names R0 to R7) // Register count (register names R0 to R7)
#define REG_COUNT 32 #define REG_COUNT 32

21
cpu/memory.c
View File

@@ -37,7 +37,7 @@ uint32_t read_mem32(CPU *cpu, uint32_t addr) {
return read_mem16(cpu, addr) | (read_mem16(cpu, addr + 2) << 16); return read_mem16(cpu, addr) | (read_mem16(cpu, addr + 2) << 16);
} }
uint32_t read_addr(CPU *cpu) { uint32_t read_address(CPU *cpu) {
uint32_t out = read_mem16(cpu, cpu->pc) | (read_mem16(cpu, cpu->pc + 2) << 16); uint32_t out = read_mem16(cpu, cpu->pc) | (read_mem16(cpu, cpu->pc + 2) << 16);
cpu->pc += 4; cpu->pc += 4;
if (out >= MEM_SIZE) { if (out >= MEM_SIZE) {
@@ -46,14 +46,29 @@ uint32_t read_addr(CPU *cpu) {
return out; return out;
} }
uint8_t read_reg(CPU *cpu) { uint8_t read_reg_number(CPU *cpu) {
uint8_t out = read_mem(cpu, cpu->pc++); uint8_t out = read_mem(cpu, cpu->pc++);
if (out >= REG_COUNT) { if (out >= REG_COUNT) {
out = REG_COUNT - 1; return 0;
} }
return out; return out;
} }
uint8_t read_reg(CPU *cpu, uint8_t number) {
if (number >= REG_COUNT) {
return 0;
}
return cpu->regs[number];
}
uint8_t write_reg(CPU *cpu, uint8_t number, uint8_t value) {
if (number >= REG_COUNT) {
return 1;
}
cpu->regs[number] = value;
return 0;
}
uint8_t write_mem16(CPU *cpu, uint32_t addr, uint16_t value) { uint8_t write_mem16(CPU *cpu, uint32_t addr, uint16_t value) {
uint8_t status = write_mem(cpu, addr, value & 0xFF); uint8_t status = write_mem(cpu, addr, value & 0xFF);
if (status) { if (status) {

8
cpu/memory.h
View File

@@ -14,9 +14,13 @@ uint8_t write_mem16(CPU *cpu, uint32_t addr, uint16_t value);
uint32_t read_mem32(CPU *cpu, uint32_t addr); uint32_t read_mem32(CPU *cpu, uint32_t addr);
uint32_t read_addr(CPU *cpu); uint32_t read_address(CPU *cpu);
uint8_t read_reg(CPU *cpu); uint8_t read_reg_number(CPU *cpu);
uint8_t read_reg(CPU *cpu, uint8_t number);
uint8_t write_reg(CPU *cpu, uint8_t number, uint8_t value);
uint16_t read_mem16(CPU *cpu, uint32_t addr); uint16_t read_mem16(CPU *cpu, uint32_t addr);