summaryrefslogtreecommitdiff
path: root/mips.c
diff options
context:
space:
mode:
Diffstat (limited to 'mips.c')
-rw-r--r--mips.c315
1 files changed, 0 insertions, 315 deletions
diff --git a/mips.c b/mips.c
deleted file mode 100644
index dcda5f7..0000000
--- a/mips.c
+++ /dev/null
@@ -1,315 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <string.h>
-#include <arpa/inet.h>
-
-#define MEM_SIZE 36
-#define RA 31
-#define V0 2
-#define V1 3
-#define A0 4
-#define A1 5
-#define A2 6
-#define A3 7
-#define WORD_SIZE 4
-
-typedef struct {
- unsigned int op: 6;
- unsigned int rs: 5;
- unsigned int rt: 5;
- unsigned int rd: 5;
- unsigned int shamt: 5;
- unsigned int func: 6;
-} rtype_t;
-
-typedef struct {
- unsigned int op: 6;
- unsigned int rs: 5;
- unsigned int rt: 5;
- unsigned int imm: 16;
-} itype_t;
-
-typedef struct {
- unsigned int op: 6;
- unsigned int addr: 26;
-} jtype_t;
-
-typedef enum { NOP, RTYPE, ITYPE, JTYPE } type_t;
-
-typedef struct {
- type_t type;
- union {
- uint32_t value;
- rtype_t r;
- jtype_t j;
- itype_t i;
- };
-} inst_t;
-
-uint8_t memory[MEM_SIZE] = {0};
-uint32_t pc = 0, hi = 0, lo = 0;
-uint32_t regFile[32] = {0};
-
-/* InstFetch: Fetch the next instruction from memory into the given
- * instruction */
-void InstFetch(inst_t *inst) {
- uint32_t value = 0;
- memcpy(&value, memory + pc, WORD_SIZE);
- switch ((value & 0xFC000000) >> 24) {
- case 0:
- inst->type = RTYPE;
- inst->r.op = (value & 0xFC000000) >> 26;
- inst->r.rs = (value & 0x03E00000) >> 21;
- inst->r.rt = (value & 0x001F0000) >> 16;
- inst->r.rd = (value & 0x0000F800) >> 11;
- inst->r.shamt = (value & 0x000007C0) >> 6;
- inst->r.func = value & 0x0000002F;
- break;
- case 2:
- case 3:
- inst->type = JTYPE;
- inst->j.op = (value & 0xFC000000) >> 26;
- inst->j.addr = value & 0X03FFFFFF;
- break;
- default:
- inst->type = ITYPE;
- inst->i.op = (value & 0xFC000000) >> 26;
- inst->i.rs = (value & 0x03E00000) >> 21;
- inst->i.rt = (value & 0x001F0000) >> 16;
- inst->i.imm = value & 0x0000FFFF;
- break;
- }
- if (inst->value == 0) {
- inst->type = NOP;
- }
- pc += WORD_SIZE;
-}
-
-void Syscall(void) {
- char c, *s;
- switch (regFile[V0]) {
- case 1: // print integer
- printf("%d", regFile[A0]);
- break;
- case 2: // print float
- break;
- case 3: // print double
- break;
- case 4: // print string
- printf("%s", memory + regFile[A0]);
- break;
- case 5: // read integer
- scanf("%d", (int *)regFile + V0);
- break;
- case 6: // read float
- break;
- case 7: // read double
- break;
- case 8: // read string
- s = (char *)calloc(regFile[A0], sizeof(char));
- fgets(s, regFile[A0], stdin);
- memcpy(memory + regFile[A1], s, regFile[A0]);
- free(s);
- break;
- case 9: // sbrk
- break;
- case 10: //exit
- exit(0);
- case 11: // print char
- printf("%c", regFile[A0]);
- break;
- case 12: // read char
- c = 0;
- scanf("%c", &c);
- regFile[V0] = c;
- break;
- case 13: // open file
- break;
- case 14: // read from file
- break;
- case 15: // write to file
- break;
- case 16: // close file
- break;
- case 17: // exit2
- exit(regFile[A0]);
- }
-}
-
-/* ExecRtype: Execute a given R-Type instruction */
-void ExecRtype(const inst_t inst) {
- rtype_t r = inst.r;
- uint32_t a = regFile[r.rs], b = regFile[r.rt];
- uint64_t mult = 0;
- switch (r.func) {
- case 32: // add
- regFile[r.rd] = (signed)a + (signed)b;
- break;
- case 33: // addu
- regFile[r.rd] = a + b;
- break;
- case 36: // and
- regFile[r.rd] = a & b;
- break;
- case 37: // or
- regFile[r.rd] = a | b;
- break;
- case 42: // slt
- regFile[r.rd] = (signed)a < (signed)b;
- break;
- case 43: // sltu
- regFile[r.rd] = a < b;
- break;
- case 34: // sub
- regFile[r.rd] = (signed)a - (signed)b;
- break;
- case 35: // subu
- regFile[r.rd] = a - b;
- break;
- case 38: // xor
- regFile[r.rd] = a ^ b;
- break;
- case 0: // sll
- regFile[r.rd] = b << r.shamt;
- break;
- case 3: // sra
- regFile[r.rd] = (signed)b >> r.shamt;
- break;
- case 2: // srl
- regFile[r.rd] = b >> r.shamt;
- break;
- case 26: // div
- hi = (signed)a % (signed)b;
- lo = (signed)a / (signed)b;
- break;
- case 27: // divu
- hi = a % b;
- lo = a / b;
- break;
- case 24: // mult
- mult = (signed)a * (signed)b;
- hi = (0xFFFFFFFF00000000 & mult) >> 32;
- lo = 0x00000000FFFFFFFF & mult;
- break;
- case 25: // multu
- mult = a * b;
- hi = (0xFFFFFFFF00000000 & mult) >> 32;
- lo = 0x00000000FFFFFFFF & mult;
- break;
- case 16: // MFHI
- regFile[r.rd] = hi;
- break;
- case 18: // MFLO
- regFile[r.rd] = lo;
- break;
- case 17: // MTHI
- hi = regFile[r.rs];
- break;
- case 19: // MTLO
- lo = regFile[r.rs];
- break;
- case 8: // jr
- pc = a;
- break;
- case 9: // jalr
- regFile[r.rd] = pc + 4;
- pc = a;
- break;
- case 12: // syscall
- Syscall();
- break;
- }
-}
-
-/* InstExec: Execute a given instruction */
-void InstExec(const inst_t inst) {
- if (inst.type == NOP) {
- return;
- }
- switch (inst.j.op) {
- case 0: // R-type instruction
- ExecRtype(inst);
- break;
- case 3: // jal
- regFile[RA] = pc + 4;
- /* intentional fall through */
- case 2: // j
- pc = (0xF0000000 & pc ) | inst.j.addr;
- break;
- case 4: // beq
- pc = (regFile[inst.i.rs] == regFile[inst.i.rt]) ? pc + 4 +
- inst.i.imm : pc;
- break;
- case 5: // bne
- pc = (regFile[inst.i.rs] != regFile[inst.i.rt]) ? pc + 4 +
- inst.i.imm : pc;
- break;
- case 8: // addi
- regFile[inst.i.rt] = (signed)inst.i.rs + (signed)inst.i.imm;
- break;
- case 9: // addiu
- regFile[inst.i.rt] = inst.i.rs + inst.i.imm;
- break;
- case 12: // andi
- regFile[inst.i.rt] = inst.i.rs & inst.i.imm;
- break;
- case 13: // ori
- regFile[inst.i.rt] = inst.i.rs | inst.i.imm;
- break;
- case 14: // xori
- regFile[inst.i.rt] = inst.i.rs ^ inst.i.imm;
- break;
- case 10: // slti
- regFile[inst.i.rt] = (signed)inst.i.rs < (signed)inst.i.imm;
- break;
- case 11: // sltiu
- regFile[inst.i.rt] = inst.i.rs < inst.i.imm;
- break;
- case 15: // lui
- regFile[inst.i.rt] = inst.i.imm << 16;
- break;
- case 35: // lw
- memcpy(regFile + inst.i.rs, memory + inst.i.rt + inst.i.imm,
- WORD_SIZE);
- break;
- case 43: // sw
- memcpy(memory + inst.i.rt + inst.i.imm, regFile + inst.i.rs,
- WORD_SIZE);
- break;
- }
-}
-
-void CycleCpu(void) {
- inst_t instFetch, instExec;
- memset(&instFetch, 0, sizeof(inst_t));
- memset(&instExec, 0, sizeof(inst_t));
- while (pc < MEM_SIZE) {
- InstFetch(&instFetch);
- InstExec(instExec);
- instExec = instFetch;
- }
-}
-
-int LoadBinary(const char * const path) {
- FILE *fp = fopen(path, "r");
- if (fp == NULL) {
- perror("LoadBinary");
- return -1;
- }
- int8_t byte = 0;
- size_t i = 0;
- while ((byte = fgetc(fp)) != EOF && i < MEM_SIZE) {
- memory[i++] = byte;
- }
- fclose(fp);
- return 0;
-}
-
-int main(int argc, char *argv[]) {
- if (LoadBinary(*++argv) == -1) {
- return -1;
- }
- CycleCpu();
-}
-
generated by cgit v1.2.3 (git 2.46.0) at 2026-05-16 08:06:25 +0000