rvemu

commit ed69a16140d8f2310eb22e84cd4856afc674e51e
parent 58dc93d516ee655d43250e283d455b3e59e7f12b
Author: Michail Konstantinos Dimopoulos <mk@mcdim.xyz>
Date:   Fri, 24 Jul 2026 00:42:32 +0300

Crude debugger interface

Diffstat:
M
main.c
 | 
81
++++++++++++++++++++++++++++++++++++++++++-------------------------------------

1 file changed, 43 insertions(+), 38 deletions(-)
diff --git a/main.c b/main.c
@@ -2,6 +2,7 @@
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #define MEMSIZE 2052
 
@@ -454,7 +455,8 @@ void exec_btype(cpu_state_t *cpu, uint32_t inst, uint8_t *mem) {
 	/**/uint32_t raw_imm = (imm_12   << 12) | (imm_11   << 11) | (imm_10_5 << 5)  | (imm_4_1  << 1);
 	/**/if (raw_imm & (1U << 12))
         /**/ 	raw_imm |= 0xffffe000U;
-	b.imm = (int32_t)(0 | (imm_4_1 << 1) | (imm_10_5 << 5) | (imm_11 << 11) | (imm_12 << 12));
+	//b.imm = (int32_t)(0 | (imm_4_1 << 1) | (imm_10_5 << 5) | (imm_11 << 11) | (imm_12 << 12));
+	b.imm = (int32_t)raw_imm;
 
 	b.funct3 = (inst >> 12) & 7;
 	b.rs1 = (inst >> 15) & 31;
@@ -480,8 +482,6 @@ void exec_btype(cpu_state_t *cpu, uint32_t inst, uint8_t *mem) {
 	printf("\n");
 	/*********/
 
-	//printf("PC:%d\n", cpu->pc);
-	/**/printf("PC before: %" PRIu32 "\n", cpu->pc);
 	switch (b.funct3) {
 	case 0x0:
 		if (cpu->x[b.rs1] == cpu->x[b.rs2]) {
@@ -493,12 +493,8 @@ void exec_btype(cpu_state_t *cpu, uint32_t inst, uint8_t *mem) {
 			}
 			cpu->pc = target;
 		}
-	case 0x0:
 	}
 
-	//printf("PC:%d\n", cpu->pc);
-	/**/printf("PC after: %" PRIu32 "\n", cpu->pc);
-
 }
 
 int main() {
@@ -538,46 +534,55 @@ int main() {
 	size_t len = sizeof(arr) / sizeof(arr[0]);
 
 	/* fetch & run */
-	for (size_t i = 0; i < len; i++) {
-		/*printf("\n>");
-		scanf("%s\n", &a);
-		char line[256];
-		int i;
-		if (fgets(line, sizeof(line), stdin)) {
+	size_t i = 0;
+	while (1) {
 
+		printf("\n>");
+		char line[256];
+		if (!fgets(line, sizeof(line), stdin)) {
+			fprintf(stderr, "Error reading interactive input\n");	
+		}
 
-		}*/
+		if (strncmp(line, "s", 1) == 0 || strncmp(line, "step", 4) == 0  ||
+		    strncmp(line, "n", 1) == 0 || strncmp(line, "next", 4) == 0) {
+			if (i >= len) return 0;
 
-		/* execute next instruction */
-		uint32_t inst = arr[i];
+			uint32_t inst = arr[i];
 
-		printf("------------INST%d------\n", i);
-		print_bin32(inst);
-		printf("\n");
+			printf("------------INST%d------\n", i);
+			print_bin32(inst);
+			printf("\n");
 
-		/* decode opcode */
-		uint16_t opcode = inst & 127;
-		printf("opcode: ");
-		print_binless(opcode,7);
-		printf("\n");
+			/* decode opcode */
+			uint16_t opcode = inst & 127;
+			printf("opcode: ");
+			print_binless(opcode,7);
+			printf("\n");
 
-		exec_fn fn = opcode_table[opcode];
+			exec_fn fn = opcode_table[opcode];
 
-		if (!fn) {
-			//illegal(NULL, inst);
-			fprintf(stderr, "Illegal opcode\n");
-			return EXIT_FAILURE;
-		}
+			if (!fn) {
+				//illegal(NULL, inst);
+				fprintf(stderr, "Illegal opcode\n");
+				return EXIT_FAILURE;
+			}
 
-		fn(&cpu,inst,mem);
-		//printf("Memory:\n");
-		//for (int i=0; i<32; i++) {
-		//	printf("0x%x: 0x%x\n", i, mem[i]);
-		//}
+			fn(&cpu,inst,mem);
+			i++;
 
-		printf("Registers:\n");
-		for (int i=0; i<32; i++) {
-			printf("0x%x: 0x%x\n", i, cpu.x[i]);
+		} else if (strncmp(line, "r", 1) == 0 || strncmp(line, "registers", 9) == 0) {
+			printf("Registers:\n");
+			for (int i=0; i<32; i++) {
+				printf("0x%x: 0x%x\n", i, cpu.x[i]);
+			}
+		} else if (strncmp(line, "m", 1) == 0 || strncmp(line, "memory", 6) == 0) {
+			printf("Memory:\n");
+			for (int i=0; i<32; i++) {
+				printf("0x%x: 0x%x\n", i, mem[i]);
+			}
+		} else if (strncmp(line, "ip", 2) == 0 || strncmp(line, "pc", 2) == 0) {
+			printf("Instruction poiter:\n");
+			printf("PC: %" PRIu32 "\n", cpu.pc);
 		}
 	}