compiler

commit 57175a27ad794a246459b553a67f153384079ed4
parent 87d70f6cf0840c340bf35fe8fc794e2ce1150d85
Author: Brian Swetland <swetland@frotz.net>
Date:   Wed,  4 Mar 2020 16:47:11 -0800

r5e: features!

- make tracing optional (-t)
- allow loading image from file
- provide exit and printhex io devices

Diffstat:
M
src/r5e.c
 | 
48
+++++++++++++++++++++++++++++++++++++++++++-----
M
src/risc5emu.c
 | 
20
+++++++++++++-------
M
src/risc5emu.h
 | 
3
++-
M
src/risc5ins.txt
 | 
1
+

4 files changed, 59 insertions(+), 13 deletions(-)
diff --git a/src/r5e.c b/src/r5e.c
@@ -1,21 +1,59 @@
 #include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
 
 #include "risc5emu.h"
 
 uint32_t data[] = {
-	0x40000030, // mov r0, 0x40
+	0x4000FFD2, // mov r0, 0xFFD2
 	0x51000100, // mov r1, 0xffff0100
 	0xA0100000, // sw r0, [r1, 0]
 	0xE7FFFFFE, // b -3
 };
 
 int main(int argc, char** argv) {
-	risc_t *r = risc_new();
+	bool trace = false;
+	const char* fn = NULL;
 
-	for (unsigned n = 0; n < sizeof(data); n += 4) {
-		risc_store_word(r, n, data[n/4]);
+	while (argc > 1) {
+		if (!strcmp(argv[1], "-t")) {
+			trace = true;
+		} else if (argv[1][0] == '-') {
+			fprintf(stderr, "r5e: unknown option: %s\n", argv[1]);
+			return -1;
+		} else {
+			if (fn != NULL) {
+				fprintf(stderr, "r5e: multiple images not supported\n");
+				return -1;
+			}
+			fn = argv[1];
+		}
+		argc--;
+		argv++;
 	}
 
-	risc_run(r, 100);
+	risc_t *r = risc_new(trace);
+
+	if (fn == NULL) {
+		for (unsigned n = 0; n < sizeof(data); n += 4) {
+			risc_store_word(r, n, data[n/4]);
+		}
+	} else {
+		int fd = open(fn, O_RDONLY);
+		if (fd < 0) {
+			fprintf(stderr, "r5e: cannot open: %s\n", fn);
+			return -1;
+		}
+		unsigned n = 0;
+		uint32_t w;
+		while (read(fd, &w, sizeof(w)) == 4) {
+			risc_store_word(r, n, w);
+			n += 4;
+		}
+		fprintf(stderr,"r5e: loaded %u bytes from '%s'\n", n, fn);
+	}
+
+	risc_run(r, 100000);
 	return 0;
 }
diff --git a/src/risc5emu.c b/src/risc5emu.c
@@ -48,6 +48,7 @@ struct RISC {
 
   uint32_t *RAM;
   uint32_t mem_size;
+  bool TRACE;
 };
 
 enum {
@@ -60,10 +61,11 @@ enum {
 static uint32_t risc_load_io(struct RISC *risc, uint32_t address);
 static void risc_store_io(struct RISC *risc, uint32_t address, uint32_t value);
 
-struct RISC *risc_new() {
+struct RISC *risc_new(bool trace) {
   struct RISC *risc = calloc(1, sizeof(*risc));
   risc->mem_size = DefaultMemSize;
   risc->RAM = calloc(1, risc->mem_size);
+  risc->TRACE = trace;
   risc_reset(risc);
   return risc;
 }
@@ -92,7 +94,7 @@ void risc_single_step(struct RISC *risc) {
     return;
   }
 
-  disasm(risc->PC << 2, ir); 
+  if (risc->TRACE) disasm(risc->PC << 2, ir); 
   risc->PC++;
 
   const uint32_t pbit = 0x80000000;
@@ -289,7 +291,7 @@ void risc_single_step(struct RISC *risc) {
 }
 
 void risc_set_register(struct RISC *risc, int reg, uint32_t value) {
-  printf("                    R%d = 0x%08x\n", reg, value);
+  if (risc->TRACE) printf("                    R%d = 0x%08x\n", reg, value);
   risc->R[reg] = value;
   risc->Z = value == 0;
   risc->N = (int32_t)value < 0;
@@ -310,7 +312,7 @@ uint8_t risc_load_byte(struct RISC *risc, uint32_t address) {
 
 void risc_store_word(struct RISC *risc, uint32_t address, uint32_t value) {
   if (address < risc->mem_size) {
-    printf("                    mem@ 0x%08x = 0x%08x\n", address, value);
+    if (risc->TRACE) printf("                    mem@ 0x%08x = 0x%08x\n", address, value);
     risc->RAM[address/4] = value;
   } else {
     risc_store_io(risc, address, value);
@@ -334,11 +336,15 @@ static uint32_t risc_load_io(struct RISC *risc, uint32_t address) {
 }
 
 static void risc_store_io(struct RISC *risc, uint32_t address, uint32_t value) {
-  printf("                    io@ 0x%08x = 0x%08x\n", address, value);
+  if (risc->TRACE) printf("                    io@ 0x%08x = 0x%08x\n", address, value);
   switch (address - IOStart) {
   case 0x100: {
-    unsigned char x = value;
-    write(1, &x, 1);
+    printf("%08x\nEXIT\n", value);
+    exit(0);
+    break;
+  case 0x104:
+    printf("%08x\n", value);
+    break;
   }
   }
 }
diff --git a/src/risc5emu.h b/src/risc5emu.h
@@ -1,9 +1,10 @@
 
 #include <stdint.h>
+#include <stdbool.h>
 
 typedef struct RISC risc_t;
 
-struct RISC *risc_new();
+struct RISC *risc_new(bool trace);
 
 void risc_reset(struct RISC *risc);
 void risc_run(struct RISC *risc, int cycles);
diff --git a/src/risc5ins.txt b/src/risc5ins.txt
@@ -31,3 +31,4 @@
 1101CCCC--------------------cccc bl%C %c
 1110CCCCBBBBBBBBBBBBBBBBBBBBBBBB b%C %B
 1111CCCCBBBBBBBBBBBBBBBBBBBBBBBB bl%C %B
+-------------------------------- inval