6502: get examples to work

libb/6502-posix.b

@@ -1,13 +1,53 @@
 exit(code) {
-    0(code);
+    (*0xFFFC)(code);
 }
-
 abort() {
     exit(69);
 }
+assert(cond, msg) {
+    if (cond == 0) {
+        printf("Assertion failed: %s\n", msg);
+        abort();
+    }
+}
 
+/* not correct at all */
+usleep(n) {
+    auto i, j;
+    if (n < 0) n = 32767;
+    i = 0; while (i < n>>2) {
+        __asm__("nop");
+        i++;
+    }
+}
+
+/* IO functions */
 putchar(c) {
-    0xFFEF(c);
+    extrn lchar;
+    lchar(0xD012, 0, c);
+}
+
+getchar() {
+    extrn char;
+    return (char(0xD010, 0));
+}
+
+read(fd, buf, n) {
+    extrn lchar;
+    auto i, c;
+
+    assert(fd == 0, "only fd==0 supported for read");
+    i = 0; while (i < n) {
+        c = getchar();
+        lchar(buf, i, c);
+        if (c == '\n') {
+            return (n); /* simulate terminal behaviour */
+        }
+        if (c == 0xFF) return (i);
+        i++;
+    }
+
+    return (n);
 }
 
 char __asm__(
@@ -43,76 +83,7 @@ lchar __asm__(
 fputc(c, fd) {
     putchar(c);
 }
-
-/* TODO: actually allocate something */
-__heap_ptr 0x0200;
-malloc(size) {
-    extrn printf;
-    auto ptr;
-    ptr = __heap_ptr;
-    __heap_ptr += size;
-    if (__heap_ptr >= 0x1000) {
-        printf("Allocation reached end: %p\nTODO: allow allocating more, implement free\n", __heap_ptr);
-        abort();
-    }
-    return (ptr);
-}
-/* TODO: free someting? */
-realloc(ptr, size) {
-    return (malloc(size));
-}
-
-/* TODO: Try to implement this function with assembly
-   Problem with this implementation is that it is not
-   mapped to the operator
-   We cannot call this function `div` as it conflicts
-   with the `divmod` test
-*/
-_div(a, b) {
-    auto d, sign;
-    sign = 0;
-    if (a < 0) {
-        sign = !sign;
-        a = -a;
-    }
-    if (b < 0) {
-        sign = !sign;
-        b = -a;
-    }
-
-    d = 0; while(a >= b) {
-        a = a - b;
-        d++;
-    }
-    if (sign) d = -d;
-    return (d);
-}
-_udiv(a, b) {
-    auto d;
-    d = 0; while(a >= b | a < 0) {
-        a = a - b;
-        d++;
-    }
-    return (d);
-}
-
-/* TODO: Try to implement this function with assembly
-   Problem with this implementation is that it is not
-   mapped to the operator */
-_rem (a, b) {
-    auto d;
-    while(a >= b) {
-        a = a - b;
-    }
-    return (a);
-}
-_urem(a, b) {
-    auto d;
-    while(a >= b | a < 0) {
-        a = a - b;
-    }
-    return (a);
-}
+fflush(); /* nop */
 
 printn(n, b, sign) {
     auto a, c, d, __div, __rem;
@@ -133,7 +104,17 @@ printn(n, b, sign) {
     putchar(c);
 }
 
+stdin 0;
+stdout 1;
+stderr 1;
+
+fprintf(fd, str, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15) {
+    assert((fd == 1) | (fd == 2), "only fd in [1,2] supported for fprintf");
+    return (printf(str, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15));
+}
+
 printf(str, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15) {
+    extrn char;
     auto i, j, arg, c;
     i = 0;
     j = 0;
@@ -143,7 +124,7 @@ printf(str, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15) {
     c = char(str, i);
     while (c != 0) {
         if (c == '\n') {
-            putchar(0xD); // \r
+            putchar(0xD); /* \r */
         }
 
         if(c == '%') {
@@ -164,9 +145,9 @@ printf(str, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15) {
                 while (c = char(*arg, j++)) {
                     putchar(c);
                 }
-            } else if (c == 'z' | c == 'l') { /* hack for %zu %lu, % */
+            } else if ((c == 'z') | (c == 'l')) { /* hack for %zu %lu, % */
                 c = '%';
-                goto while_end;
+                goto continue;
             } else {
                 putchar('%');
                 arg += 2; /* word size */
@@ -177,10 +158,91 @@ printf(str, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15) {
         }
         i++;
         c = char(str, i);
-        while_end:;
+        continue:;
+    }
+}
+
+/* Math functions */
+_rand_seed 123456789;
+rand() {
+    _rand_seed = 20077 * _rand_seed + 12345;
+    return (_rand_seed);
+}
+
+atoi(str) {
+    extrn char;
+
+    auto i, c, n, neg;
+    neg = 0;
+    n = 0;
+
+    if (char(str, 0) == '-') {
+        neg = 1;
+        str++;
+    }
+
+    i = 0; while (1) {
+        c = char(str, i);
+        if ((c == 0) | (c < '0') | (c > '9')) goto end;
+        n = n * 10 + (c - '0');
+        i++;
     }
+
+    end:;
+    if (neg) n = -n;
+
+    return (n);
 }
 
+/* TODO: Try to implement this function with assembly
+   Problem with this implementation is that it is not
+   mapped to the operator
+   We cannot call this function `div` as it conflicts
+   with the `divmod` test
+*/
+_div(a, b) {
+    auto d, sign;
+    sign = 0;
+    if (a < 0) {
+        sign = !sign;
+        a = -a;
+    }
+    if (b < 0) {
+        sign = !sign;
+        b = -a;
+    }
+
+    d = 0; while(a >= b) {
+        a = a - b;
+        d++;
+    }
+    if (sign) d = -d;
+    return (d);
+}
+_udiv(a, b) {
+    auto d;
+    d = 0; while(a >= b | a < 0) {
+        a = a - b;
+        d++;
+    }
+    return (d);
+}
+
+/* TODO: Try to implement this function with assembly
+   Problem with this implementation is that it is not
+   mapped to the operator */
+_rem (a, b) {
+    return (a - a / b * b);
+}
+_urem(a, b) {
+    auto d;
+    while(a >= b | a < 0) {
+        a = a - b;
+    }
+    return (a);
+}
+
+/* memory related functions */
 strlen(s) {
     auto n;
     n = 0;
@@ -194,7 +256,6 @@ toupper(c) {
 }
 
 
-/* memory related functions */
 memset(addr, val, size) {
     extrn lchar;
     auto i;
@@ -204,3 +265,42 @@ memset(addr, val, size) {
         i += 1;
     }
 }
+
+memcpy(dest, src, n) {
+    extrn char, lchar;
+    auto i, rn;
+    rn = n;
+    if (n & 1) n--;
+
+    i = 0; while (i < n) {
+        dest[i] = src[i];
+        i++;
+    }
+
+    if (rn & 1) lchar(dest, n-1, char(src, n-1));
+    return (dest);
+}
+
+/* TODO: actually allocate something */
+__heap_ptr 0x0E000;
+malloc(size) {
+    extrn printf;
+    auto ptr;
+    ptr = __heap_ptr;
+    __heap_ptr += size;
+    if (__heap_ptr >= 0xFF00) {
+        printf("Allocation reached end: %p\nTODO: allow allocating more, implement free\n", __heap_ptr);
+        abort();
+    }
+    return (ptr);
+}
+free() {
+    /* TODO: free someting */
+}
+realloc(ptr, size) {
+    auto nptr;
+    nptr = malloc(size);
+    memcpy(nptr, ptr, size);
+    free(ptr);
+    return (nptr);
+}