ported Brainfuck interpreter.

3 files changed, 90 insertions, 24 deletions

diff --git a/userspace/Makefile b/userspace/Makefile
index bd1e6ec..21c4560 100644
--- a/userspace/Makefile
+++ b/userspace/Makefile
@@ -9,6 +9,6 @@ LDFLAGS=-L/home/miguel/temp/fool-os-stuff/newlib-build-clean/i686-elf/newlib/ \
 	-lnosys
 
 all: brainfuck.o crt0.o
-	${CC}  -T linker.ld ${LDFLAGS} brainfuck.o -Wl,--oformat,binary -o userprog
+	${CC}  -T linker.ld ${LDFLAGS} brainfuck.o -Wl,--oformat,binary  -o userprog
 clean:
 	-rm *.o *.out userprog
diff --git a/userspace/brainfuck.c b/userspace/brainfuck.c
index 03ce4f5..c363693 100644
--- a/userspace/brainfuck.c
+++ b/userspace/brainfuck.c
@@ -25,7 +25,7 @@
 
 // by brainfuck standards (doesn't that sound funny?), the data pointer has
 // 30,000 bytes at its disposal, but I hate hard-coding such stuff.
-#define DATA_SIZE 30000
+#define DATA_SIZE 3000
 
 void usage() {
     puts(
@@ -34,13 +34,14 @@ void usage() {
     );
 }
 
-int main(int argc, char **argv) {
-
-    // ADDED BY FOOLOS: we will show usage anyway
-     usage();
+int main(int argc, char **argv) 
+{
+    //added by FOOLOS
+    syscalls_init();
 
     // used by the bf program
     unsigned char *dataptr = malloc(sizeof(char) * DATA_SIZE);
+
     // position of the data pointer
     unsigned int datapos = 0;
     // input file
@@ -51,6 +52,8 @@ int main(int argc, char **argv) {
     // we will read chars from the input into r
     unsigned char r;
     
+    /* uncommented by FOOLOS 
+     
     // determine input
     if (argc == 2) {
         if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-h") == 0) {
@@ -69,16 +72,26 @@ int main(int argc, char **argv) {
         usage();
         return EXIT_FAILURE;
     }
-    
+
+    */
+
+    // added by FOOLOS
+    input=fopen(1,"r");
+    puts("Welcome to the BRAINFUCK by Felix Oghina");
+    puts("Compiled for FoolOS");
+    printf("dataptr: 0x%08X\n",dataptr);
+
     // zero the data pointer
     for (i=0; i < DATA_SIZE; i++) {
         dataptr[i] = 0;
     }
-    
+
     // start interpreting
     rewind(input);
+
     while (!feof(input)) {
         r = (unsigned char) fgetc(input);
+//	printf("%c",r);
         switch(r) {
         case '>':
             if (datapos < DATA_SIZE - 1) datapos++;
@@ -129,5 +142,6 @@ int main(int argc, char **argv) {
             break;
         }
     }
+    puts("brainfuck: finishing!");
     return EXIT_SUCCESS;
 }
diff --git a/userspace/syscalls.c b/userspace/syscalls.c
index 6547879..d8a463d 100644
--- a/userspace/syscalls.c
+++ b/userspace/syscalls.c
@@ -1,39 +1,79 @@
-
 //printf needs following syscalls: sbrk write close fstat isatty lseek read
 //
 
 #include <sys/stat.h>
+#include <string.h>
+
+static int preread;
+static int alloc;
+easywrite(char *c);
+
+void syscalls_init()
+{
+    preread=0;
+    alloc=0xff0000;
+}
 
 int close(int file) 
 {
-   return -1;
+    easywrite("syscall: close\n");
+    return -1;
 }
 
 int fstat(int file, struct stat *st)
 {
+//    easywrite("syscall: fstat\n");
     st->st_mode = S_IFCHR;
     return 0;
 }
 
-int isatty(int file) {
+int isatty(int file) 
+{
+    easywrite("syscall: isatty\n");
     return 1;
 }
 
-int lseek(int file, int ptr, int dir) {
-    return 0;
+int lseek(int file, int ptr, int dir) 
+{
+//    printf("syscall: lseek %i %i %i",file,ptr,dir);
+    if(dir==0)preread=ptr;
+    else{ puts("other modes unsupported sorry"); while(1);}
+    return preread;
 }
 
-int read(int file, char *ptr, int len) {
-    return 0;
+
+
+int read(int file, char *ptr, int len)
+{
+//    easywrite("syscall: read\n");
+
+    int i;
+    char buf[]="++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.";
+
+    if(preread>=strlen(buf)){
+	easywrite("syscall: read = EOF\n");
+	while(1);
+	return 0; //EOF
+    }
+
+    for(i=0;i<len;i++)
+    {
+	if(preread>=strlen(buf))return i;
+	ptr[i]=buf[preread++];
+    }
+
+    return len;
 }
-    int open(const char *name, int flags, int mode) {
-	            return -1;
-		              }
 
+int open(const char *name, int flags, int mode)
+{
+    easywrite("syscall: open\n");
+    return 99;
+    return -1;
+}
 
 int write(int file, char *ptr, int len) 
 {
-
     int todo;
     for (todo = 0; todo < len; todo++) 
     {
@@ -58,28 +98,40 @@ int write(int file, char *ptr, int len)
     return len;
 }
 
+
+
 caddr_t sbrk(int incr) 
 {
+	    easywrite("syscall: sbrk!!\n");
+	    int oldalloc=alloc;
+	    alloc+=incr;
+	    return oldalloc;
+	    /*
 	    
-//            extern char _end;		/* Defined by the linker */
-	    char _end;
+            extern char end;	    
+//	    char _end;
             static char *heap_end;
             char *prev_heap_end;
           
             if (heap_end == 0) {
-              heap_end = &_end;
+              heap_end = &end;
             }
             prev_heap_end = heap_end;
-	    /*
+
             if (heap_end + incr > stack_ptr) {
               write (1, "Heap and stack collision\n", 25);
               abort ();
             }
-	    */
           
             heap_end += incr;
             return (caddr_t) prev_heap_end;
+	    */
 }
 
 //
 
+// helpers
+easywrite(char *c)
+{
+    write(1,c,strlen(c));
+}