started porting simple brainfuck interpreter

6 files changed, 231 insertions, 82 deletions

diff --git a/kernel/kernel.c b/kernel/kernel.c
index 3372b75..34f3d69 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -202,6 +202,10 @@ void kernel_main(uint32_t initial_stack, int mp)
     //
     //
     //vesa_init_doublebuff();
+    
+    // autorun "user-space" prog
+    asm("push $0x80800");
+    asm("ret");
     while(1)
     {
     }
diff --git a/kernel/vesa.c b/kernel/vesa.c
index 7001e02..b0e9885 100644
--- a/kernel/vesa.c
+++ b/kernel/vesa.c
@@ -172,9 +172,15 @@ void PutString(char *str, int x,int y, int color, va_list va)
 
 void PutConsoleChar(char c, int color)
 {
+	if(c=='\n')
+	{
+	    PutConsoleNL();
+	    return;
+	}
 	PutFont(c, console_x*10,console_y*12, color);
 	console_x++;
 
+
 	#ifdef FOOLOS_CONSOLE_AUTOBREAK
 	if(console_x>console_cols)PutConsoleNL();
 	#endif
diff --git a/userspace/Makefile b/userspace/Makefile
index 2a286da..bd1e6ec 100644
--- a/userspace/Makefile
+++ b/userspace/Makefile
@@ -8,7 +8,7 @@ LDFLAGS=-L/home/miguel/temp/fool-os-stuff/newlib-build-clean/i686-elf/newlib/ \
 	-L/home/miguel/temp/fool-os-stuff/newlib-build-clean/i686-elf/libgloss/libnosys/ \
 	-lnosys
 
-all: test.o crt0.o
-	${CC}  -T linker.ld ${LDFLAGS} test.o -Wl,--oformat,binary -o userprog
+all: brainfuck.o crt0.o
+	${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
new file mode 100644
index 0000000..03ce4f5
--- /dev/null
+++ b/userspace/brainfuck.c
@@ -0,0 +1,133 @@
+// taken from: http://it-ride.blogspot.com/2009/11/brainfuck-interpreter.html
+
+/* comment
+ * TODO
+ * You have a bug. You don't check for EOF while looking for square brackets.
+ */
+
+/*
+
+    A brainfuck intepreter written in C, complete with error checking so you
+    don't hurt yourself while, uh, brainfucking. Nothing really special about
+    the implementation and it is probably very poor performance-wise.
+    
+    Author: Felix Oghină
+    License: (brain)fuck licenses!
+
+*/
+
+// ADDED BY FOOLOS : foolos syscalls!
+#include "syscalls.c"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// 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
+
+void usage() {
+    puts(
+        "Usage: brainfuck FILE\n"
+        "If FILE is ommited or is '-', standard input is read"
+    );
+}
+
+int main(int argc, char **argv) {
+
+    // ADDED BY FOOLOS: we will show usage anyway
+     usage();
+
+    // used by the bf program
+    unsigned char *dataptr = malloc(sizeof(char) * DATA_SIZE);
+    // position of the data pointer
+    unsigned int datapos = 0;
+    // input file
+    FILE *input;
+    // level - deepness of brackets
+    // i - uh, you need explanation for this one?
+    unsigned int level, i;
+    // we will read chars from the input into r
+    unsigned char r;
+    
+    // determine input
+    if (argc == 2) {
+        if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-h") == 0) {
+            usage();
+            return EXIT_SUCCESS;
+        }
+        else {
+            input = fopen(argv[1], "r");
+            if (input == NULL) {
+                puts("Error opening input file");
+                return EXIT_FAILURE;
+            }
+        }
+    }
+    else {
+        usage();
+        return EXIT_FAILURE;
+    }
+    
+    // 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);
+        switch(r) {
+        case '>':
+            if (datapos < DATA_SIZE - 1) datapos++;
+            else {
+                puts("brainfuck error: pointer overflow");
+                return EXIT_FAILURE;
+            }
+            break;
+        case '<':
+            if (datapos > 0) datapos--;
+            else {
+                puts("brainfuck error: pointer underflow");
+                return EXIT_FAILURE;
+            }
+            break;
+        case '+':
+            dataptr[datapos]++;
+            break;
+        case '-':
+            dataptr[datapos]--;
+            break;
+        case '.':
+            putchar(dataptr[datapos]);
+            break;
+        case ',':
+            dataptr[datapos] = getchar();
+            break;
+        case '[':
+            if (dataptr[datapos] == 0) {
+                level = 1;
+                while (level != 0) {
+                    r = (unsigned char) fgetc(input);
+                    if (r == '[') level ++;
+                    else if (r == ']') level --;
+                }
+            }
+            break;
+        case ']':
+            if (dataptr[datapos] != 0) {
+                level = 1;
+                while (level != 0) {
+                    fseek(input, -2, SEEK_CUR);
+                    r = (unsigned char) fgetc(input);
+                    if (r == ']') level ++;
+                    else if (r == '[') level --;
+                }
+            }
+            break;
+        }
+    }
+    return EXIT_SUCCESS;
+}
diff --git a/userspace/syscalls.c b/userspace/syscalls.c
new file mode 100644
index 0000000..6547879
--- /dev/null
+++ b/userspace/syscalls.c
@@ -0,0 +1,85 @@
+
+//printf needs following syscalls: sbrk write close fstat isatty lseek read
+//
+
+#include <sys/stat.h>
+
+int close(int file) 
+{
+   return -1;
+}
+
+int fstat(int file, struct stat *st)
+{
+    st->st_mode = S_IFCHR;
+    return 0;
+}
+
+int isatty(int file) {
+    return 1;
+}
+
+int lseek(int file, int ptr, int dir) {
+    return 0;
+}
+
+int read(int file, char *ptr, int len) {
+    return 0;
+}
+    int open(const char *name, int flags, int mode) {
+	            return -1;
+		              }
+
+
+int write(int file, char *ptr, int len) 
+{
+
+    int todo;
+    for (todo = 0; todo < len; todo++) 
+    {
+
+	char byte=(*ptr++);
+        int byt=byte;
+
+	int ebx; // will hold return value;
+	// system call 
+	asm("pusha");
+	asm("mov $61,%eax"); // select syscall)
+
+	asm("mov %0,%%edx"::"m"(byt));
+	//asm("mov $88,%edx");
+
+	asm("int $0x80"); // actual syscall ! interrupt
+        asm("mov %%ebx, %0": "=b" (ebx));
+	asm("popa");
+	//
+	
+    }
+    return len;
+}
+
+caddr_t sbrk(int incr) 
+{
+	    
+//            extern char _end;		/* Defined by the linker */
+	    char _end;
+            static char *heap_end;
+            char *prev_heap_end;
+          
+            if (heap_end == 0) {
+              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;
+}
+
+//
+
diff --git a/userspace/test.c b/userspace/test.c
index bdc6da0..12226d3 100644
--- a/userspace/test.c
+++ b/userspace/test.c
@@ -1,86 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 
-
-//printf needs following syscalls: sbrk write close fstat isatty lseek read
-//
-
-#include <sys/stat.h>
-
-int close(int file) 
-{
-   return -1;
-}
-
-int fstat(int file, struct stat *st)
-{
-    st->st_mode = S_IFCHR;
-    return 0;
-}
-
-int isatty(int file) {
-    return 1;
-}
-
-int lseek(int file, int ptr, int dir) {
-    return 0;
-}
-
-int read(int file, char *ptr, int len) {
-    return 0;
-}
-
-int write(int file, char *ptr, int len) 
-{
-
-    int todo;
-    for (todo = 0; todo < len; todo++) 
-    {
-
-	char byte=(*ptr++);
-        int byt=byte;
-
-	int ebx; // will hold return value;
-	// system call 
-	asm("pusha");
-	asm("mov $61,%eax"); // select syscall)
-
-	asm("mov %0,%%edx"::"m"(byt));
-	//asm("mov $88,%edx");
-
-	asm("int $0x80"); // actual syscall ! interrupt
-        asm("mov %%ebx, %0": "=b" (ebx));
-	asm("popa");
-	//
-	
-    }
-    return len;
-}
-
-caddr_t sbrk(int incr) 
-{
-	    
-//            extern char _end;		/* Defined by the linker */
-	    char _end;
-            static char *heap_end;
-            char *prev_heap_end;
-          
-            if (heap_end == 0) {
-              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;
-}
-
-//
+#include "syscalls.h>
 
 int main()
 {