@@ -5,6 +5,18 @@ #include <stdint.h>
 
 #include "cedos/mm/paging.h"
 
+typedef uint32_t fpos_t;
+
+typedef struct {
+    enum {
+        FILE_STDIO = 0,
+        FILE_FAT = 1
+    } type;
+    uint32_t stdio_id;
+    uint32_t fat_cluster;
+    fpos_t pos;
+} FILE;
+
 int file_open(const char *pathname, int flags);
 int file_openat(int fd, const char *fname, int flags);
 int file_read(int fd, char *buffer, uint32_t size);

@@ -112,7 +112,7 @@ > $(RM) -r $(CURRENT_DIR)/build/* 2> /dev/null; true
 
 .PHONY: run
 run:
-> ./run.sh
+> ./run.sh $(GLOBAL_BUILD)/cedos.img
 
 .PHONY: docs
 docs:

@@ -1,1 +1,1 @@
-qemu-system-i386 -drive index=0,if=floppy,format=raw,file=./build/release/cedos.img -m 64 -monitor stdio -no-reboot -d int,cpu_reset,exec,in_asm -vga std -vnc :0 2> log/run_err.log
+qemu-system-i386 -drive index=0,if=floppy,format=raw,file=${1} -m 64 -monitor stdio -no-reboot -d int,cpu_reset,exec,in_asm -vga std -vnc :0 2> log/run_err.log

@@ -129,6 +129,8 @@ PRINT_DBG("Loading ELF executable \"%s\".\n", fname);
     VIRT_ADDR elf_addr = (VIRT_ADDR*)(0xA0000000);
     // TODO: needs to change when we have other file systems
     int fd = file_open(fname, 0);
+    PRINT_DBG("File handle: %i\n", fd);
+    
     if (fd == -1) {
         printk("Executable file not found: %s\n", fname);
         return -1;

@@ -1,5 +1,8 @@
 #include "cedos/fat.h"
+#include "cedos/file.h"
 #include "string.h"
+#include "assert.h"
+
 #include <stdint.h>
 
 typedef struct {
@@ -196,15 +199,11 @@ return low | high;
     }
 }
 
-int FAT_openat(int fd, const char *fname, int flags) {
+int FAT_openat(FILE *root, FILE *handle, const char *fname, int flags) {
     int i = 0;
 
     // TODO: take fd into consideration (open file in that subdirectory)
-    
-    
-    if (!(fd & 0x1000)) { return -1; }
-
-    fd &= 0x0FFF;
+    assert(root->type == FILE_FAT);
 
     uint16_t first_cluster;
     while (1) {
@@ -216,15 +215,17 @@ if (i <= 0) { return -1; }
 
         if (strcmp(buffer, fname) == 0) {
             // file found
-            return first_cluster | 0x1000;
+            handle->type = FILE_FAT;
+            handle->fat_cluster = first_cluster;
+            return 0;
         }
     }
 }
 
-uint32_t FAT_read(int fd, void *buffer, int count) {
-    if (!(fd & 0x1000)) { return -1; }
+uint32_t FAT_read(FILE *file, void *buffer, int count) {
+    assert(file->type == FILE_FAT);
     
-    uint16_t cluster = fd & 0xFFF;
+    uint16_t cluster = file->fat_cluster;
     uint32_t size = 0;
 
     while (1) {

@@ -4,28 +4,72 @@
 #include "cedos/drivers/console.h"
 #include "cedos/drivers/keyboard.h"
 
-const int root_fd = 0x1000;
+#ifdef DEBUG
+#define PRINT_DBG(...) printk("[" __FILE__ "] " __VA_ARGS__)
+#else
+#define PRINT_DBG(...) {}
+#endif
+
+//const int root_fd = 0x1000;
+
+FILE file_table[256];
+int next_free = 0;
+
+int stdin, stdout, fat_root;
+
+int file_init() {
+    file_table[next_free].type = FILE_STDIO;
+    file_table[next_free].stdio_id = 0;
+    file_table[next_free].fat_cluster = 0;
+    stdin = next_free++;
+
+    file_table[next_free].type = FILE_STDIO;
+    file_table[next_free].stdio_id = 1;
+    file_table[next_free].fat_cluster = 0;
+    stdout = next_free++;
+
+    // FAT root
+    file_table[next_free].type = FILE_FAT;
+    file_table[next_free].stdio_id = 0;
+    file_table[next_free].fat_cluster = 0;
+    fat_root = next_free++;
+
+    return 0;
+}
 
 int file_open(const char *pathname, int flags) {
     while (*pathname == '/') {
         pathname++;
     }
 
-    return file_openat(0x1000, pathname, flags);
+    return file_openat(fat_root, pathname, flags);
 }
 
 int file_openat(int fd, const char *fname, int flags) {
-    if (fd & 0x1000) {
-        return FAT_openat(fd, fname, flags);
+    int new_fd = next_free++;
+
+    PRINT_DBG("Given fd: %i\n", fd);
+    PRINT_DBG("New fd:   %i\n", new_fd);
+
+    FILE *root = &file_table[fd];
+    FILE *handle = &file_table[new_fd];
+
+    if (root->type == FILE_FAT) {
+        PRINT_DBG("fd is FAT\n");
+        FAT_openat(root, handle, fname, flags);
+        return new_fd;
     } else {
+        PRINT_DBG("fd is NOT FAT (%i)\n", (int)(root->type));
         // open other files
         return 0;
     }
 }
 
 int file_read(int fd, char *buffer, uint32_t size) {
-    if (fd & 0x1000) {
-        return FAT_read(fd, buffer, size);
+    FILE *file = &file_table[fd];
+
+    if (file->type == FILE_FAT) {
+        return FAT_read(file, buffer, size);
     } else {
         uint32_t i = 0;
         while (i < size) {

@@ -16,6 +16,7 @@ #include "cedos/core.h"
 
 #include "cedos/elf.h"
 
+#include "cedos/file.h"
 #include "cedos/fat.h"
 
 #include "linker.h"
@@ -65,7 +66,11 @@ printk("Initializing keyboard...");
     ps2_kb.init();
     printk("done.\n");
 
-    printk("Initializing root file system...");
+    printk("Initializing files...");
+    file_init();
+    printk("done.\n");
+
+    printk("Initializing FAT file system...");
     FAT_init();
     printk("done.\n");