syscalls: improve working with files using vfs

src/fs/vfs.c

@@ -2,8 +2,10 @@
 #include "../include/stdio.h"
 #include "../include/string.h"
 #include "../include/paging.h"
+#include "../include/liballoc.h"
 
-l9660_fs   global_fs;
+l9660_fs*   global_fs;
+l9660_dir*  root_dir;
 
 bool read_sector_callback(l9660_fs *fs, void *buf, uint32_t sector) {
     // The 'fs' parameter is not needed for our simple case, so we can ignore it.
@@ -20,13 +22,26 @@ bool read_sector_callback(l9660_fs *fs, void *buf, uint32_t sector) {
 
 void mount_fs()
 {
-    l9660_status status = l9660_openfs(&global_fs, read_sector_callback);
+    global_fs = malloc(sizeof(l9660_fs));
+
+    l9660_status status = l9660_openfs(global_fs, read_sector_callback);
 
     if (status != L9660_OK) {
         printf("Error opening ISO9660 filesystem!\n");
         return;
     }
     printf("FS mounted\n");
+
+    root_dir = malloc(sizeof(l9660_dir));
+
+    status = l9660_fs_open_root(root_dir, global_fs);
+
+    if(status != L9660_OK)
+    {
+        printf("Error opening root dir\n");
+        return;
+    }
+    printf("root dir opened\n");
 }
 
 void list_files(l9660_dir *dir)
@@ -73,5 +88,33 @@ size_t vfs_read_file(l9660_file *file, uint8_t* buffer)
         total_read += read;
     }
 
+    return total_read;
+}
+
+size_t vfs_read_file_length(l9660_file *file, uint8_t* buffer, size_t length)
+{
+    size_t total_read = 0;
+    l9660_status status;
+
+    while(total_read < length) {
+        char buf[128];
+        size_t to_read = (length - total_read) < 128 ? (length - total_read) : 128;
+        size_t read = 0;
+
+        status = l9660_read(file, buf, to_read, &read);
+
+        if (status != L9660_OK) {
+            printf("An error occurred during file read!\n");
+            break;
+        }
+
+        //check for EOF
+        if (read == 0)
+            break;
+        
+        memcpy(buffer + total_read, buf, read);
+        total_read += read;
+    }
+
     return total_read;
 }