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;
 }

src/kernel/kernel.c

@@ -28,21 +28,14 @@ void apply_pic_masks()
 
 void test_iso9660()
 {
-	l9660_dir  g_root_dir;
 	l9660_file g_test_file;
 
 	l9660_status status;
-    // 2. Open the root directory
-    status = l9660_fs_open_root(&g_root_dir, &global_fs);
-    if (status != L9660_OK) {
-        printf("Error opening root directory!\n");
-        return;
-    }
 
 	printf("Files in root directory:\n");
     for (;;) {
         l9660_dirent *dent;
-        status = l9660_readdir(&g_root_dir, &dent);
+        status = l9660_readdir(root_dir, &dent);
 
         if (dent == NULL || status != L9660_OK) {
             break; // End of directory or error
@@ -58,11 +51,11 @@ void test_iso9660()
 	printf("\nReading content of /TEST.TXT:\n");
 
     // Re-open the root directory to reset its position before searching
-    l9660_fs_open_root(&g_root_dir, &global_fs);
+    l9660_fs_open_root(root_dir, global_fs);
 
 	l9660_dir boot_dir;
 	l9660_dir grub_dir;
-	status = l9660_opendirat(&boot_dir, &g_root_dir, "boot");
+	status = l9660_opendirat(&boot_dir, root_dir, "boot");
 	printf("STATUS %X\n", status);
 	status = l9660_opendirat(&grub_dir, &boot_dir, "grub");
 	printf("STATUS %X\n", status);

src/tasking/exec_from_file.c

@@ -49,13 +49,9 @@ void exec_from_file(const char* filename, const char* dirname)
 
     uint8_t* file;
     l9660_dir dir;
-    l9660_dir root_dir;
     l9660_status status;
 
-    status = l9660_fs_open_root(&root_dir, &global_fs);
-    debug_log("l9660_fs_open_root status: 0x%X\n", status);
-
-    status = l9660_opendirat(&dir, &root_dir, dirname);
+    status = l9660_opendirat(&dir, root_dir, dirname);
     debug_log("l9660_opendirat status: 0x%X\n", status);
 
     //list_files(&dir);

src/tasking/syscalls.c

@@ -6,6 +6,7 @@
 #include "../include/string.h"
 #include "../include/screen.h"
 #include "../include/fat.h"
+#include "../include/vfs.h"
 
 #define STDIN_FILENO 0
 #define STDOUT_FILENO 1
@@ -157,7 +158,8 @@ int sys_read(TrapFrame *tf)
         {
             return -EBADF;
         }
-        return 0;//fat_fread(current->file_descriptors[tf->ebx], (void*)tf->ecx, tf->edx);
+        return vfs_read_file_length(current->file_descriptors[tf->ebx], (uint8_t*)tf->ecx, tf->edx);
+        //return 0;//fat_fread(current->file_descriptors[tf->ebx], (void*)tf->ecx, tf->edx);
     }
 }
 
@@ -208,7 +210,8 @@ int sys_open(TrapFrame *tf)
         //debug_log("\n====i: %X\n", i);
         if(current->file_descriptors[i] == NULL)
         {
-            current->file_descriptors[i] = malloc(sizeof(file_t));  // Kernel malloc
+            current->file_descriptors[i] = (l9660_file*)malloc(sizeof(l9660_file));  // Kernel malloc
+            l9660_openat(current->file_descriptors[i], root_dir, filename);
             //debug_log("\n====FILE_DESCRIPTOR: %X\n", i);
             int result = 0;//fat_fopen(current->file_descriptors[i], filename, mode_str);
             if (result < 0) {