Completed FAT12 structures, added some for VFS.

[BOS.git] / kernel / vfs / vfs.asm

diff --git a/kernel/vfs/vfs.asm b/kernel/vfs/vfs.asm
index ff661fd2ef8e3004a0a9240f761fc2a85f9394a9..30d5590c39e0f5c6f6593c9d2a8d4674ce44db6f 100644 (file)
--- a/kernel/vfs/vfs.asm
+++ b/kernel/vfs/vfs.asm
@@ -2,12 +2,138 @@
 ; BOS kernel                Christoffer Bubach, 2012-2015. ;
 ;----------------------------------------------------------;
 ;                                                          ;
 ; BOS kernel                Christoffer Bubach, 2012-2015. ;
 ;----------------------------------------------------------;
 ;                                                          ;

-;        VFS  handling all devices and filesystems.        ;
+;        VFS handling all devices and filesystems.         ;

 ;                                                          ;
 ;----------------------------------------------------------;
 
 ;                                                          ;
 ;----------------------------------------------------------;
 

+
+    ; file handles need to be dword, where the high
+    ; word contains drive number, and the low word
+    ; is the drive/FS specific handle. limits FS to
+    ; a max of 65535 opened files. should be alright. ;)
+
+
+    ;---------------------------------------------;
+    ;   VFS main structure                        ;
+    ;---------------------------------------------;
+    struc VFS
+    {
+        .number:                times 255      db 0   ; 00=FD, 0x10=HD, 0x60=CD, 0x80=VD, 90=RD, B0=ND
+        .storage:
+            times 255 * sizeof.VFS_storage     db 0   ; storage driver structure
+        .filesystem:          
+            times 255 * sizeof.VFS_filesystem  db 0   ; filesystem driver structure
+        .mounted                               db 0   ; 1/0 switch if mounted
+        .current_path:          times 255      db 0   ; drive opened path (increase max path size?)
+    }
+
+    virtual at 0                                      ; could use "at esi" instead
+        VFS VFS
+        sizeof.VFS = $-$$     
+    end virtual
+
+    ;---------------------------------------------;
+    ;   VFS storage driver structure              ;
+    ;---------------------------------------------;
+    struc VFS_storage
+    {
+        .data_pointer         dd  0                   ; internal driver data
+        .init                 dd  0                   ; pointer to init
+        .deinit               dd  0                   ; remove driver
+        .read                 dd  0                   ; read device
+        .write                dd  0                   ; write device
+        .ioctl                dd  0                   ; handle device specific extras
+    }
+
+    virtual at 0
+        VFS_storage VFS_storage
+        sizeof.VFS_storage = $-$$
+    end virtual
+
+    ;---------------------------------------------;
+    ;   VFS filesystem structure                  ;
+    ;---------------------------------------------;
+    struc VFS_filesystem
+    {
+        .data_pointer         dd  0                   ; internal driver data
+        .init                 dd  0                   ; pointer to init
+        .deinit               dd  0                   ; remove driver
+        .format               dd  0                   ; format drive
+        .mount                dd  0                   ; mount drive
+        .unmount              dd  0                   ; unmount drive
+        .find                 dd  0                   ; find file
+        .findnext             dd  0                   ; get next match
+        .open                 dd  0                   ; open file, get handle
+        .read                 dd  0                   ; read file from handle
+        .write                dd  0                   ; write file from handle
+        .seek                 dd  0                   ; seek from handle
+        .remove               dd  0                   ; remove file/dir
+        .create               dd  0                   ; create file/dir
+        .ioctl                dd  0                   ; extra calls if exists
+    }
+
+    virtual at 0
+        VFS_filesystem VFS_filesystem
+        sizeof.VFS_filesystem = $-$$
+    end virtual
+
+    ;---------------------------------------------;
+    ;   VFS structure pointer                     ;
+    ;---------------------------------------------;
+    VFS_structure             dd 0
+
+
+;--------------------------------------------------------------;
+;   init_vfs  -  detect connected drives                       ;
+;--------------------------------------------------------------;
+;                                                              ;
+;       out:                    cf = set if failed             ;
+;                                                              ;
+;--------------------------------------------------------------;

 init_vfs:
         push   eax
 init_vfs:
         push   eax

-        ; a bit more code here 
+        push   ebx
+
+        mov    ebx, sizeof.VFS                        ; allocate structure size
+        call   allocate_mem
+        cmp    eax, 0
+        jne    .ok
+        stc                                           ; if error, set carry
+        mov    ebx, 0
+
+    .ok:
+        mov    dword [VFS_structure], ebx
+
+        pop    ebx
+        pop    eax
+        ret
+
+;--------------------------------------------------------------;
+;   add_media  -  add media driver                             ;
+;--------------------------------------------------------------;
+;                                                              ;
+;       in:  reg = pointer to VFS drive info                   ;
+;                                                              ;
+;       out: reg = pointer to struct(s) if FAT12 found         ;
+;                                                              ;
+;--------------------------------------------------------------;
+add_media:
+        push   eax
+        ;...
+        pop    eax
+        ret
+
+;--------------------------------------------------------------;
+;   add_fs  -  add filesystem driver                           ;
+;--------------------------------------------------------------;
+;                                                              ;
+;       in:  reg = pointer to VFS drive info                   ;
+;                                                              ;
+;       out: reg = pointer to struct(s) if FAT12 found         ;
+;                                                              ;
+;--------------------------------------------------------------;
+add_fs:
+        push   eax
+        ;...

         pop    eax
         ret
\ No newline at end of file
         pop    eax
         ret
\ No newline at end of file