diff options
| author | Marvin Borner | 2020-06-24 19:48:51 +0200 |
|---|---|---|
| committer | Marvin Borner | 2020-06-24 19:48:51 +0200 |
| commit | 4f04cebd979b7d9ef1a814b10a6769831cf8b7d4 (patch) | |
| tree | 972d83ecc221a60d2dc2c7ce12c99894a2d8fad8 | |
| parent | 0757cb78e43963ef73f4cf5a3cff842f19546af1 (diff) | |
Cleaned up boot-loop
Pun intended.
| -rw-r--r-- | src/entry.asm | 42 |
1 files changed, 16 insertions, 26 deletions
diff --git a/src/entry.asm b/src/entry.asm index 0fa8c17..4ab54ac 100644 --- a/src/entry.asm +++ b/src/entry.asm @@ -114,6 +114,7 @@ disk_success_msg db "Disk is valid", NEWLINE, RETURN, NULL inode_table_msg db "Found inode table", NEWLINE, RETURN, NULL boot_dir_msg db "Found boot directory", NEWLINE, RETURN, NULL boot_dir_name db "boot", NULL +boot_dir_name_len equ $ - boot_dir_name drive db 0 ; Data @@ -158,20 +159,13 @@ stage_two: call print ; Load root dir - xor bx, bx - mov ax, bx mov bx, EXT2_ROOT_DIR ; First block mov ax, [bx + EXT2_TYPE_OFFSET] ; Filetype - and ax, EXT2_DIR ; Check if directory - cmp ax, EXT2_DIR - jne disk_error + and ax, EXT2_DIR ; AND with directory + cmp ax, EXT2_DIR ; Check if it's a directory + jne disk_error ; Not a directory! mov cx, [bx + EXT2_COUNT_OFFSET] ; Number of sectors for inode - lea di, [bx + EXT2_POINTER_OFFSET] ; Address of first block pointer - - ; Find kernel - xor ax, ax - mov dx, ax - mov ax, [di] + mov ax, [bx + EXT2_POINTER_OFFSET] ; Address of first block pointer mov dx, 2 mul dx mov [lba], ax @@ -179,25 +173,21 @@ stage_two: mov [dest], bx call disk_read - ; TODO: Clean up - remove debug things - mov cx, bx + ; TODO: Fix endless loop when not found + ; Find boot directory .file_loop: + mov si, bx ; First comparison string + add si, EXT2_FILENAME_OFFSET ; Set pointer to filename + mov di, boot_dir_name ; Second comparison string + mov cx, boot_dir_name_len ; String length + rep cmpsb ; Compare strings + je .found_boot ; Found correct dirent! + add bx, [bx + EXT2_ENTRY_LENGTH_OFFSET] ; Add dirent struct size + jmp .file_loop ; Jump to next dirent! - push cx - mov si, cx - add si, EXT2_FILENAME_OFFSET - mov di, boot_dir_name - mov cx, 5 - rep cmpsb - je .found_boot - pop cx - - mov bx, cx - add cx, [bx + EXT2_ENTRY_LENGTH_OFFSET] - jmp .file_loop .found_boot: mov si, boot_dir_msg - call print + call print ; Show happy message! jmp $ mov bx, 0x5000 |