diff options
| author | Marvin Borner | 2020-07-28 22:00:26 +0200 |
|---|---|---|
| committer | Marvin Borner | 2020-07-28 22:00:26 +0200 |
| commit | 44fa7a529656c1ec8a445cac4ee7b40351a7c753 (patch) | |
| tree | a21dfcd91e2a2bc2913848bbd1bca264ce455d0e /src | |
| parent | 7786aca4ebabc78048ca2442b6734e99ba631872 (diff) | |
Make the bin smaller so direct pointers are enough
This is not a final sollution but will work for the moment. I'm just too
confused by assembly so I implemented some tricks to shrink the binary.
Diffstat (limited to 'src')
| -rw-r--r-- | src/entry.asm | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/src/entry.asm b/src/entry.asm index 4b8b247..5fdf4c2 100644 --- a/src/entry.asm +++ b/src/entry.asm @@ -311,8 +311,9 @@ kernel_load: xor ax, ax ; Clear ax mov dx, ax ; Clear dx - cmp cx, EXT2_DIRECT_POINTER_COUNT ; Indirect pointer needed? - jge .indirect ; Singly indirect pointer + ; TODO: Add singly pointer support (until ~12KiB) + ;cmp cx, EXT2_DIRECT_POINTER_COUNT ; Indirect pointer needed? + ;jge .indirect ; Singly indirect pointer mov ax, [di] ; Set ax = block pointer shl ax, 1 ; Multiply ax by 2 @@ -328,22 +329,23 @@ kernel_load: xor ebx, ebx + ; Read singly indirect pointer mov bx, EXT2_GET_ADDRESS(EXT2_KERNEL_INODE) ; First block lea di, [bx + EXT2_IND_POINTER_OFFSET] ; Address of singly indirect pointer mov bx, 0x3000 ; Arbitrary address - mov ax, [di] ; Set ax = block pointer shl ax, 1 ; Multiply ax by 2 mov [lba], ax mov [dest], bx call disk_read + ; Read data sub cx, EXT2_DIRECT_POINTER_COUNT lea di, [ebx + 4 * ecx] mov bx, 0x4000 ; Arbitrary address - mov ax, [di] shl ax, 1 + ;sub bx, 0x400 mov [lba], ax mov [dest], bx call disk_read |