FAT12: calculating the root directory location
Posted: Tue Jul 18, 2017 1:53 pm
Hi,
I've been following your OS series development.
On "Operating Systems Development - Bootloaders 4" page, under the sections "Step 2: Get start of root directory" and "Root Directory - Complete example",
you show assembly code to calculate the position, as number of sectors, of the FAT12 root directory .
In particular you do:
(number of FATs) * (number of sector per FAT) + (number of reserved sectors)
2 * 9 + 1 = 19
Shouldn't it be:
(number of FATs) * (number of sector per FAT) + (number of reserved sectors) + boot sector
2 * 9 + 1 + 1 = 20
?
Thanks
I've been following your OS series development.
On "Operating Systems Development - Bootloaders 4" page, under the sections "Step 2: Get start of root directory" and "Root Directory - Complete example",
you show assembly code to calculate the position, as number of sectors, of the FAT12 root directory .
In particular you do:
(number of FATs) * (number of sector per FAT) + (number of reserved sectors)
2 * 9 + 1 = 19
Shouldn't it be:
(number of FATs) * (number of sector per FAT) + (number of reserved sectors) + boot sector
2 * 9 + 1 + 1 = 20
?
Thanks