nightloader/code/legacy-bios/bootsector/fat32.asm

; TODO: Read FAT32 filesystem and load raw binary from path nightloader/stage_2.bin

FAT32_HEADER_ROOT_DIRECTORY_FAT_INDEX equ 0x2c

find_stage_2:
    
    ; Set extra-segment to the address where the Stage 2 - partition is located.
    mov bx, 0x2000
    mov es, bx
    mov ds, bx
    
    
    
    ; PART 1: FIND THE STAGE 2 - FILE'S OFFSET IN THE PARTITION
    
    ; Read cluster size (in bytes) into dx
    mov bx, 0x000b
    mov ax, [bx]
    add bx, 2
    mov di, [bx]
    mul di
    mov dx, ax
    
    ; Read the root directory's first cluster's index into si:di (si: upper, di: lower)
    mov bx, FAT32_HEADER_ROOT_DIRECTORY_FAT_INDEX
    mov di, [bx]
    add bx, 2
    mov si, [bx]
    
    push si
    push di
    
    ; Put address of root directory into ds:bx
    
    ; Part 1: Get the overflow
    ; mov bx, 
    
    
    
    
    ; Loop through the root directory's entries
.root_directory_loop: ; Loops through all the root directory's clusters
    
    mov di, [bx]
    add bx, 2
    mov si, [bx]
    
    
    
    ; Test for the root directory's "Last Cluster" - marker.
    mov ax, [bx]
    ; cmp 
    jmp .root_directory_loop

; Arguments:
;   bx: 
; Return Values:
;   ax: The index of the FAT-entry in which the searched file was found.
find_file_in_directory: