Ошибка при создании загрузочной дискеты, содержащей загрузчик и ядро ​​

Question

Я пытаюсь создать загрузочный флоппи-диск для файлов boot.bin и kernel.bin. Мой boot.asm код:

bits 16 

section .text 
start:   
JMP MAIN 

WAIT_FOR_KEY: 
MOV AH, 00H 
INT 16H 
RET 

CLEAR: 
MOV AH, 0H      ;CHANGING THE VIDEO MODE TO CLEAR THE SCREEN 
MOV AL, 03H      ;VIDEO MODE COD 
INT 10H 
RET 

LOG_TO_HTS: 
PUSH BX 
PUSH AX 
MOV BX, AX 
MOV DX, 0 
DIV WORD[ALL_SECTORS] 
ADD DL, 01H 
MOV CL, DL 
MOV AX, BX 
MOV DX, 0 
DIV WORD [ALL_SECTORS] 
MOV DX, 0 
DIV WORD[FACES] 
MOV DH, DL 
MOV CH, AL 
POP AX 
POP BX 
MOV DL, BYTE [BOOT_DEVICE] 
RET 

ECHO:     ;-=-=-=PRINTING FUNCTION =-=-=-; 
LODSB     ;MOV ONE CHAR FROM SI TO AL AND DELETE IT FROM SI 
CMP AL, 0    ;CHECK IF THE VALUE IN AL=0, IF ITS ZERO THEN WE 
JE DONE     ;WE ARE DONE PRINTING, AND JUMP BACK TO THE MAIN FUNCTION 
CMP AL, 59 
JE NEWLINE 
MOV AH, 0EH    ;THE FUNCTION CODE FOR PRINTING (TELETYPE PRINTING) 
INT 10H     ;BIOS CALL 
JMP ECHO    ;IF WE ARRIVED TO THIS LINE THATS MEAN WE ARE NOT DONE WITH 
         ;PRINTING THE WHOLE STREING SO JUMP BACK AND COMPLETE THE PROCESS 

DONE:     ;LABEL CONTAINS ONE INSTRUCTION TO JUMP BACK TO THE LINE 
RET      ;WHERE WE CALLED THE ECHO FUNCTION 

NEWLINE: 
PUSHA 
MOV AH, 0EH 
MOV AL, 13 
INT 10H 
MOV AL, 10 
INT 10H 
POPA 
RET 

RESET_DRIVE:        ;RESET FLOPPY DRIVE FUNCTION 
MOV AX, 0       ;THE FUNCTION CODE TO RESET DRIVE 
MOV DL, BYTE [BOOT_DEVICE]       ;DRIVE ID TO RESET 
INT 13H 
RET 


MAIN:       ;THE MAIN FUNCTION LABEL 


;TO BEGIN LOADING EXTERNAL FILE LIKE KERNEL SOME THINGS MUST BE DONE LIKE : 
;1- SETTING UP THE STACK 
;2- SETTING UP THE SEGMENTS 
;3- SPECIFY THE BOOT DRIVE 

;SETTING UP THE STACK 
CLI        ;CLEAR INTERRUPTS TO SET THE SEGMENT 

XOR AX, AX      ;SET THE BOTTOM OF THE STACK 
MOV SS, AX 
MOV SP, 0XFFFF     ;SET THE TOP OF THE STACK 
STI        ;RESTORE THE INTERRUPTS 

;SETTING UP THE SEGMENTS 
MOV AX, 07C0H 
MOV DS, AX 
MOV ES, AX 
;AFTER SETTING UP SEGMENTS AND STACK, YOU ARE FREE TO CODE WHAT EVER YOU WANT 
;THE CPU WILL RECOGNISE YOUR CODE AS A BOOTLOADER 

CALL CLEAR 
;MOV SI, WELCOME_MSG 
;CALL ECHO 


MOV [BOOT_DEVICE], DL   ;SAVE THE DRIVE ID TO USE IT LATER 


;WE WILL USE IN 13H TO LOAD ROOT DIR. THAT WE NEED TO LOAD THE FIRST SECTOR OF THE KERNEL 
;THEN WE WILL LOAD FAT TO LOAD THE WHOLE KERNEL SINCE THE FILE LOAD PROCESS CONSISTS OF 3 STEPS 
;1- LOAD THE FISRT SECTOR OF THE FILE 
;2- LOAD THE WHOLE FILE AND COPY IT INTO RAM 
;3- EXCUTE THE FILE 
;THE ROOT DIR. AND FAT ARE LOCATED IN SOMEWHERE ON THE FLOPPY DRIVE AS FOLLOWS 

;1- SETTING UP AND LOADING THE ROOT DIR. 
MOV AH, 02H      ;THE FUNCTION CODE FOR LOADING ROOT DIR. 
MOV AL, 14      ;THE SIZE OF THE ROOT DIR. THE ROOT DIR. = 14 AND WE WANT TO LOAD IT ALL SO AL=14 
MOV BX, TEMP       ;THE TEMP STORAGE FOR THE DATA WILL BE READED OR LOADED 
MOV CH, 0      ;TRACK WE WANT TO LOAD, ITS TRACK 0 BEACUSE THE ROOT DIR. LOCATED THERE (CYLINDER) 
MOV CL, 2      ;SECTOR WE WANT TO LOAD, ITS SECTOR 2 BEACUSE THE ROOT DIR. LOCATED THERE 
MOV DH, 1      ;HEAD WE WANT TO LOAD, ITS HEAD 1 BEACUSE THE ROOT DIR. LOCATED THERE 
PUSHA       ;TO BE ABLE TO RETRY TO LOAD ROOT DIR. IF INT 13H FAILED 
LOAD_RD: 
INT 13H 
JNC LOAD_RD_DONE      ;IF WE ARRIVE HERE, THATS MEAN THAT THE ROOT DIR. LOADED SUCCESSFULLY 
CALL RESET_DRIVE      ;RESET FLOPPY FUNCTION CALL 
JMP LOAD_RD      ;RETRY IF INT 13H FAILED 


LOAD_RD_DONE: 
POPA 
;NOW WE WILL SEARCH IN THE ROOT DIR. TABLE IF IT CONTAINS THE DESIRED FILE NAME WHICH IS KERNEL.BIN 
;WE WILL USE CMPSB INSTRUCTION THAT COMPARES THE VALUE OF DS:SI AND ES:DI 
;ES AND DS ARE ALREADY SET 
;THE SEARCH WILL BE LIMITED TO SEARCH AMONG 11 BYTES BECAUSE THE FILE NAME IS 11 BYTES 

MOV DI, TEMP       ;THE RESULT WE GOT (THE ENTRY) 
MOV CX, 224      ;THE MAX. POSSIBLE FILE NUMBER THAT WE COULD HAVE IS 224 SO WE LIMIT THE SEARCH TO IT (THE VALUE THAT WILL BE DECREASED WHILE LOOPING) 

FIND_KERNEL: 
PUSH CX       ;PUSH CX AND DI BECAUSE THEY HELD IMPORTANT DATA THAT WE DONT WANT TO LOSE 
POP DX      
MOV SI, FILE_NAME      ;THE VALUE THAT WE WILL COMPARE THE RESULT OF ROOT DIR. TO FIND 
MOV CX, 11      ;TO REPEATE THE SEARCH PROCESS 11 TIMES(THE FILE NAME LENGTH) 
REP CMPSB      ;COPMARES SI WITH DI 

JE FOUND_KERNEL       ;IF WO GO TO THE NEXT LINE, THAT MEANS THAT THE KERNEL IS NOT FOUNDED YET 
;AND SINCE DI IS POINTS TO THE FIRST ENTRY, WE NEED TO MOVE TO THE NEXT ONE BY ADDING 32 

ADD AX, 32 
MOV DI, TEMP 
ADD DI, AX 
PUSH DX 
POP CX 

LOOP FIND_KERNEL 
;IF WE ARE HERE, THEN THE KERNEL IS NOT EXISTS 
;MOV SI, FAILED_TO_LOAD_KERNEL 
;CALL ECHO 
CLI 
INT 18H       ;CRASH AND HALT THE PROCESSOR 


FOUND_KERNEL:           ;IF WE FOUND THE KERNEL WE WILL BE HERE 
;NOW WE HAVE THE ENTRY POINT FOR THE KERNEL SAVED IN DL REGISTER 
;WE GOT THE KERNEL FROM THE FIRST 11 BYTES SO WE NEED TO ADD 15 TO GET TO THE 26 BYTES 
;THE FIRST SECTOR IS LOCATED AT 26 AND 27 SO WE MUST ADD 15 TO LOAD THE KERNEL IN THE FIRST SECTOR 
MOV AX, WORD [DI+15]       ;WORD ADDED TO COPY BOTH 26 AND 27 BYTES TO AX, THE WORD IS 2 BYTES 
MOV [ENTERY_POINT], AX 



;2- SETTING UP AND LOADING THE FAT 
MOV AX, 1 
MOV BX, TEMP       ;THE TEMP STORAGE FOR THE DATA WILL BE READED OR LOADED 
CALL LOG_TO_HTS 
MOV AH, 2      ;THE FUNCTION CODE FOR LOADING ROOT DIR. 
MOV AL, 9      ;THE SIZE OF THE ROOT DIR. THE ROOT DIR. = 14 AND WE WANT TO LOAD IT ALL SO AL=14 
PUSHA       ;TO BE ABLE TO RETRY TO LOAD ROOT DIR. IF INT 13H FAILED 
LOAD_FAT: 
INT 13H 
JNC LOAD_FAT_DONE      ;IF WE ARRIVE HERE, THATS MEAN THAT THE FAT LOADED SUCCESSFULLY 
CALL RESET_DRIVE      ;RESET FLOPPY FUNCTION CALL 
JMP LOAD_FAT       ;RETRY IF INT 13H FAILED 


LOAD_FAT_DONE:       ;IF LOADING FAT DONE SUCCESSFULLY, WE WILL BE HERE 
MOV AH, 2 
MOV AL, 1 
PUSH AX 

LOAD_SECTOR:       ;ROOT DIR. GIVES US A DATA SECTOR AND WE WANT A LOGICAL SECTOR, WE WILL DO IT HERE 
MOV AX, WORD [ENTERY_POINT] 
ADD AX, 31      ;31 ADDED TO DONE THE CONVERTION 

CALL LOG_TO_HTS       ;COVERTS THE LOGICAL SECTORS INTO HEAD TRACK SECTORS 
MOV AX, 2000H 
MOV ES, AX 
MOV BX, WORD[OFFSET_] 
POP AX 
PUSH AX 

INT 13H 
JNC GET_NEXT 
CALL RESET_DRIVE 
JMP LOAD_SECTOR 

GET_NEXT: 
MOV AX, [ENTERY_POINT] 
MOV DX, 0 
MOV BX, 6 
MUL BX 
MOV BX, 4 
DIV BX 
MOV SI, TEMP 
ADD SI, AX 
MOV AX, WORD[SI] 

OR DX, DX 
JZ EVEN 

ODD: 
SHR AX, 4 
JMP SHORT COMP_SECTOR 

EVEN: 
AND AX, 0FFFH 

COMP_SECTOR: 
MOV WORD [ENTERY_POINT], AX 
CMP AX, 0FF8H 
JAE END 
ADD WORD[OFFSET_], 512 
JMP LOAD_SECTOR 

END: 
;MOV SI, KERNEL_LOADED_MSG 
CALL ECHO 

CALL WAIT_FOR_KEY 

POP AX 
MOV DL, BYTE[BOOT_DEVICE] 
JMP 2000H:0000H 

OFFSET_     DW  0 
ALL_SECTORS    DW  18 
FACES     DW  2 
ENTERY_POINT     DW  0 
;FAILED_TO_LOAD_KERNEL     DB  "Error, Cannot Load The Kernel. Booting Process Aborted;",0 
BOOT_DEVICE        DB    0 
FILE_NAME    DB  "KERNEL BIN" 
;WELCOME_MSG        DB    "Litesoft bootloader Copyright (C) 2012-2016 By Mohamed El Sayed;",0 
;KERNEL_LOADED_MSG      DB    "Kernel Loaded, Press Any Key To Continue...",0 
TIMES 510 - ($-$$) DB  0    ;LOOK FOR EVERY SINGLE EMPTY BIT AND FILL IT WITH ZERO 
                 ;TILL THE BOOTLOADER SIZE BE 512 BYTE 
DW 0xAA55           ;THE BOOT SIGNETUARE, ALWAYS THE SAME 

TEMP:       ;HERE IN BYTE 513 WE HAVE SOME MEMORY THAT WILL NOT BE EXECUTED 
;AND WE CAN USE IT AS A TEMP MEMORY 

Метод я планируется использовать в создании образа дискеты, используя дд и написать свой загрузчик в первый сектор затем смонтировать его и скопировать мое ядро ​​к нему.

Команды я использовал

1- mkdosfs -C floppy.flp 1440, Эта команда создает образ дискеты

2- dd status=noxfer conv=notrunc if=boot.bin of=floppy.flp, Эта команда сжигает загрузчик в первый сектор

Эти команды работают очень будет и floppy с моим загрузчиком в первом секторе, успешно созданном

Проблема возникает, когда я пытаюсь смонтировать образ гибких дисков, чтобы скопировать ядро ​​на него с помощью followi нг команды

rm -rf tmp-loop

mkdir tmp-loop && mount -o loop -t vfat floppy.flp tmp-loop && cp kernel.bin tmp-loop/

Каждый раз, когда я пытаюсь монтировать образ дискеты я получаю эту ошибку

mount: wrong fs type, bad option, bad superblock on /dev/loop0, 
     missing codepage or helper program, or other error 

     In some cases useful info is found in syslog - try 
     dmesg | tail or so. 

Что такое решение для этой ошибки? Я использую Ubuntu 16.04

Если кто не знает ответа, но есть еще один способ создать bootabel образ дискеты вы можете оставить его в качестве ответа, любой метод, который получит эту работу будет полезно

Answer 1

Вам не хватает нужного BIOS Parameter Block(BPB) в начале вашего загрузчика. Эта структура содержит информацию, используемую/обновленную некоторыми BIOS; может быть использован загрузчиком для чтения файловой системы FAT на нераспределенном носителе, таком как дискета; должен присутствовать для программного обеспечения, такого как mount, для определения того, какой тип носителя представляет собой виртуальное изображение флоппи. В случае FAT12 на нераспределенном носителе (например, на дискете) информация о файловой системе присутствует в основной загрузочной записи BPB. Обычное расположение является DOS 3.4 EBPB, и это может выглядеть примерно так:

start: 
JMP MAIN 
TIMES 3-($-$$) DB 0x90 ; Support 2 or 3 byte encoded JMPs before BPB. 

; Dos 3.4 EBPB 1.44MB floppy 
OEMname:   db "mkfs.fat" ; mkfs.fat is what OEMname mkdosfs uses 
bytesPerSector: dw 512 
sectPerCluster: db 1 
reservedSectors: dw 1 
numFAT:   db 2 
numRootDirEntries: dw 224 
numSectors:  dw 2880 
mediaType:   db 0xf0 
numFATsectors:  dw 9 
sectorsPerTrack: dw 18 
numHeads:   dw 2 
numHiddenSectors: dd 0 
numSectorsHuge: dd 0 
driveNum:   db 0 
reserved:   db 0 
signature:   db 0x29 
volumeID:   dd 0x2d7e5a1a 
volumeLabel:  db "NO NAME " 
fileSysType:  db "FAT12 " 

основе DOS 3.4 EBPB выше и ваш boot.asm код, этой ВРВпредставляет один похожи на загрузочный диск 1.44 дискеты сектор производства с mkdosfs -C floppy.flp 1440:

bits 16 

section .text 
start: 
JMP MAIN 
TIMES 3-($-$$) DB 0x90 ; Support 2 or 3 byte encoded JMPs before BPB. 

; Dos 3.4 EBPB 1.44MB floppy 
OEMname:   db "mkfs.fat" ; mkfs.fat is what OEMname mkdosfs uses 
bytesPerSector: dw 512 
sectPerCluster: db 1 
reservedSectors: dw 1 
numFAT:   db 2 
numRootDirEntries: dw 224 
numSectors:  dw 2880 
mediaType:   db 0xf0 
numFATsectors:  dw 9 
sectorsPerTrack: dw 18 
numHeads:   dw 2 
numHiddenSectors: dd 0 
numSectorsHuge: dd 0 
driveNum:   db 0 
reserved:   db 0 
signature:   db 0x29 
volumeID:   dd 0x2d7e5a1a 
volumeLabel:  db "NO NAME " 
fileSysType:  db "FAT12 " 

WAIT_FOR_KEY: 
MOV AH, 00H 
INT 16H 
RET 

CLEAR: 
MOV AH, 0H      ;CHANGING THE VIDEO MODE TO CLEAR THE SCREEN 
MOV AL, 03H      ;VIDEO MODE COD 
INT 10H 
RET 

LOG_TO_HTS: 
PUSH BX 
PUSH AX 
MOV BX, AX 
MOV DX, 0 
DIV WORD[ALL_SECTORS] 
ADD DL, 01H 
MOV CL, DL 
MOV AX, BX 
MOV DX, 0 
DIV WORD [ALL_SECTORS] 
MOV DX, 0 
DIV WORD[FACES] 
MOV DH, DL 
MOV CH, AL 
POP AX 
POP BX 
MOV DL, BYTE [BOOT_DEVICE] 
RET 

ECHO:     ;-=-=-=PRINTING FUNCTION =-=-=-; 
LODSB     ;MOV ONE CHAR FROM SI TO AL AND DELETE IT FROM SI 
CMP AL, 0    ;CHECK IF THE VALUE IN AL=0, IF ITS ZERO THEN WE 
JE DONE     ;WE ARE DONE PRINTING, AND JUMP BACK TO THE MAIN FUNCTION 
CMP AL, 59 
JE NEWLINE 
MOV AH, 0EH    ;THE FUNCTION CODE FOR PRINTING (TELETYPE PRINTING) 
INT 10H     ;BIOS CALL 
JMP ECHO    ;IF WE ARRIVED TO THIS LINE THATS MEAN WE ARE NOT DONE WITH 
         ;PRINTING THE WHOLE STREING SO JUMP BACK AND COMPLETE THE PROCESS 

DONE:     ;LABEL CONTAINS ONE INSTRUCTION TO JUMP BACK TO THE LINE 
RET      ;WHERE WE CALLED THE ECHO FUNCTION 

NEWLINE: 
PUSHA 
MOV AH, 0EH 
MOV AL, 13 
INT 10H 
MOV AL, 10 
INT 10H 
POPA 
RET 

RESET_DRIVE:        ;RESET FLOPPY DRIVE FUNCTION 
MOV AX, 0       ;THE FUNCTION CODE TO RESET DRIVE 
MOV DL, BYTE [BOOT_DEVICE]       ;DRIVE ID TO RESET 
INT 13H 
RET 


MAIN:       ;THE MAIN FUNCTION LABEL 


;TO BEGIN LOADING EXTERNAL FILE LIKE KERNEL SOME THINGS MUST BE DONE LIKE : 
;1- SETTING UP THE STACK 
;2- SETTING UP THE SEGMENTS 
;3- SPECIFY THE BOOT DRIVE 

;SETTING UP THE STACK 
CLI        ;CLEAR INTERRUPTS TO SET THE SEGMENT 

XOR AX, AX      ;SET THE BOTTOM OF THE STACK 
MOV SS, AX 
MOV SP, 0XFFFF     ;SET THE TOP OF THE STACK 
STI        ;RESTORE THE INTERRUPTS 

;SETTING UP THE SEGMENTS 
MOV AX, 07C0H 
MOV DS, AX 
MOV ES, AX 
;AFTER SETTING UP SEGMENTS AND STACK, YOU ARE FREE TO CODE WHAT EVER YOU WANT 
;THE CPU WILL RECOGNISE YOUR CODE AS A BOOTLOADER 

CALL CLEAR 
;MOV SI, WELCOME_MSG 
;CALL ECHO 


MOV [BOOT_DEVICE], DL   ;SAVE THE DRIVE ID TO USE IT LATER 


;WE WILL USE IN 13H TO LOAD ROOT DIR. THAT WE NEED TO LOAD THE FIRST SECTOR OF THE KERNEL 
;THEN WE WILL LOAD FAT TO LOAD THE WHOLE KERNEL SINCE THE FILE LOAD PROCESS CONSISTS OF 3 STEPS 
;1- LOAD THE FISRT SECTOR OF THE FILE 
;2- LOAD THE WHOLE FILE AND COPY IT INTO RAM 
;3- EXCUTE THE FILE 
;THE ROOT DIR. AND FAT ARE LOCATED IN SOMEWHERE ON THE FLOPPY DRIVE AS FOLLOWS 

;1- SETTING UP AND LOADING THE ROOT DIR. 
MOV AH, 02H      ;THE FUNCTION CODE FOR LOADING ROOT DIR. 
MOV AL, 14      ;THE SIZE OF THE ROOT DIR. THE ROOT DIR. = 14 AND WE WANT TO LOAD IT ALL SO AL=14 
MOV BX, TEMP       ;THE TEMP STORAGE FOR THE DATA WILL BE READED OR LOADED 
MOV CH, 0      ;TRACK WE WANT TO LOAD, ITS TRACK 0 BEACUSE THE ROOT DIR. LOCATED THERE (CYLINDER) 
MOV CL, 2      ;SECTOR WE WANT TO LOAD, ITS SECTOR 2 BEACUSE THE ROOT DIR. LOCATED THERE 
MOV DH, 1      ;HEAD WE WANT TO LOAD, ITS HEAD 1 BEACUSE THE ROOT DIR. LOCATED THERE 
PUSHA       ;TO BE ABLE TO RETRY TO LOAD ROOT DIR. IF INT 13H FAILED 
LOAD_RD: 
INT 13H 
JNC LOAD_RD_DONE      ;IF WE ARRIVE HERE, THATS MEAN THAT THE ROOT DIR. LOADED SUCCESSFULLY 
CALL RESET_DRIVE      ;RESET FLOPPY FUNCTION CALL 
JMP LOAD_RD      ;RETRY IF INT 13H FAILED 


LOAD_RD_DONE: 
POPA 
;NOW WE WILL SEARCH IN THE ROOT DIR. TABLE IF IT CONTAINS THE DESIRED FILE NAME WHICH IS KERNEL.BIN 
;WE WILL USE CMPSB INSTRUCTION THAT COMPARES THE VALUE OF DS:SI AND ES:DI 
;ES AND DS ARE ALREADY SET 
;THE SEARCH WILL BE LIMITED TO SEARCH AMONG 11 BYTES BECAUSE THE FILE NAME IS 11 BYTES 

MOV DI, TEMP       ;THE RESULT WE GOT (THE ENTRY) 
MOV CX, 224      ;THE MAX. POSSIBLE FILE NUMBER THAT WE COULD HAVE IS 224 SO WE LIMIT THE SEARCH TO IT (THE VALUE THAT WILL BE DECREASED WHILE LOOPING) 

FIND_KERNEL: 
PUSH CX       ;PUSH CX AND DI BECAUSE THEY HELD IMPORTANT DATA THAT WE DONT WANT TO LOSE 
POP DX      
MOV SI, FILE_NAME      ;THE VALUE THAT WE WILL COMPARE THE RESULT OF ROOT DIR. TO FIND 
MOV CX, 11      ;TO REPEATE THE SEARCH PROCESS 11 TIMES(THE FILE NAME LENGTH) 
REP CMPSB      ;COPMARES SI WITH DI 

JE FOUND_KERNEL       ;IF WO GO TO THE NEXT LINE, THAT MEANS THAT THE KERNEL IS NOT FOUNDED YET 
;AND SINCE DI IS POINTS TO THE FIRST ENTRY, WE NEED TO MOVE TO THE NEXT ONE BY ADDING 32 

ADD AX, 32 
MOV DI, TEMP 
ADD DI, AX 
PUSH DX 
POP CX 

LOOP FIND_KERNEL 
;IF WE ARE HERE, THEN THE KERNEL IS NOT EXISTS 
;MOV SI, FAILED_TO_LOAD_KERNEL 
;CALL ECHO 
CLI 
INT 18H       ;CRASH AND HALT THE PROCESSOR 


FOUND_KERNEL:           ;IF WE FOUND THE KERNEL WE WILL BE HERE 
;NOW WE HAVE THE ENTRY POINT FOR THE KERNEL SAVED IN DL REGISTER 
;WE GOT THE KERNEL FROM THE FIRST 11 BYTES SO WE NEED TO ADD 15 TO GET TO THE 26 BYTES 
;THE FIRST SECTOR IS LOCATED AT 26 AND 27 SO WE MUST ADD 15 TO LOAD THE KERNEL IN THE FIRST SECTOR 
MOV AX, WORD [DI+15]       ;WORD ADDED TO COPY BOTH 26 AND 27 BYTES TO AX, THE WORD IS 2 BYTES 
MOV [ENTERY_POINT], AX 



;2- SETTING UP AND LOADING THE FAT 
MOV AX, 1 
MOV BX, TEMP       ;THE TEMP STORAGE FOR THE DATA WILL BE READED OR LOADED 
CALL LOG_TO_HTS 
MOV AH, 2      ;THE FUNCTION CODE FOR LOADING ROOT DIR. 
MOV AL, 9      ;THE SIZE OF THE ROOT DIR. THE ROOT DIR. = 14 AND WE WANT TO LOAD IT ALL SO AL=14 
PUSHA       ;TO BE ABLE TO RETRY TO LOAD ROOT DIR. IF INT 13H FAILED 
LOAD_FAT: 
INT 13H 
JNC LOAD_FAT_DONE      ;IF WE ARRIVE HERE, THATS MEAN THAT THE FAT LOADED SUCCESSFULLY 
CALL RESET_DRIVE      ;RESET FLOPPY FUNCTION CALL 
JMP LOAD_FAT       ;RETRY IF INT 13H FAILED 


LOAD_FAT_DONE:       ;IF LOADING FAT DONE SUCCESSFULLY, WE WILL BE HERE 
MOV AH, 2 
MOV AL, 1 
PUSH AX 

LOAD_SECTOR:       ;ROOT DIR. GIVES US A DATA SECTOR AND WE WANT A LOGICAL SECTOR, WE WILL DO IT HERE 
MOV AX, WORD [ENTERY_POINT] 
ADD AX, 31      ;31 ADDED TO DONE THE CONVERTION 

CALL LOG_TO_HTS       ;COVERTS THE LOGICAL SECTORS INTO HEAD TRACK SECTORS 
MOV AX, 2000H 
MOV ES, AX 
MOV BX, WORD[OFFSET_] 
POP AX 
PUSH AX 

INT 13H 
JNC GET_NEXT 
CALL RESET_DRIVE 
JMP LOAD_SECTOR 

GET_NEXT: 
MOV AX, [ENTERY_POINT] 
MOV DX, 0 
MOV BX, 6 
MUL BX 
MOV BX, 4 
DIV BX 
MOV SI, TEMP 
ADD SI, AX 
MOV AX, WORD[SI] 

OR DX, DX 
JZ EVEN 

ODD: 
SHR AX, 4 
JMP SHORT COMP_SECTOR 

EVEN: 
AND AX, 0FFFH 

COMP_SECTOR: 
MOV WORD [ENTERY_POINT], AX 
CMP AX, 0FF8H 
JAE END 
ADD WORD[OFFSET_], 512 
JMP LOAD_SECTOR 

END: 
;MOV SI, KERNEL_LOADED_MSG 
CALL ECHO 

CALL WAIT_FOR_KEY 

POP AX 
MOV DL, BYTE[BOOT_DEVICE] 
JMP 2000H:0000H 

OFFSET_     DW  0 
ALL_SECTORS    DW  18 
FACES     DW  2 
ENTERY_POINT     DW  0 
;FAILED_TO_LOAD_KERNEL     DB  "Error, Cannot Load The Kernel. Booting Process Aborted;",0 
BOOT_DEVICE        DB    0 
FILE_NAME    DB  "KERNEL BIN" 
;WELCOME_MSG        DB    "Litesoft bootloader Copyright (C) 2012-2016 By Mohamed El Sayed;",0 
;KERNEL_LOADED_MSG      DB    "Kernel Loaded, Press Any Key To Continue...",0 
TIMES 510 - ($-$$) DB  0    ;LOOK FOR EVERY SINGLE EMPTY BIT AND FILL IT WITH ZERO 
                 ;TILL THE BOOTLOADER SIZE BE 512 BYTE 
DW 0xAA55           ;THE BOOT SIGNETUARE, ALWAYS THE SAME 

TEMP:       ;HERE IN BYTE 513 WE HAVE SOME MEMORY THAT WILL NOT BE EXECUTED 
;AND WE CAN USE IT AS A TEMP MEMORY 

Если вы создаете boot.bin из этого кода и поместить его в образ дискеты и использовать команду кадрир заложить информацию о типе файла:

file floppy.flp 

Она должна производить что-то вроде этого, если он работал:

floppy.flp:, код смещения 0x99 + 3, OEM-ID «МКФС.жир», корень записи 224, сектора 2880 (объемы < = 32 MB), сектор/FAT 9, сектор/дорожки 18, серийный номер 0x2d7e5a1a, непомеченное, FAT (12 бит), а затем FAT

Если вы получить аналогичный выход он должен быть монтируемый с помощью команды mount.

---

Как вы могли заметить, данные в пределах EBPB/BPB можно использовать для навигации через файловую систему FAT12.