[pschweitzer] 70426: [BOOTSECT] fatx.S isn't for the FATX filesystem, it's just a generic naming, so pick up the next variable
26 Dec
2015
26 Dec
'15
5:44 p.m.
Author: pschweitzer
Date: Sat Dec 26 17:44:07 2015
New Revision: 70426
URL: http://svn.reactos.org/svn/reactos?rev=70426&view=rev
Log:
[BOOTSECT]
fatx.S isn't for the FATX filesystem, it's just a generic naming, so pick up the
next variable
Added:
trunk/reactos/boot/freeldr/bootsect/faty.S
- copied unchanged from r70425, trunk/reactos/boot/freeldr/bootsect/fatx.S
Removed:
trunk/reactos/boot/freeldr/bootsect/fatx.S
Modified:
trunk/reactos/boot/freeldr/bootsect/CMakeLists.txt
Modified: trunk/reactos/boot/freeldr/bootsect/CMakeLists.txt
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/bootsect/CMak…
==============================================================================
--- trunk/reactos/boot/freeldr/bootsect/CMakeLists.txt [iso-8859-1] (original)
+++ trunk/reactos/boot/freeldr/bootsect/CMakeLists.txt [iso-8859-1] Sat Dec 26 17:44:07
2015
@@ -7,15 +7,15 @@
CreateBootSectorTarget(fat ${CMAKE_CURRENT_SOURCE_DIR}/fat.S
${CMAKE_CURRENT_BINARY_DIR}/fat.bin 7c00)
CreateBootSectorTarget(fat32 ${CMAKE_CURRENT_SOURCE_DIR}/fat32.S
${CMAKE_CURRENT_BINARY_DIR}/fat32.bin 7c00)
- ## New versions using FATX.S (experimental)
+ ## New versions using FATY.S (experimental)
# add_definitions(-DFAT12)
- # CreateBootSectorTarget(fat_new ${CMAKE_CURRENT_SOURCE_DIR}/fatx.S
${CMAKE_CURRENT_BINARY_DIR}/fat_new.bin 7c00)
+ # CreateBootSectorTarget(fat_new ${CMAKE_CURRENT_SOURCE_DIR}/faty.S
${CMAKE_CURRENT_BINARY_DIR}/fat_new.bin 7c00)
# remove_definitions(-DFAT12)
# add_definitions(-DFAT16)
- # CreateBootSectorTarget(fat16_new ${CMAKE_CURRENT_SOURCE_DIR}/fatx.S
${CMAKE_CURRENT_BINARY_DIR}/fat16_new.bin 7c00)
+ # CreateBootSectorTarget(fat16_new ${CMAKE_CURRENT_SOURCE_DIR}/faty.S
${CMAKE_CURRENT_BINARY_DIR}/fat16_new.bin 7c00)
# remove_definitions(-DFAT16)
# add_definitions(-DFAT32)
- # CreateBootSectorTarget(fat32_new ${CMAKE_CURRENT_SOURCE_DIR}/fatx.S
${CMAKE_CURRENT_BINARY_DIR}/fat32_new.bin 7c00)
+ # CreateBootSectorTarget(fat32_new ${CMAKE_CURRENT_SOURCE_DIR}/faty.S
${CMAKE_CURRENT_BINARY_DIR}/fat32_new.bin 7c00)
# remove_definitions(-DFAT32)
CreateBootSectorTarget(isoboot ${CMAKE_CURRENT_SOURCE_DIR}/isoboot.S
${CMAKE_CURRENT_BINARY_DIR}/isoboot.bin 7000)
Removed: trunk/reactos/boot/freeldr/bootsect/fatx.S
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/bootsect/fatx…
==============================================================================
--- trunk/reactos/boot/freeldr/bootsect/fatx.S [iso-8859-1] (original)
+++ trunk/reactos/boot/freeldr/bootsect/fatx.S (removed)
@@ -1,589 +0,0 @@
-/*
- * COPYRIGHT: See COPYING in the top level directory
- * PROJECT: ReactOS Bootsector
- * FILE: boot/freeldr/bootsect/fatx.S
- * PURPOSE: Combined FAT16 and FAT32 boot sector
- * PROGRAMMERS: Brian Palmer
- * Timo Kreuzer
- */
-
-#define DISKREADBUFFER HEX(8E000)
-
-/*
- * Layout of a FAT volume:
- *
- * |---------------------------------------------------------
- * | * BootSector |
- * | * FS Information Sector (FAT32 only) | ReservedSectors
- * | * ... more reserved sectors ... |
- * |--------------------------------------------------------
- * | * FAT 1 | NumberOfFats
- * | * FAT 2 | *
- * | * [more FATs] | SectorsPerFat
- * |---------------------------------------------------------
- * | * Root Directory (FAT12/FAT16 only) | MaxRootEntries / 16
- * |---------------------------------------------------------
- * | * File data |
- * | .... |
- * |----------------------------------------
- */
-
-/* INCLUDES ******************************************************************/
-
-#include <asm.inc>
-#include <freeldr/include/arch/pc/x86common.h>
-
-#define ADDRESS_FOR_DIRENTRIES HEX(10000)
-
-SizeOfDataArea = 32
-
-/* Put the stack below the data area */
-BootSectorStackTop = (HEX(7c00) - SizeOfDataArea)
-
-/* Data area offsets for uninitialized data */
-DataAreaStart = BootSectorStackTop + 0 /* dword */
-#ifndef FAT32
-RootDirStartSector = BootSectorStackTop + 4 /* dword */
-#endif
-BiosCHSDriveSize = BootSectorStackTop + 8 /* dword */
-LBASectorsRead = BootSectorStackTop + 12 /* dword */
-ReadSectorsOffset = BootSectorStackTop + 16 /* word */
-ReadClusterOffset = BootSectorStackTop + 18 /* word */
-PutCharsOffset = BootSectorStackTop + 20 /* word */
-
-/* Macro for bp relative memory access to reduce code size */
-#define BP_REL(x) ss:[bp + x - BootSectorStackTop]
-
-/* The code starts at 0x7c00 */
-// org 7c00h
-
-.code16
-
-/******************************************************************************
- * BIOS Parameter Block (BPB) *
- ******************************************************************************/
-/* We have 3 bytes at the entry point to jump over the data area */
-start:
- jmp short main // FIXME: When compiling FAT32, assembler will complain
- // that the label is too far... Need investigation!
- nop
-
-/* Here starts the BIOS Parameter Block (BPB) data.
- The real data will be copied during install */
-OEMName:
- .ascii "FrLdr1.0"
-BytesPerSector:
- .word 512
-SectorsPerCluster:
- .byte 0
-ReservedSectors:
- .word 32
-NumberOfFats:
- .byte 2
-MaxRootEntries:
- .word 0 // Always zero for FAT32 volumes
-TotalSectors:
- .word 0 // Always zero for FAT32 volumes
-MediaDescriptor:
- .byte HEX(0f8)
-SectorsPerFat:
- .word 0 // Always zero for FAT32 volumes
-SectorsPerTrack:
- .word 0
-NumberOfHeads:
- .word 0
-HiddenSectors:
- .long 0
-TotalSectorsBig:
- .long 0
-
-/* Extra data for FAT32 volumes */
-#ifdef FAT32
-SectorsPerFatBig:
- .long 0
-ExtendedFlags:
- .word 0
-FSVersion:
- .word 0
-RootDirStartCluster:
- .long 0
-FSInfoSector:
- .word 0
-BackupBootSector:
- .word 6
-Reserved1:
- .byte 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
-#endif // FAT32
-
-BootDrive:
- .byte 0
-Reserved:
- .byte 0
-ExtendSig:
- .byte HEX(29)
-SerialNumber:
- .long 0
-VolumeLabel:
- .ascii "NO NAME "
-FileSystem:
- .ascii "FATxx "
-
-
-/******************************************************************************
- * String data *
- ******************************************************************************/
-
-filename:
- .ascii "FREELDR SYS"
-
-msgBootFailure:
- .ascii "Load failed!", CR, LF, NUL
-
-msgAnyKey:
- .ascii "Press any key to reboot...", NUL
-
-
-/******************************************************************************
- * Main code entry *
- * Input: DL = Boot drive *
- ******************************************************************************/
-main:
- /* First setup the segment registers */
- xor ax, ax
- mov ds, ax
- mov ss, ax
-
- /* Load the stack pointer */
- mov sp, BootSectorStackTop
-
- /* Load bp for relative memory access, which saves us some bytes of code
- size, when used with 32 bit instructions */
- mov bp, sp
-
- /* Load the boot drive from the BPB into al */
- mov al, byte ptr ds:[BootDrive]
-
- /* Check if it's valid */
- cmp al, HEX(0ff)
- je .SaveBootDrive
-
- /* Copy it into dl */
- mov dl, al
-
-.SaveBootDrive:
- /* Save the bootdrive in the BPB */
- mov byte ptr ds:[BootDrive], dl
-
-
-/******************************************************************************
- * Get drive parameters *
- ******************************************************************************/
-
- /* Call INT 13 to get the drive parameters:
- AH = 08h
- DL = drive (bit 7 set for hard disk)
- ES:DI = 0000h:0000h to guard against BIOS bugs */
- xor di, di
- mov ah, 8
- int HEX(13)
-
- /* Return from INT 13h/08h:
- CF set on error -> AH = status (07h)
- CF clear if successful -> AH = 00h
- AL = 00h on at least some BIOSes
- BL = drive type (AT/PS2 floppies only)
- CH = low eight bits of maximum cylinder number
- CL = bits 0:5 maximum sector number, bits 7:8 high two bits of maximum cylinder
number
- DH = maximum head number
- DL = number of drives
- ES:DI -> drive parameter table (floppies only) */
-
- /* Check for failure */
- jc BootFailure
-
-
-/******************************************************************************
- * Calculate drive size *
- ******************************************************************************/
-
- movzx ebx, ch // Put the low 8-bits of the cylinder count into EBX
- mov bh, cl // Put the high 2-bits in BH
- shr bh, 6 // Shift them into position, now BX contains the cylinder
count
-
- and cl, HEX(3f) // Mask off cylinder bits from sector count
- movzx ecx, cl // Move the sectors per track into ECX
-
- movzx eax, dh // Move the heads into EAX
-
- inc eax // Make it one based because the bios returns it zero based
- inc ebx // Make the cylinder count one based also
- mul ecx // Multiply heads with the sectors per track, result in
edx:eax
- mul ebx // Multiply the cylinders with (heads * sectors) [stored in
edx:eax already]
-
- // We now have the total number of sectors as reported
- // by the bios in eax, so store it in our variable
- mov dword ptr BP_REL(BiosCHSDriveSize), eax
-
-
-/******************************************************************************
- * Load the FAT *
- ******************************************************************************/
-
- /* Load the number of first sector of the FAT into eax */
- movzx eax, word ptr BP_REL(ReservedSectors)
- add eax, dword ptr BP_REL(HiddenSectors)
-
- /* Load sector count into ecx */
-#ifdef FAT32
- mov ecx, dword ptr BP_REL(SectorsPerFatBig)
-#else
- movzx ecx, word ptr BP_REL(SectorsPerFat)
-#endif
-
- /* Save FAT sector and size for later use */
- pushad
-
- /* Point ES:DI to the memory that is later the disk read buffer for freeldr.
- This way we cannot overwrite our FAT with freeldr data */
- mov bx, DISKREADBUFFER / 16
- mov es,bx
- xor di, di
-
- /* Read the sectors */
- call ReadSectors
-
- /* Restore FAT sector and size */
- popad
-
-
-/******************************************************************************
- * Get root directory / data area start *
- ******************************************************************************/
-
- /* Copy reserved + hidden sectors to EBX */
- mov ebx, eax
-
- /* Calculate (NumberOfFats * SectorsPerFat) */
- movzx eax, byte ptr BP_REL(NumberOfFats)
- mul ecx
-
- /* Add reserved sectors and hidden sectors */
- add eax, ebx
-
-#ifndef FAT32
- /* Save the starting sector of the root directory */
- mov dword ptr BP_REL(RootDirStartSector), eax
-
- /* Calculate number of sectors for the root dir:
- sectors = MaxRootEntries * 32 / 512 (rounded up!) */
- movzx ebx, word ptr BP_REL(MaxRootEntries)
- add ebx, 15
- shr ebx, 4
-
- /* Add the root dir start sector and save it as DataAreaStart */
- add ebx, eax
- mov dword ptr BP_REL(DataAreaStart), ebx
-#else
- mov dword ptr BP_REL(DataAreaStart), eax
-
- /* On FAT32 volumes the root dir start cluster is stored in the BPB */
- mov eax, dword ptr BP_REL(RootDirStartCluster)
-#endif
-
-
-/******************************************************************************
- * Search the root directory for freeldr *
- ******************************************************************************/
-.SearchForFreeldr:
-
- /* Load ES with the segment where we put the dir entries */
- mov bx, ADDRESS_FOR_DIRENTRIES / 16
- mov es, bx
-
- /* Set the address offset to 0 */
- xor di, di
-
-#ifdef FAT32
- /* Read the dir cluster. This loads the next cluster into EAX */
- call ReadCluster
-
- /* Calculate the numer of dir entries in this cluster:
- dx = SectorsPerCluster * 512 / 32 */
- movzx dx, byte ptr ds:[SectorsPerCluster]
- shl dx, 4
-#else
- /* Set the number of sectors to read to 1 */
- xor cx, cx
- inc cx
-
- /* Read the sector, but preserve ES */
- push es
- call ReadSectors
- pop es
-
- /* Set entry count to entries per sector */
- mov dx, (512 / 32)
-#endif
-
- /* Load the start offset of the dir entries into ebx */
- xor bx, bx
-
-.CheckDirEntry:
- /* Load the address of the name into di */
- mov di, bx
-
- /* If the first byte of the entry is 0 then we have reached the end */
- cmp byte ptr es:[di], ch
- jz BootFailure
-
- /* Compare with freeldr file name */
- mov si, offset filename
- mov cx, 11
- repe cmpsb
-
- /* Check if we found the file */
- jz .FoundFreeLoader
-
- /* File didn't match, go to next entry */
- add bx, 32
-
- /* Decrement entry count and check if we reached the end */
- dec dx
- jnz .CheckDirEntry
-
-#ifdef FAT32
- /* Check to see if this was the last cluster in the chain */
- cmp eax, HEX(0ffffff8)
- jnb BootFailure
-#endif
-
- /* Repeat the search process with the next sector / cluster.
- eax is already incremented in ReadSectors / ReadCluster */
- jmp .SearchForFreeldr
-
-
-/******************************************************************************
- * Load freeldr *
- ******************************************************************************/
-.FoundFreeLoader:
-
- /* Load the cluster number of freeldr into eax */
-#ifdef FAT32
-#error unsupported
-#else
- movzx eax, word ptr es:[bx + HEX(1A)]
-#endif
-
- /* Load es:di with the freeldr start address */
- mov dx, FREELDR_BASE / 16
- mov es, dx
- xor di, di
-
-.LoadNextCluster:
- /* Load the cluster to the current address. EAX is adjusted to the next
- cluster and ES is adjusted for the next read */
- call ReadCluster
-
- /* Check if this is the last cluster in the chain */
-#if defined(FAT32)
- cmp eax, HEX(0ffffff8)
-#elif defined(FAT12)
- cmp ax, HEX(0ff8)
-#else
- cmp ax, HEX(0fff8)
-#endif
- jb .LoadNextCluster
-
- /* Load boot drive into DL, boot partition into DH */
- mov dl, byte ptr ds:[BootDrive]
- mov dh, byte ptr ds:[BootPartition]
-
- /* Now the complete freeldr imag is loaded.
- Jump to the realmode entry point. */
- ljmp16 0, FREELDR_BASE
-
-
-
-BootFailure:
- mov si, offset msgBootFailure
- call PutChars
-
-
-Reboot:
- /* Output "Press any key to reboot" message */
- mov si, offset msgAnyKey
- call PutChars
-
- /* Wait for a keypress */
- xor ax, ax
- int HEX(16)
-
- /* Reboot */
- int HEX(19)
-
-
-/******************************************************************************
- * PROCEDURE ReadCluster *
- * Input: EAX = Cluster number, ES:DI = Target *
- * Modifies: EAX (next cluster number), BX, DX (undefined) *
- ******************************************************************************/
-ReadCluster:
-
- pushad
-
- // StartSector = ((Cluster - 2) * SectorsPerCluster) + SectorsForFat +
ReservedSectors + HiddenSectors
- // StartSector = ((Cluster - 2) * SectorsPerCluster) + DataAreaStart
-
- /* Substract 2 */
- dec eax
- dec eax
-
- /* Multiply with SectorsPerCluster */
- movzx ecx, byte ptr BP_REL(SectorsPerCluster)
- mul ecx
-
- /* Add DataAreaStart */
- add eax, dword ptr BP_REL(DataAreaStart)
-
- /* Call ReadSectors. EAX = SectorNumber, ECX = SectorsPerCluster */
- call ReadSectors
-
- /* Restore the cluster number */
- popad
-
- /* Save ES */
- push es
-
-#if defined(FAT32)
-#error FAT32 not implemented
-#elif defined(FAT12)
-#error FAT12 not implemented
-#else
- /* DX:AX = AX * 2 (since FAT16 entries are 2 bytes) */
- mov bx, 2
- mul bx
-
- /* Shift DX, so that it is the segment offset: DX = DX * (64K / 16) */
- shl dx, 12
-
- /* Put segment address of FAT into ES */
- add dx, DISKREADBUFFER / 16
- mov es, dx
-
- /* Put the FAT entry offset into EBX for indirect mov */
- mov bx, ax
-
- /* Put the content of the FAT entry into AX */
- mov ax, es:[bx]
-#endif
-
- /* Restore ES and return */
- pop es
- ret
-
-
-/******************************************************************************
- * PROCEDURE ReadSectors *
- * Input: EAX = Sector start number, ECX = number of sectors, ES:DI = Target *
- * Modifies: EAX (incremented by sector count), CX = 0, ES (incremented), *
- * EBX undefined *
- ******************************************************************************/
-ReadSectors:
- /* We could possibly also implement CHS, but it's currently unimplemented */
-//jmp $
-ReadSectorsLBA:
-
- /* Copy number of sectors to ebx */
- movzx ebx, cx
-
- /* Since the LBA calls only support 0x7F sectors at a time,
- we will limit ourselves to 64 */
- cmp bx, 64
- jbe .ReadSectorsLBA2
- mov bx, 64
-
-.ReadSectorsLBA2:
-
- /* Save logical sector number & sector count */
- pushad
-
- /* Setup the disk address packet on the stack */
- .byte HEX(66) // size overwrite prefix for next push
- push 0 // Put 64-bit logical block address (high part) on stack
- push eax // Put 64-bit logical block address (low part) on stack
- push es // Put transfer segment on stack
- push di // Put transfer offset on stack
- push bx // Set transfer count (for this round)
- push 16 // Set size of packet to 16
-
- /* Point si to the disk address packet on stack */
- mov si, sp
-
- /* Set the drive number */
- mov dl, byte ptr ds:[BootDrive]
-//jmp $
- /* Call INT 13h, AH = 42h - Extended Read
- Input: ...
- Modifies: ... */
- mov ah, HEX(42)
- int HEX(13)
-//jmp $
- /* Check for failure */
- jc BootFailure
-
- /* Remove disk address packet from stack */
- add sp, 16
-
- /* Adjust ES to point to the next sector */
- shl bx, 5
- mov ax, es
- add ax, bx
- mov es, ax
-
- /* Restore sector count & logical sector number */
- popad
-
- /* Adjust the sector number to the next sector we need to read
- by adding the number of sectors that we read */
- add eax, ebx
-
- /* Adjust remaining sectors */
- sub cx, bx
- jnz ReadSectorsLBA
-
- /* return */
- ret
-
-
-
-/******************************************************************************
- * PROCEDURE PutChars *
- * Input: ESI = Points to string to be printed *
- * Modifies: AL, AH, SI *
- ******************************************************************************/
-PutChars2:
- mov ah, HEX(0e)
- mov bx, 7
- int HEX(10)
-PutChars:
- lodsb
- or al, al
- jnz short PutChars2
- ret
-
-
-/******************************************************************************
- * Padding and boot sector signature *
- ******************************************************************************/
- /* Pad to 509 bytes */
- .org 509
-
-BootPartition:
- .byte 0
-
-BootSignature:
- .word HEX(0aa55) // BootSector signature
-
-.endcode16
-
-END
3190
days inactive
3190
days old
0 comments
1 participants
participants (1)
-
pschweitzer＠svn.reactos.org