Chameleon

Chameleon Commit Details

Date:2014-11-30 00:47:08 (9 years 3 months ago)
Author:ErmaC
Commit:2507
Parents: 2506
Message:Replace boot0 with boot0xg(1.0.3). Now boot0xg has all features of previous boot0 + recognize exFAT on MBR marked active + recognize exFAT+FAT32 on GPT typed as "Microsoft basic data". ( http://www.insanelymac.com/forum/topic/302938-exfat-volume-boot-recor d-for-chameleon )
Changes:
R/trunk/i386/boot0/boot0xg.s → /trunk/i386/boot0/boot0.old
M/trunk/i386/boot0/boot0.s
M/trunk/i386/libsaio/disk.c
M/trunk/CHANGES
M/trunk/i386/boot0/Makefile

File differences

trunk/i386/libsaio/disk.c
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case FDISK_DOS12:
case FDISK_DOS16B:
bvr = newGPTBVRef(biosdev, gptID, gptMap->ent_lba_start, gptMap,
MSDOSInitPartition,
MSDOSLoadFile,
MSDOSReadFile,
MSDOSGetDirEntry,
MSDOSGetFileBlock,
MSDOSGetUUID,
MSDOSGetDescription,
MSDOSFree,
0, kBIOSDevTypeHardDrive, 0);
MSDOSInitPartition,
MSDOSLoadFile,
MSDOSReadFile,
MSDOSGetDirEntry,
MSDOSGetFileBlock,
MSDOSGetUUID,
MSDOSGetDescription,
MSDOSFree,
0, kBIOSDevTypeHardDrive, 0);
break;
default:
trunk/i386/boot0/boot0xg.s
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; Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved.
;
; @APPLE_LICENSE_HEADER_START@
;
; Portions Copyright (c) 1999-2003 Apple Computer, Inc. All Rights
; Reserved. This file contains Original Code and/or Modifications of
; Original Code as defined in and that are subject to the Apple Public
; Source License Version 2.0 (the "License"). You may not use this file
; except in compliance with the License. Please obtain a copy of the
; License at http://www.apple.com/publicsource and read it before using
; this file.
;
; The Original Code and all software distributed under the License are
; distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
; EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
; INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
; FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT. Please see the
; License for the specific language governing rights and limitations
; under the License.
;
; @APPLE_LICENSE_HEADER_END@
;
; Boot Loader: boot0xg
;
; A small boot sector program written in x86 assembly whose only
; responsibility is to locate the active partition, load the
; partition booter into memory, and jump to the booter's entry point.
; It leaves the boot drive in DL and a pointer to the partition entry in SI.
;
; This boot loader must be placed in the Master Boot Record.
;
; In order to coexist with a fdisk partition table (64 bytes), and
; leave room for a two byte signature (0xAA55) in the end, boot0xg is
; restricted to 440 bytes (512 - 64 - 2 - 6). If boot0xg did not have to
; live in the MBR, then we would have 510 bytes to work with.
;
; boot0xg is always loaded by the BIOS or another booter to 0:7C00h.
;
; This code is written for the NASM assembler.
; nasm -f bin -DCONFIG_BOOT0_DEBUG=? -DCONFIG_BOOT0_VERBOSE=? boot0xg.s -o boot0xg
;
; This version of boot0xg implements hybrid GUID/MBR partition scheme support
;
;
; Turbo added EFI System Partition boot support
;
; Added KillerJK's switchPass2 modifications
;
;
; Set to 1 to enable obscure debug messages.
;
DEBUGEQU CONFIG_BOOT0_DEBUG
;
; Set to 1 to enable verbose mode
;
VERBOSEEQU CONFIG_BOOT0_VERBOSE
;
; Various constants.
;
kBoot0SegmentEQU 0x0000
kBoot0StackEQU 0xFFF0; boot0 stack pointer
kBoot0LoadAddrEQU 0x7C00; boot0 load address
kBoot0RelocAddrEQU 0xE000; boot0 relocated address
kMBRBufferEQU 0x1000; MBR buffer address
kLBA1BufferEQU 0x1200; LBA1 - GPT Partition Table Header buffer address
kGPTABufferEQU 0x1400; GUID Partition Entry Array buffer address
kPartTableOffsetEQU 0x1be
kMBRPartTableEQU kMBRBuffer + kPartTableOffset
kSectorBytesEQU 512; sector size in bytes
kBootSignatureEQU 0xAA55; boot sector signature
kHFSPSignatureEQU 'H+'; HFS+ volume signature
kHFSPCaseSignatureEQU 'HX'; HFS+ volume case-sensitive signature
kFAT32BootCodeOffset EQU 0x5a; offset of boot code in FAT32 boot sector
kBoot1FAT32MagicEQU 'BO'; Magic string to detect our boot1f32 code
kGPTSignatureLowEQU 'EFI '; GUID Partition Table Header Signature
kGPTSignatureHighEQU 'PART'
kGUIDLastDwordOffsEQU 12; last 4 byte offset of a GUID
kPartCountEQU 4; number of paritions per table
kPartTypeHFSEQU 0xaf; HFS+ Filesystem type
kPartTypeABHFSEQU 0xab; Apple_Boot partition
kPartTypePMBREQU 0xee; On all GUID Partition Table disks a Protective MBR (PMBR)
; in LBA 0 (that is, the first block) precedes the
; GUID Partition Table Header to maintain compatibility
; with existing tools that do not understand GPT partition structures.
; The Protective MBR has the same format as a legacy MBR
; and contains one partition entry with an OSType set to 0xEE
; reserving the entire space used on the disk by the GPT partitions,
; including all headers.
kPartActive EQU 0x80; active flag enabled
kPartInactive EQU 0x00; active flag disabled
kHFSGUID EQU 0x48465300; first 4 bytes of Apple HFS Partition Type GUID.
kAppleGUIDEQU 0xACEC4365; last 4 bytes of Apple type GUIDs.
kMicrosoftGUIDEQU 0xC79926B7; last 4 bytes of Microsoft Basic Data Partition Type GUID:
; EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
%ifdef FLOPPY
kDriveNumberEQU 0x00
%else
kDriveNumberEQU 0x80
%endif
;
; Format of fdisk partition entry.
;
; The symbol 'part_size' is automatically defined as an `EQU'
; giving the size of the structure.
;
struc part
.bootid resb 1 ; bootable or not
.head resb 1 ; starting head, sector, cylinder
.sect resb 1 ;
.cyl resb 1 ;
.type resb 1 ; partition type
.endhead resb 1 ; ending head, sector, cylinder
.endsect resb 1 ;
.endcyl resb 1 ;
.lba resd 1 ; starting lba
.sectors resd 1 ; size in sectors
endstruc
;
; Format of GPT Partition Table Header
;
strucgpth
.Signature resb8
.Revision resb4
.HeaderSizeresb4
.HeaderCRC32resb4
.Reservedresb4
.MyLBAresb8
.AlternateLBAresb8
.FirstUsableLBAresb8
.LastUsableLBAresb8
.DiskGUIDresb16
.PartitionEntryLBAresb8
.NumberOfPartitionEntriesresb4
.SizeOfPartitionEntryresb4
.PartitionEntryArrayCRC32resb4
endstruc
;
; Format of GUID Partition Entry Array
;
strucgpta
.PartitionTypeGUIDresb16
.UniquePartitionGUIDresb16
.StartingLBAresb8
.EndingLBAresb8
.Attributesresb8
.PartitionNameresb72
endstruc
;
; Macros.
;
%macro DebugCharMacro 1
mov al, %1
call print_char
%endmacro
%macro LogString 1
mov di, %1
call log_string
%endmacro
%if DEBUG
%define DebugChar(x) DebugCharMacro x
%else
%define DebugChar(x)
%endif
;--------------------------------------------------------------------------
; Start of text segment.
SEGMENT .text
ORG kBoot0RelocAddr
;--------------------------------------------------------------------------
; Boot code is loaded at 0:7C00h.
;
start:
;
; Set up the stack to grow down from kBoot0Segment:kBoot0Stack.
; Interrupts should be off while the stack is being manipulated.
;
cli ; interrupts off
xor ax, ax ; zero ax
mov ss, ax ; ss <- 0
mov sp, kBoot0Stack ; sp <- top of stack
sti ; reenable interrupts
mov es, ax ; es <- 0
mov ds, ax ; ds <- 0
;
; Relocate boot0 code.
;
mov si, kBoot0LoadAddr ; si <- source
mov di, kBoot0RelocAddr ; di <- destination
cld ; auto-increment SI and/or DI registers
mov cx, kSectorBytes/2 ; copy 256 words
repnz movsw ; repeat string move (word) operation
;
; Code relocated, jump to start_reloc in relocated location.
;
jmp kBoot0Segment:start_reloc
;--------------------------------------------------------------------------
; Start execution from the relocated location.
;
start_reloc:
DebugChar('>')
%if DEBUG
mov al, dl
call print_hex
%endif
;
; Since this code may not always reside in the MBR, always start by
; loading the MBR to kMBRBuffer and LBA1 to kGPTBuffer.
;
xor eax, eax
mov [my_lba], eax; store LBA sector 0 for read_lba function
mov al, 2; load two sectors: MBR and LBA1
mov bx, kMBRBuffer; MBR load address
call load
jc error; MBR load error
;
; Look for the booter partition in the MBR partition table,
; which is at offset kMBRPartTable.
;
mov si, kMBRPartTable; pointer to partition table
call find_boot; will not return on success
error:
LogString(boot_error_str)
hang:
hlt
jmp hang
;--------------------------------------------------------------------------
; Find the active (boot) partition and load the booter from the partition.
;
; Arguments:
; DL = drive number (0x80 + unit number)
; SI = pointer to fdisk partition table.
;
; Clobber list:
; EAX, BX, EBP
;
find_boot:
;
; Check for boot block signature 0xAA55 following the 4 partition
; entries.
;
cmp WORD [si + part_size * kPartCount], kBootSignature
jne .exit ; boot signature not found.
xor bx, bx; BL will be set to 1 later in case of
; Protective MBR has been found
inc bh; BH = 1. Giving a chance for a second pass
; to boot an inactive but boot1h aware HFS+ partition
; by scanning the MBR partition entries again.
.start_scan:
mov cx, kPartCount ; number of partition entries per table
.loop:
;
; First scan through the partition table looking for the active
; partition.
;
%if DEBUG
mov al, [si + part.type] ; print partition type
call print_hex
%endif
mov eax, [si + part.lba]; save starting LBA of current
mov [my_lba], eax; MBR partition entry for read_lba function
cmp BYTE [si + part.type], 0; unused partition?
je .continue ; skip to next entry
cmp BYTE [si + part.type], kPartTypePMBR; check for Protective MBR
jne .testPass
mov BYTE [si + part.bootid], kPartInactive; found Protective MBR
; clear active flag to make sure this protective
; partition won't be used as a bootable partition.
mov bl, 1; Assume we can deal with GPT but try to scan
; later if not found any other bootable partitions.
.testPass:
cmp bh, 1
jne .Pass2
.Pass1:
cmp BYTE [si + part.bootid], kPartActive; In pass 1 we are walking on the standard path
; by trying to hop on the active partition.
jne .continue
xor dh, dh ; Argument for loadBootSector to skip HFS+ partition
; signature check.
jmp .tryToBoot
.Pass2:
cmp BYTE [si + part.type], kPartTypeHFS; In pass 2 we're going to find a HFS+ partition
; equipped with boot1h in its boot record
; regardless if it's active or not.
jne .continue
mov dh, 1 ; Argument for loadBootSector to check HFS+ partition signature.
DebugChar('*')
;
; Found boot partition, read boot sector to memory.
;
.tryToBoot:
call loadBootSector
jne .continue
jmp SHORT initBootLoader
.continue:
add si, BYTE part_size ; advance SI to next partition entry
loop .loop ; loop through all partition entries
;
; Scanned all partitions but not found any with active flag enabled
; Anyway if we found a protective MBR before we still have a chance
; for a possible GPT Header at LBA 1
;
dec bl
jnz .switchPass2; didn't find Protective MBR before
call checkGPT
.switchPass2:
;
; Switching to Pass 2
; try to find a boot1h aware HFS+ MBR partition
;
dec bh
mov si, kMBRPartTable; set SI to first entry of MBR Partition table
jz .start_scan; scan again
.exit:
ret; Giving up.
;
; Jump to partition booter. The drive number is already in register DL.
; SI is pointing to the modified partition entry.
;
initBootLoader:
DebugChar('J')
%if VERBOSE
LogString(done_str)
%endif
jmp kBoot0LoadAddr
;
; Found Protective MBR Partition Type: 0xEE
; Check for 'EFI PART' string at the beginning
; of LBA1 for possible GPT Table Header
;
checkGPT:
push bx
mov di, kLBA1Buffer; address of GUID Partition Table Header
cmp DWORD [di], kGPTSignatureLow; looking for 'EFI '
jne .exit; not found. Giving up.
cmp DWORD [di + 4], kGPTSignatureHigh ; looking for 'PART'
jne .exit; not found. Giving up indeed.
mov si, di
;
; Loading GUID Partition Table Array
;
mov eax, [si + gpth.PartitionEntryLBA] ; starting LBA of GPT Array
mov [my_lba], eax; save starting LBA for read_lba function
mov cx, [si + gpth.NumberOfPartitionEntries]; number of GUID Partition Array entries
mov bx, [si + gpth.SizeOfPartitionEntry]; size of GUID Partition Array entry
push bx; push size of GUID Partition entry
;
; Calculating number of sectors we need to read for loading a GPT Array
;
; push dx; preserve DX (DL = BIOS drive unit number)
; mov ax, cx; AX * BX = number of entries * size of one entry
; mul bx; AX = total byte size of GPT Array
; pop dx; restore DX
; shr ax, 9; convert to sectors
;
; ... or:
; Current GPT Arrays uses 128 partition entries each 128 bytes long
; 128 entries * 128 bytes long GPT Array entries / 512 bytes per sector = 32 sectors
;
moval, 32; maximum sector size of GPT Array (hardcoded method)
mov bx, kGPTABuffer
push bx; push address of GPT Array
call load; read GPT Array
pop si; SI = address of GPT Array
pop bx; BX = size of GUID Partition Array entry
jc error
;
; Walk through GUID Partition Table Array
; and load boot record from first available HFS+ partition.
;
; If it has boot signature (0xAA55) then jump to it
; otherwise skip to next partition.
;
%if VERBOSE
LogString(gpt_str)
%endif
.gpt_loop:
mov eax, [si + gpta.PartitionTypeGUID + kGUIDLastDwordOffs]
cmpeax, kAppleGUID; check current GUID Partition for Apple's GUID type
je.gpt_ok
;
; Turbo - also try EFI System Partition
;
cmpeax, kMicrosoftGUID; check current GUID Partition for Microsoft Basic Data Partition GUID type
jne.gpt_continue
.gpt_ok:
;
; Found HFS Partition
;
mov eax, [si + gpta.StartingLBA]; load boot sector from StartingLBA
mov [my_lba], eax
mov dh, 1; Argument for loadBootSector to check HFS+ partition signature.
call loadBootSector
jne .gpt_continue; no boot loader signature
mov si, kMBRPartTable; fake the current GUID Partition
mov [si + part.lba], eax; as MBR style partition for boot1h
mov BYTE [si + part.type], kPartTypeHFS; with HFS+ filesystem type (0xAF)
jmp SHORT initBootLoader
.gpt_continue:
add si, bx; advance SI to next partition entry
loop .gpt_loop; loop through all partition entries
.exit:
pop bx
ret; no more GUID partitions. Giving up.
;--------------------------------------------------------------------------
; loadBootSector - Load boot sector
;
; Arguments:
; DL = drive number (0x80 + unit number)
; DH = 0 skip HFS+ partition signature checking
; 1 enable HFS+ partition signature checking
; [my_lba] = starting LBA.
;
; Returns:
; ZF = 0 if boot sector hasn't kBootSignature
; 1 if boot sector has kBootSignature
;
loadBootSector:
pusha
mov al, 3
mov bx, kBoot0LoadAddr
call load
jc error
ordh, dh
jz.checkBootSignature
.checkHFSSignature:
%if 0
%if VERBOSE
LogString(test_str)
%endif
%endif
;
; Looking for HFSPlus ('H+') or HFSPlus case-sensitive ('HX') signature.
;
movax, [kBoot0LoadAddr + 2 * kSectorBytes]
cmp ax, kHFSPSignature; 'H+'
je.checkBootSignature
cmpax, kHFSPCaseSignature; 'HX'
je.checkBootSignature
;
; Looking for exFAT signature
;
movax, [kBoot0LoadAddr + 3]
cmpax, 0x5845; 'EX'
jz.checkBootSignature
;
; Looking for boot1f32 magic string.
;
movax, [kBoot0LoadAddr + kFAT32BootCodeOffset]
cmpax, kBoot1FAT32Magic
jne .exit
.checkBootSignature:
;
; Check for boot block signature 0xAA55
;
mov di, bx
cmp WORD [di + kSectorBytes - 2], kBootSignature
.exit:
popa
ret
;--------------------------------------------------------------------------
; load - Load one or more sectors from a partition.
;
; Arguments:
; AL = number of 512-byte sectors to read.
; ES:BX = pointer to where the sectors should be stored.
; DL = drive number (0x80 + unit number)
; [my_lba] = starting LBA.
;
; Returns:
; CF = 0 success
; 1 error
;
load:
push cx
.ebios:
mov cx, 5 ; load retry count
.ebios_loop:
call read_lba ; use INT13/F42
jnc .exit
loop .ebios_loop
.exit:
pop cx
ret
;--------------------------------------------------------------------------
; read_lba - Read sectors from a partition using LBA addressing.
;
; Arguments:
; AL = number of 512-byte sectors to read (valid from 1-127).
; ES:BX = pointer to where the sectors should be stored.
; DL = drive number (0x80 + unit number)
; [my_lba] = starting LBA.
;
; Returns:
; CF = 0 success
; 1 error
;
read_lba:
pushad ; save all registers
mov bp, sp ; save current SP
;
; Create the Disk Address Packet structure for the
; INT13/F42 (Extended Read Sectors) on the stack.
;
; push DWORD 0 ; offset 12, upper 32-bit LBA
push ds ; For sake of saving memory,
push ds ; push DS register, which is 0.
mov ecx, [my_lba] ; offset 8, lower 32-bit LBA
push ecx
push es ; offset 6, memory segment
push bx ; offset 4, memory offset
xor ah, ah ; offset 3, must be 0
push ax ; offset 2, number of sectors
; It pushes 2 bytes with a smaller opcode than if WORD was used
push BYTE 16 ; offset 0-1, packet size
DebugChar('<')
%if DEBUG
mov eax, ecx
call print_hex
%endif
;
; INT13 Func 42 - Extended Read Sectors
;
; Arguments:
; AH = 0x42
; DL = drive number (80h + drive unit)
; DS:SI = pointer to Disk Address Packet
;
; Returns:
; AH = return status (success is 0)
; carry = 0 success
; 1 error
;
; Packet offset 2 indicates the number of sectors read
; successfully.
;
mov si, sp
mov ah, 0x42
int 0x13
jnc .exit
DebugChar('R') ; indicate INT13/F42 error
;
; Issue a disk reset on error.
; Should this be changed to Func 0xD to skip the diskette controller
; reset?
;
xor ax, ax ; Func 0
int 0x13 ; INT 13
stc ; set carry to indicate error
.exit:
mov sp, bp ; restore SP
popad
ret
;--------------------------------------------------------------------------
; Write a string with 'boot0: ' prefix to the console.
;
; Arguments:
; ES:DI pointer to a NULL terminated string.
;
; Clobber list:
; DI
;
log_string:
pusha
pushdi
movsi, log_title_str
callprint_string
popsi
callprint_string
popa
ret
;--------------------------------------------------------------------------
; Write a string to the console.
;
; Arguments:
; DS:SI pointer to a NULL terminated string.
;
; Clobber list:
; AX, BX, SI
;
print_string:
mov bx, 1 ; BH=0, BL=1 (blue)
cld ; increment SI after each lodsb call
.loop:
lodsb ; load a byte from DS:SI into AL
cmp al, 0 ; Is it a NULL?
je .exit ; yes, all done
mov ah, 0xE ; INT10 Func 0xE
int 0x10 ; display byte in tty mode
jmp short .loop
.exit:
ret
%if DEBUG
;--------------------------------------------------------------------------
; Write a ASCII character to the console.
;
; Arguments:
; AL = ASCII character.
;
print_char:
pusha
mov bx, 1 ; BH=0, BL=1 (blue)
mov ah, 0x0e ; bios INT 10, Function 0xE
int 0x10 ; display byte in tty mode
popa
ret
;--------------------------------------------------------------------------
; Write the 4-byte value to the console in hex.
;
; Arguments:
; EAX = Value to be displayed in hex.
;
print_hex:
pushad
mov cx, WORD 4
bswap eax
.loop:
push ax
ror al, 4
call print_nibble ; display upper nibble
pop ax
call print_nibble ; display lower nibble
ror eax, 8
loop .loop
mov al, 10 ; carriage return
call print_char
mov al, 13
call print_char
popad
ret
print_nibble:
and al, 0x0f
add al, '0'
cmp al, '9'
jna .print_ascii
add al, 'A' - '9' - 1
.print_ascii:
call print_char
ret
getc:
pusha
mov ah, 0
int 0x16
popa
ret
%endif ;DEBUG
;--------------------------------------------------------------------------
; NULL terminated strings.
;
log_title_strdb 10, 13, 'boot0: ', 0
%if VERBOSE
gpt_strdb 'GPT', 0
%if 0
test_strdb 'test', 0
%endif
done_strdb 'done', 0
%endif
boot_error_str db 'error', 0
;--------------------------------------------------------------------------
; Pad the rest of the 512 byte sized booter with zeroes. The last
; two bytes is the mandatory boot sector signature.
;
; If the booter code becomes too large, then nasm will complain
; that the 'times' argument is negative.
;
; According to EFI specification, maximum boot code size is 440 bytes
;
;
; XXX - compilation errors with debug enabled (see comment above about nasm)
; Azi: boot0.s:808: error: TIMES value -111 is negative
; boot0.s:811: error: TIMES value -41 is negative
;
pad_boot:
times 440-($-$$) db 0
pad_table_and_sig:
times 510-($-$$) db 0
dw kBootSignature
ABSOLUTE 0xE400
;
; In memory variables.
;
my_lbaresd1; Starting LBA for read_lba function
; END
trunk/i386/boot0/boot0.old
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; Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved.
;
; @APPLE_LICENSE_HEADER_START@
;
; Portions Copyright (c) 1999-2003 Apple Computer, Inc. All Rights
; Reserved. This file contains Original Code and/or Modifications of
; Original Code as defined in and that are subject to the Apple Public
; Source License Version 2.0 (the "License"). You may not use this file
; except in compliance with the License. Please obtain a copy of the
; License at http://www.apple.com/publicsource and read it before using
; this file.
;
; The Original Code and all software distributed under the License are
; distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
; EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
; INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
; FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT. Please see the
; License for the specific language governing rights and limitations
; under the License.
;
; @APPLE_LICENSE_HEADER_END@
;
; Boot Loader: boot0
;
; A small boot sector program written in x86 assembly whose only
; responsibility is to locate the active partition, load the
; partition booter into memory, and jump to the booter's entry point.
; It leaves the boot drive in DL and a pointer to the partition entry in SI.
;
; This boot loader must be placed in the Master Boot Record.
;
; In order to coexist with a fdisk partition table (64 bytes), and
; leave room for a two byte signature (0xAA55) in the end, boot0 is
; restricted to 446 bytes (512 - 64 - 2). If boot0 did not have to
; live in the MBR, then we would have 510 bytes to work with.
;
; boot0 is always loaded by the BIOS or another booter to 0:7C00h.
;
; This code is written for the NASM assembler.
; nasm boot0.s -o boot0
;
; This version of boot0 implements hybrid GUID/MBR partition scheme support
;
;
; Turbo added EFI System Partition boot support
;
; Added KillerJK's switchPass2 modifications
;
;
; Set to 1 to enable obscure debug messages.
;
DEBUGEQU CONFIG_BOOT0_DEBUG
;
; Set to 1 to enable verbose mode
;
VERBOSEEQU CONFIG_BOOT0_VERBOSE
;
; Various constants.
;
kBoot0SegmentEQU 0x0000
kBoot0StackEQU 0xFFF0; boot0 stack pointer
kBoot0LoadAddrEQU 0x7C00; boot0 load address
kBoot0RelocAddrEQU 0xE000; boot0 relocated address
kMBRBufferEQU 0x1000; MBR buffer address
kLBA1BufferEQU 0x1200; LBA1 - GPT Partition Table Header buffer address
kGPTABufferEQU 0x1400; GUID Partition Entry Array buffer address
kPartTableOffsetEQU 0x1be
kMBRPartTableEQU kMBRBuffer + kPartTableOffset
kSectorBytesEQU 512; sector size in bytes
kBootSignatureEQU 0xAA55; boot sector signature
kHFSPSignatureEQU 'H+'; HFS+ volume signature
kHFSPCaseSignatureEQU 'HX'; HFS+ volume case-sensitive signature
kFAT32BootCodeOffset EQU 0x5a; offset of boot code in FAT32 boot sector
kBoot1FAT32MagicEQU 'BO'; Magic string to detect our boot1f32 code
kGPTSignatureLowEQU 'EFI '; GUID Partition Table Header Signature
kGPTSignatureHighEQU 'PART'
kGUIDLastDwordOffsEQU 12; last 4 byte offset of a GUID
kPartCountEQU 4; number of paritions per table
kPartTypeHFSEQU 0xaf; HFS+ Filesystem type
kPartTypeABHFSEQU 0xab; Apple_Boot partition
kPartTypePMBREQU 0xee; On all GUID Partition Table disks a Protective MBR (PMBR)
; in LBA 0 (that is, the first block) precedes the
; GUID Partition Table Header to maintain compatibility
; with existing tools that do not understand GPT partition structures.
; The Protective MBR has the same format as a legacy MBR
; and contains one partition entry with an OSType set to 0xEE
; reserving the entire space used on the disk by the GPT partitions,
; including all headers.
kPartActive EQU 0x80; active flag enabled
kPartInactive EQU 0x00; active flag disabled
kHFSGUID EQU 0x48465300; first 4 bytes of Apple HFS Partition Type GUID.
kAppleGUIDEQU 0xACEC4365; last 4 bytes of Apple type GUIDs.
kEFISystemGUIDEQU 0x3BC93EC9; last 4 bytes of EFI System Partition Type GUID:
; C12A7328-F81F-11D2-BA4B-00A0C93EC93B
%ifdef FLOPPY
kDriveNumberEQU 0x00
%else
kDriveNumberEQU 0x80
%endif
;
; Format of fdisk partition entry.
;
; The symbol 'part_size' is automatically defined as an `EQU'
; giving the size of the structure.
;
struc part
.bootid resb 1 ; bootable or not
.head resb 1 ; starting head, sector, cylinder
.sect resb 1 ;
.cyl resb 1 ;
.type resb 1 ; partition type
.endhead resb 1 ; ending head, sector, cylinder
.endsect resb 1 ;
.endcyl resb 1 ;
.lba resd 1 ; starting lba
.sectors resd 1 ; size in sectors
endstruc
;
; Format of GPT Partition Table Header
;
strucgpth
.Signature resb8
.Revision resb4
.HeaderSizeresb4
.HeaderCRC32resb4
.Reservedresb4
.MyLBAresb8
.AlternateLBAresb8
.FirstUsableLBAresb8
.LastUsableLBAresb8
.DiskGUIDresb16
.PartitionEntryLBAresb8
.NumberOfPartitionEntriesresb4
.SizeOfPartitionEntryresb4
.PartitionEntryArrayCRC32resb4
endstruc
;
; Format of GUID Partition Entry Array
;
strucgpta
.PartitionTypeGUIDresb16
.UniquePartitionGUIDresb16
.StartingLBAresb8
.EndingLBAresb8
.Attributesresb8
.PartitionNameresb72
endstruc
;
; Macros.
;
%macro DebugCharMacro 1
mov al, %1
call print_char
%endmacro
%macro LogString 1
mov di, %1
call log_string
%endmacro
%if DEBUG
%define DebugChar(x) DebugCharMacro x
%else
%define DebugChar(x)
%endif
;--------------------------------------------------------------------------
; Start of text segment.
SEGMENT .text
ORG kBoot0RelocAddr
;--------------------------------------------------------------------------
; Boot code is loaded at 0:7C00h.
;
start:
;
; Set up the stack to grow down from kBoot0Segment:kBoot0Stack.
; Interrupts should be off while the stack is being manipulated.
;
cli ; interrupts off
xor ax, ax ; zero ax
mov ss, ax ; ss <- 0
mov sp, kBoot0Stack ; sp <- top of stack
sti ; reenable interrupts
mov es, ax ; es <- 0
mov ds, ax ; ds <- 0
;
; Relocate boot0 code.
;
mov si, kBoot0LoadAddr ; si <- source
mov di, kBoot0RelocAddr ; di <- destination
cld ; auto-increment SI and/or DI registers
mov cx, kSectorBytes/2 ; copy 256 words
repnz movsw ; repeat string move (word) operation
;
; Code relocated, jump to start_reloc in relocated location.
;
jmp kBoot0Segment:start_reloc
;--------------------------------------------------------------------------
; Start execution from the relocated location.
;
start_reloc:
DebugChar('>')
%if DEBUG
mov al, dl
call print_hex
%endif
;
; Since this code may not always reside in the MBR, always start by
; loading the MBR to kMBRBuffer and LBA1 to kGPTBuffer.
;
xor eax, eax
mov [my_lba], eax; store LBA sector 0 for read_lba function
mov al, 2; load two sectors: MBR and LBA1
mov bx, kMBRBuffer; MBR load address
call load
jc error; MBR load error
;
; Look for the booter partition in the MBR partition table,
; which is at offset kMBRPartTable.
;
mov si, kMBRPartTable; pointer to partition table
call find_boot; will not return on success
error:
LogString(boot_error_str)
hang:
hlt
jmp hang
;--------------------------------------------------------------------------
; Find the active (boot) partition and load the booter from the partition.
;
; Arguments:
; DL = drive number (0x80 + unit number)
; SI = pointer to fdisk partition table.
;
; Clobber list:
; EAX, BX, EBP
;
find_boot:
;
; Check for boot block signature 0xAA55 following the 4 partition
; entries.
;
cmp WORD [si + part_size * kPartCount], kBootSignature
jne .exit ; boot signature not found.
xor bx, bx; BL will be set to 1 later in case of
; Protective MBR has been found
inc bh; BH = 1. Giving a chance for a second pass
; to boot an inactive but boot1h aware HFS+ partition
; by scanning the MBR partition entries again.
.start_scan:
mov cx, kPartCount ; number of partition entries per table
.loop:
;
; First scan through the partition table looking for the active
; partition.
;
%if DEBUG
mov al, [si + part.type] ; print partition type
call print_hex
%endif
mov eax, [si + part.lba]; save starting LBA of current
mov [my_lba], eax; MBR partition entry for read_lba function
cmp BYTE [si + part.type], 0; unused partition?
je .continue ; skip to next entry
cmp BYTE [si + part.type], kPartTypePMBR; check for Protective MBR
jne .testPass
mov BYTE [si + part.bootid], kPartInactive; found Protective MBR
; clear active flag to make sure this protective
; partition won't be used as a bootable partition.
mov bl, 1; Assume we can deal with GPT but try to scan
; later if not found any other bootable partitions.
.testPass:
cmp bh, 1
jne .Pass2
.Pass1:
cmp BYTE [si + part.bootid], kPartActive; In pass 1 we are walking on the standard path
; by trying to hop on the active partition.
jne .continue
xor dh, dh ; Argument for loadBootSector to skip HFS+ partition
; signature check.
jmp .tryToBoot
.Pass2:
cmp BYTE [si + part.type], kPartTypeHFS; In pass 2 we're going to find a HFS+ partition
; equipped with boot1h in its boot record
; regardless if it's active or not.
jne .continue
mov dh, 1 ; Argument for loadBootSector to check HFS+ partition signature.
DebugChar('*')
;
; Found boot partition, read boot sector to memory.
;
.tryToBoot:
call loadBootSector
jne .continue
jmp SHORT initBootLoader
.continue:
add si, BYTE part_size ; advance SI to next partition entry
loop .loop ; loop through all partition entries
;
; Scanned all partitions but not found any with active flag enabled
; Anyway if we found a protective MBR before we still have a chance
; for a possible GPT Header at LBA 1
;
dec bl
jnz .switchPass2; didn't find Protective MBR before
call checkGPT
.switchPass2:
;
; Switching to Pass 2
; try to find a boot1h aware HFS+ MBR partition
;
dec bh
mov si, kMBRPartTable; set SI to first entry of MBR Partition table
jz .start_scan; scan again
.exit:
ret; Giving up.
;
; Jump to partition booter. The drive number is already in register DL.
; SI is pointing to the modified partition entry.
;
initBootLoader:
DebugChar('J')
%if VERBOSE
LogString(done_str)
%endif
jmp kBoot0LoadAddr
;
; Found Protective MBR Partition Type: 0xEE
; Check for 'EFI PART' string at the beginning
; of LBA1 for possible GPT Table Header
;
checkGPT:
push bx
mov di, kLBA1Buffer; address of GUID Partition Table Header
cmp DWORD [di], kGPTSignatureLow; looking for 'EFI '
jne .exit; not found. Giving up.
cmp DWORD [di + 4], kGPTSignatureHigh ; looking for 'PART'
jne .exit; not found. Giving up indeed.
mov si, di
;
; Loading GUID Partition Table Array
;
mov eax, [si + gpth.PartitionEntryLBA] ; starting LBA of GPT Array
mov [my_lba], eax; save starting LBA for read_lba function
mov cx, [si + gpth.NumberOfPartitionEntries]; number of GUID Partition Array entries
mov bx, [si + gpth.SizeOfPartitionEntry]; size of GUID Partition Array entry
push bx; push size of GUID Partition entry
;
; Calculating number of sectors we need to read for loading a GPT Array
;
; push dx; preserve DX (DL = BIOS drive unit number)
; mov ax, cx; AX * BX = number of entries * size of one entry
; mul bx; AX = total byte size of GPT Array
; pop dx; restore DX
; shr ax, 9; convert to sectors
;
; ... or:
; Current GPT Arrays uses 128 partition entries each 128 bytes long
; 128 entries * 128 bytes long GPT Array entries / 512 bytes per sector = 32 sectors
;
moval, 32; maximum sector size of GPT Array (hardcoded method)
mov bx, kGPTABuffer
push bx; push address of GPT Array
call load; read GPT Array
pop si; SI = address of GPT Array
pop bx; BX = size of GUID Partition Array entry
jc error
;
; Walk through GUID Partition Table Array
; and load boot record from first available HFS+ partition.
;
; If it has boot signature (0xAA55) then jump to it
; otherwise skip to next partition.
;
%if VERBOSE
LogString(gpt_str)
%endif
.gpt_loop:
mov eax, [si + gpta.PartitionTypeGUID + kGUIDLastDwordOffs]
cmpeax, kAppleGUID; check current GUID Partition for Apple's GUID type
je.gpt_ok
;
; Turbo - also try EFI System Partition
;
cmpeax, kEFISystemGUID; check current GUID Partition for EFI System Partition GUID type
jne.gpt_continue
.gpt_ok:
;
; Found HFS Partition
;
mov eax, [si + gpta.StartingLBA]; load boot sector from StartingLBA
mov [my_lba], eax
mov dh, 1; Argument for loadBootSector to check HFS+ partition signature.
call loadBootSector
jne .gpt_continue; no boot loader signature
mov si, kMBRPartTable; fake the current GUID Partition
mov [si + part.lba], eax; as MBR style partition for boot1h
mov BYTE [si + part.type], kPartTypeHFS; with HFS+ filesystem type (0xAF)
jmp SHORT initBootLoader
.gpt_continue:
add si, bx; advance SI to next partition entry
loop .gpt_loop; loop through all partition entries
.exit:
pop bx
ret; no more GUID partitions. Giving up.
;--------------------------------------------------------------------------
; loadBootSector - Load boot sector
;
; Arguments:
; DL = drive number (0x80 + unit number)
; DH = 0 skip HFS+ partition signature checking
; 1 enable HFS+ partition signature checking
; [my_lba] = starting LBA.
;
; Returns:
; ZF = 0 if boot sector hasn't kBootSignature
; 1 if boot sector has kBootSignature
;
loadBootSector:
pusha
mov al, 3
mov bx, kBoot0LoadAddr
call load
jc error
ordh, dh
jz.checkBootSignature
.checkHFSSignature:
%if VERBOSE
LogString(test_str)
%endif
;
; Looking for HFSPlus ('H+') or HFSPlus case-sensitive ('HX') signature.
;
movax, [kBoot0LoadAddr + 2 * kSectorBytes]
cmp ax, kHFSPSignature; 'H+'
je.checkBootSignature
cmpax, kHFSPCaseSignature; 'HX'
je.checkBootSignature
;
; Looking for boot1f32 magic string.
;
movax, [kBoot0LoadAddr + kFAT32BootCodeOffset]
cmpax, kBoot1FAT32Magic
jne .exit
.checkBootSignature:
;
; Check for boot block signature 0xAA55
;
mov di, bx
cmp WORD [di + kSectorBytes - 2], kBootSignature
.exit:
popa
ret
;--------------------------------------------------------------------------
; load - Load one or more sectors from a partition.
;
; Arguments:
; AL = number of 512-byte sectors to read.
; ES:BX = pointer to where the sectors should be stored.
; DL = drive number (0x80 + unit number)
; [my_lba] = starting LBA.
;
; Returns:
; CF = 0 success
; 1 error
;
load:
push cx
.ebios:
mov cx, 5 ; load retry count
.ebios_loop:
call read_lba ; use INT13/F42
jnc .exit
loop .ebios_loop
.exit:
pop cx
ret
;--------------------------------------------------------------------------
; read_lba - Read sectors from a partition using LBA addressing.
;
; Arguments:
; AL = number of 512-byte sectors to read (valid from 1-127).
; ES:BX = pointer to where the sectors should be stored.
; DL = drive number (0x80 + unit number)
; [my_lba] = starting LBA.
;
; Returns:
; CF = 0 success
; 1 error
;
read_lba:
pushad ; save all registers
mov bp, sp ; save current SP
;
; Create the Disk Address Packet structure for the
; INT13/F42 (Extended Read Sectors) on the stack.
;
; push DWORD 0 ; offset 12, upper 32-bit LBA
push ds ; For sake of saving memory,
push ds ; push DS register, which is 0.
mov ecx, [my_lba] ; offset 8, lower 32-bit LBA
push ecx
push es ; offset 6, memory segment
push bx ; offset 4, memory offset
xor ah, ah ; offset 3, must be 0
push ax ; offset 2, number of sectors
; It pushes 2 bytes with a smaller opcode than if WORD was used
push BYTE 16 ; offset 0-1, packet size
DebugChar('<')
%if DEBUG
mov eax, ecx
call print_hex
%endif
;
; INT13 Func 42 - Extended Read Sectors
;
; Arguments:
; AH = 0x42
; DL = drive number (80h + drive unit)
; DS:SI = pointer to Disk Address Packet
;
; Returns:
; AH = return status (success is 0)
; carry = 0 success
; 1 error
;
; Packet offset 2 indicates the number of sectors read
; successfully.
;
mov si, sp
mov ah, 0x42
int 0x13
jnc .exit
DebugChar('R') ; indicate INT13/F42 error
;
; Issue a disk reset on error.
; Should this be changed to Func 0xD to skip the diskette controller
; reset?
;
xor ax, ax ; Func 0
int 0x13 ; INT 13
stc ; set carry to indicate error
.exit:
mov sp, bp ; restore SP
popad
ret
;--------------------------------------------------------------------------
; Write a string with 'boot0: ' prefix to the console.
;
; Arguments:
; ES:DI pointer to a NULL terminated string.
;
; Clobber list:
; DI
;
log_string:
pusha
pushdi
movsi, log_title_str
callprint_string
popsi
callprint_string
popa
ret
;--------------------------------------------------------------------------
; Write a string to the console.
;
; Arguments:
; DS:SI pointer to a NULL terminated string.
;
; Clobber list:
; AX, BX, SI
;
print_string:
mov bx, 1 ; BH=0, BL=1 (blue)
cld ; increment SI after each lodsb call
.loop:
lodsb ; load a byte from DS:SI into AL
cmp al, 0 ; Is it a NULL?
je .exit ; yes, all done
mov ah, 0xE ; INT10 Func 0xE
int 0x10 ; display byte in tty mode
jmp short .loop
.exit:
ret
%if DEBUG
;--------------------------------------------------------------------------
; Write a ASCII character to the console.
;
; Arguments:
; AL = ASCII character.
;
print_char:
pusha
mov bx, 1 ; BH=0, BL=1 (blue)
mov ah, 0x0e ; bios INT 10, Function 0xE
int 0x10 ; display byte in tty mode
popa
ret
;--------------------------------------------------------------------------
; Write the 4-byte value to the console in hex.
;
; Arguments:
; EAX = Value to be displayed in hex.
;
print_hex:
pushad
mov cx, WORD 4
bswap eax
.loop:
push ax
ror al, 4
call print_nibble ; display upper nibble
pop ax
call print_nibble ; display lower nibble
ror eax, 8
loop .loop
mov al, 10 ; carriage return
call print_char
mov al, 13
call print_char
popad
ret
print_nibble:
and al, 0x0f
add al, '0'
cmp al, '9'
jna .print_ascii
add al, 'A' - '9' - 1
.print_ascii:
call print_char
ret
getc:
pusha
mov ah, 0
int 0x16
popa
ret
%endif ;DEBUG
;--------------------------------------------------------------------------
; NULL terminated strings.
;
log_title_strdb 10, 13, 'boot0: ', 0
%if VERBOSE
gpt_strdb 'GPT', 0
test_strdb 'test', 0
done_strdb 'done', 0
%endif
boot_error_str db 'error', 0
;--------------------------------------------------------------------------
; Pad the rest of the 512 byte sized booter with zeroes. The last
; two bytes is the mandatory boot sector signature.
;
; If the booter code becomes too large, then nasm will complain
; that the 'times' argument is negative.
;
; According to EFI specification, maximum boot code size is 440 bytes
;
;
; XXX - compilation errors with debug enabled (see comment above about nasm)
; Azi: boot0.s:808: error: TIMES value -111 is negative
; boot0.s:811: error: TIMES value -41 is negative
;
pad_boot:
times 440-($-$$) db 0
pad_table_and_sig:
times 510-($-$$) db 0
dw kBootSignature
ABSOLUTE 0xE400
;
; In memory variables.
;
my_lbaresd1; Starting LBA for read_lba function
; END
trunk/i386/boot0/boot0.s
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;
; @APPLE_LICENSE_HEADER_END@
;
; Boot Loader: boot0
; Boot Loader: boot0xg
;
; A small boot sector program written in x86 assembly whose only
; responsibility is to locate the active partition, load the
;
; In order to coexist with a fdisk partition table (64 bytes), and
; leave room for a two byte signature (0xAA55) in the end, boot0 is
; restricted to 446 bytes (512 - 64 - 2). If boot0 did not have to
; restricted to 440 bytes (512 - 64 - 2 - 6). If boot0 did not have to
; live in the MBR, then we would have 510 bytes to work with.
;
; boot0 is always loaded by the BIOS or another booter to 0:7C00h.
;
; This code is written for the NASM assembler.
; nasm boot0.s -o boot0
; nasm -DCONFIG_BOOT0_DEBUG=? -DCONFIG_BOOT0_VERBOSE=? boot0xg.s -o boot0xg
;
; This version of boot0 implements hybrid GUID/MBR partition scheme support
;
; Added KillerJK's switchPass2 modifications
;
; Modified by Zenith432 November 2014 for exFAT
;
;
; Set to 1 to enable obscure debug messages.
;
DEBUGEQU CONFIG_BOOT0_DEBUG
%define DEBUGCONFIG_BOOT0_DEBUG
;
; Set to 1 to enable verbose mode
;
VERBOSEEQU CONFIG_BOOT0_VERBOSE
%define VERBOSECONFIG_BOOT0_VERBOSE
;
; Various constants.
kHFSPCaseSignatureEQU 'HX'; HFS+ volume case-sensitive signature
kFAT32BootCodeOffset EQU 0x5a; offset of boot code in FAT32 boot sector
kBoot1FAT32MagicEQU 'BO'; Magic string to detect our boot1f32 code
kEXFATBootCodeOffsetEQU 3; offset of exFAT signature in boot sector
kEXFATBootCodeMagicEQU 'EX'; Magic string to detect exFAT
kGPTSignatureLowEQU 'EFI '; GUID Partition Table Header Signature
kPartCountEQU 4; number of paritions per table
kPartTypeHFSEQU 0xaf; HFS+ Filesystem type
kPartTypeABHFSEQU 0xab; Apple_Boot partition
;kPartTypeABHFSEQU 0xab; Apple_Boot partition
kPartTypePMBREQU 0xee; On all GUID Partition Table disks a Protective MBR (PMBR)
; in LBA 0 (that is, the first block) precedes the
; GUID Partition Table Header to maintain compatibility
kPartActive EQU 0x80; active flag enabled
kPartInactive EQU 0x00; active flag disabled
kHFSGUID EQU 0x48465300; first 4 bytes of Apple HFS Partition Type GUID.
;kHFSGUID EQU 0x48465300; first 4 bytes of Apple HFS Partition Type GUID.
kAppleGUIDEQU 0xACEC4365; last 4 bytes of Apple type GUIDs.
kEFISystemGUIDEQU 0x3BC93EC9; last 4 bytes of EFI System Partition Type GUID:
; C12A7328-F81F-11D2-BA4B-00A0C93EC93B
kMicrosoftGUIDEQU 0xC79926B7; last 4 bytes of Microsoft Basic Data Partition Type GUID:
; EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
%ifdef FLOPPY
kDriveNumberEQU 0x00
%else
kDriveNumberEQU 0x80
%endif
;
; Format of fdisk partition entry.
;
mov di, kBoot0RelocAddr ; di <- destination
cld ; auto-increment SI and/or DI registers
mov cx, kSectorBytes/2 ; copy 256 words
repnz movsw ; repeat string move (word) operation
rep movsw ; repeat string move (word) operation
;
; Code relocated, jump to start_reloc in relocated location.
jne .Pass2
.Pass1:
cmp BYTE [si + part.bootid], kPartActive; In pass 1 we are walking on the standard path
test BYTE [si + part.bootid], kPartActive; In pass 1 we are walking on the standard path
; by trying to hop on the active partition.
jne .continue
jz .continue
xor dh, dh ; Argument for loadBootSector to skip HFS+ partition
; signature check.
jmp .tryToBoot
.tryToBoot:
call loadBootSector
jne .continue
jmp SHORT initBootLoader
je SHORT initBootLoader
; fall through to .continue
.continue:
add si, BYTE part_size ; advance SI to next partition entry
checkGPT:
push bx
mov di, kLBA1Buffer; address of GUID Partition Table Header
cmp DWORD [di], kGPTSignatureLow; looking for 'EFI '
mov si, kLBA1Buffer; address of GUID Partition Table Header
cmp DWORD [si], kGPTSignatureLow; looking for 'EFI '
jne .exit; not found. Giving up.
cmp DWORD [di + 4], kGPTSignatureHigh ; looking for 'PART'
cmp DWORD [si + 4], kGPTSignatureHigh ; looking for 'PART'
jne .exit; not found. Giving up indeed.
mov si, di
;
; Loading GUID Partition Table Array
;
cmpeax, kEFISystemGUID; check current GUID Partition for EFI System Partition GUID type
je.gpt_ok
cmpeax, kMicrosoftGUID; check current GUID Partition for Microsoft Basic Data Partition GUID type
jne.gpt_continue
.gpt_ok:
mov si, kMBRPartTable; fake the current GUID Partition
mov [si + part.lba], eax; as MBR style partition for boot1h
mov BYTE [si + part.type], kPartTypeHFS; with HFS+ filesystem type (0xAF)
jmp SHORT initBootLoader
jmp initBootLoader
.gpt_continue:
.checkHFSSignature:
%if VERBOSE
%if 0 && VERBOSE
LogString(test_str)
%endif
je.checkBootSignature
;
; Looking for exFAT signature
;
cmp word [bx + kEXFATBootCodeOffset], kEXFATBootCodeMagic
je.checkBootSignature
;
; Looking for boot1f32 magic string.
;
movax, [kBoot0LoadAddr + kFAT32BootCodeOffset]
cmpax, kBoot1FAT32Magic
cmp word [bx + kFAT32BootCodeOffset], kBoot1FAT32Magic
jne .exit
.checkBootSignature:
;
; Check for boot block signature 0xAA55
;
mov di, bx
cmp WORD [di + kSectorBytes - 2], kBootSignature
cmp WORD [kBoot0LoadAddr + kSectorBytes - 2], kBootSignature
.exit:
%if VERBOSE
gpt_strdb 'GPT', 0
%if 0
test_strdb 'test', 0
%endif
done_strdb 'done', 0
%endif
;
; XXX - compilation errors with debug enabled (see comment above about nasm)
; Azi: boot0.s:808: error: TIMES value -111 is negative
; boot0.s:811: error: TIMES value -41 is negative
; Azi: boot0xg.s:801: error: TIMES value -108 is negative
; boot0xg.s:804: error: TIMES value -38 is negative
;
pad_boot:
times 440-($-$$) db 0
trunk/i386/boot0/Makefile
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DIRS_NEEDED = $(SYMROOT)
OBJS = boot0 boot0hfs boot0md boot0xg chain0
OBJS = boot0 boot0hfs boot0md chain0
OBJS := $(addprefix $(SYMROOT)/, $(OBJS))
all: $(DIRS_NEEDED) $(OBJS)
trunk/CHANGES
1
12
23
34
- Zenith432 : Replace boot0 with boot0xg. Now boot0xg has all features of previous boot0. ( http://www.insanelymac.com/forum/topic/302938-exfat-volume-boot-record-for-chameleon )
- Zenith432 : Completed patch for ExFAT support ( http://www.insanelymac.com/forum/topic/302938-exfat-volume-boot-record-for-chameleon )
- Zenith432 : add EXFAT boot support by Zenith432
- zenith432 : Merge patch from issue 386 (boot2 does not know how to read files from FAT partitions on GPT)

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Revision: 2507