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gerrit.devboardsforandroid.linaro.org / device / linaro / hikey960 / 82c807137a2c3f033e23e414476d131e88ad221a / . / uefi / linaro-edk2 / DuetPkg / BootSector / Gpt.asm
blob: e94075308d0d7da7375f3c34432afefd191626a6 [file] [log] [blame]
Vishal Bhoj82c80712015-12-15 21:13:33 +0530[diff] [blame^]1;------------------------------------------------------------------------------
2;*
3;* Copyright (c) 2006 - 2007, Intel Corporation. All rights reserved.<BR>
4;* This program and the accompanying materials
5;* are licensed and made available under the terms and conditions of the BSD License
6;* which accompanies this distribution. The full text of the license may be found at
7;* http://opensource.org/licenses/bsd-license.php
8;*
9;* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10;* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
11;*
12;* gpt.asm
13;*
14;* Abstract:
15;*
16;------------------------------------------------------------------------------
17
18 .model small
19; .dosseg
20 .stack
21 .486p
22 .code
23
24BLOCK_SIZE EQU 0200h
25BLOCK_MASK EQU 01ffh
26BLOCK_SHIFT EQU 9
27
28; ****************************************************************************
29; Code loaded by BIOS at 0x0000:0x7C00
30; ****************************************************************************
31
32 org 0h
33Start:
34
35; ****************************************************************************
36; Start Print
37; ****************************************************************************
38
39 mov ax,0b800h
40 mov es,ax
41 mov ax, 07c0h
42 mov ds, ax
43 lea si, cs:[StartString]
44 mov cx, 10
45 mov di, 160
46 rep movsw
47
48; ****************************************************************************
49; Print over
50; ****************************************************************************
51
52; ****************************************************************************
53; Initialize segment registers and copy code at 0x0000:0x7c00 to 0x0000:0x0600
54; ****************************************************************************
55 xor ax, ax ; AX = 0x0000
56 mov bx, 07c00h ; BX = 0x7C00
57 mov bp, 0600h ; BP = 0x0600
58 mov si, OFFSET RelocatedStart ; SI = Offset(RelocatedStart)
59 mov cx, 0200h ; CX = 0x0200
60 sub cx, si ; CS = 0x0200 - Offset(RelocatedStart)
61 lea di, [bp+si] ; DI = 0x0600 + Offset(RelocatedStart)
62 lea si, [bx+si] ; BX = 0x7C00 + Offset(RelocatedStart)
63 mov ss, ax ; SS = 0x0000
64 mov sp, bx ; SP = 0x7C00
65 mov es,ax ; ES = 0x0000
66 mov ds,ax ; DS = 0x0000
67 push ax ; PUSH 0x0000
68 push di ; PUSH 0x0600 + Offset(RelocatedStart)
69 cld ; Clear the direction flag
70 rep movsb ; Copy 0x0200 bytes from 0x7C00 to 0x0600
71 retf ; JMP 0x0000:0x0600 + Offset(RelocatedStart)
72
73; ****************************************************************************
74; Code relocated to 0x0000:0x0600
75; ****************************************************************************
76
77RelocatedStart:
78; ****************************************************************************
79; Get Driver Parameters to 0x0000:0x7BFC
80; ****************************************************************************
81 xor ax,ax ; ax = 0
82 mov ss,ax ; ss = 0
83 add ax,1000h
84 mov ds,ax
85
86 mov sp,07c00h ; sp = 0x7c00
87 mov bp,sp ; bp = 0x7c00
88
89 mov ah,8 ; ah = 8 - Get Drive Parameters Function
90 mov byte ptr [bp+PhysicalDrive],dl ; BBS defines that BIOS would pass the booting driver number to the loader through DL
91 int 13h ; Get Drive Parameters
92 xor ax,ax ; ax = 0
93 mov al,dh ; al = dh
94 inc al ; MaxHead = al + 1
95 push ax ; 0000:7bfe = MaxHead
96 mov al,cl ; al = cl
97 and al,03fh ; MaxSector = al & 0x3f
98 push ax ; 0000:7bfc = MaxSector
99
100; ****************************************************************************
101; Read GPT Header from hard disk to 0x0000:0x0800
102; ****************************************************************************
103 xor ax, ax
104 mov es, ax ; Read to 0x0000:0x0800
105 mov di, 0800h ; Read to 0x0000:0x0800
106 mov eax, 1 ; Read LBA #1
107 mov edx, 0 ; Read LBA #1
108 mov bx, 1 ; Read 1 Block
109 push es
110 call ReadBlocks
111 pop es
112
113; ****************************************************************************
114; Read Target GPT Entry from hard disk to 0x0000:0x0A00
115; ****************************************************************************
116 cmp dword ptr es:[di], 020494645h ; Check for "EFI "
117 jne BadGpt
118 cmp dword ptr es:[di + 4], 054524150h ; Check for "PART"
119 jne BadGpt
120 cmp dword ptr es:[di + 8], 000010000h ; Check Revision - 0x10000
121 jne BadGpt
122
123 mov eax, dword ptr es:[di + 84] ; EAX = SizeOfPartitionEntry
124 mul byte ptr [bp+GptPartitionIndicator] ; EAX = SizeOfPartitionEntry * GptPartitionIndicator
125 mov edx, eax ; EDX = SizeOfPartitionEntry * GptPartitionIndicator
126 shr eax, BLOCK_SHIFT ; EAX = (SizeOfPartitionEntry * GptPartitionIndicator) / BLOCK_SIZE
127 and edx, BLOCK_MASK ; EDX = Targer PartitionEntryLBA Offset
128 ; = (SizeOfPartitionEntry * GptPartitionIndicator) % BLOCK_SIZE
129 push edx
130 mov ecx, dword ptr es:[di + 72] ; ECX = PartitionEntryLBA (Low)
131 mov ebx, dword ptr es:[di + 76] ; EBX = PartitionEntryLBA (High)
132 add eax, ecx ; EAX = Target PartitionEntryLBA (Low)
133 ; = (PartitionEntryLBA +
134 ; (SizeOfPartitionEntry * GptPartitionIndicator) / BLOCK_SIZE)
135 adc edx, ebx ; EDX = Target PartitionEntryLBA (High)
136
137 mov di, 0A00h ; Read to 0x0000:0x0A00
138 mov bx, 1 ; Read 1 Block
139 push es
140 call ReadBlocks
141 pop es
142
143; ****************************************************************************
144; Read Target DBR from hard disk to 0x0000:0x7C00
145; ****************************************************************************
146 pop edx ; EDX = (SizeOfPartitionEntry * GptPartitionIndicator) % BLOCK_SIZE
147 add di, dx ; DI = Targer PartitionEntryLBA Offset
148 cmp dword ptr es:[di], 0C12A7328h ; Check for EFI System Partition "C12A7328-F81F-11d2-BA4B-00A0C93EC93B"
149 jne BadGpt
150 cmp dword ptr es:[di + 4], 011d2F81Fh ;
151 jne BadGpt
152 cmp dword ptr es:[di + 8], 0A0004BBAh ;
153 jne BadGpt
154 cmp dword ptr es:[di + 0ch], 03BC93EC9h ;
155 jne BadGpt
156
157 mov eax, dword ptr es:[di + 32] ; EAX = StartingLBA (Low)
158 mov edx, dword ptr es:[di + 36] ; EDX = StartingLBA (High)
159 mov di, 07C00h ; Read to 0x0000:0x7C00
160 mov bx, 1 ; Read 1 Block
161 call ReadBlocks
162
163; ****************************************************************************
164; Transfer control to BootSector - Jump to 0x0000:0x7C00
165; ****************************************************************************
166 xor ax, ax
167 push ax ; PUSH 0x0000
168 mov di, 07c00h
169 push di ; PUSH 0x7C00
170 retf ; JMP 0x0000:0x7C00
171
172; ****************************************************************************
173; ReadBlocks - Reads a set of blocks from a block device
174;
175; EDX:EAX = Start LBA
176; BX = Number of Blocks to Read (must < 127)
177; ES:DI = Buffer to store sectors read from disk
178; ****************************************************************************
179
180; si = DiskAddressPacket
181
182ReadBlocks:
183 pushad
184 push ds
185 xor cx, cx
186 mov ds, cx
187 mov bp, 0600h ; bp = 0x600
188 lea si, [bp + OFFSET AddressPacket] ; DS:SI = Disk Address Packet
189 mov BYTE PTR ds:[si+2],bl ; 02 = Number Of Block transfered
190 mov WORD PTR ds:[si+4],di ; 04 = Transfer Buffer Offset
191 mov WORD PTR ds:[si+6],es ; 06 = Transfer Buffer Segment
192 mov DWORD PTR ds:[si+8],eax ; 08 = Starting LBA (Low)
193 mov DWORD PTR ds:[si+0ch],edx ; 0C = Starting LBA (High)
194 mov ah, 42h ; ah = Function 42
195 mov dl,byte ptr [bp+PhysicalDrive] ; dl = Drive Number
196 int 13h
197 jc BadGpt
198 pop ds
199 popad
200 ret
201
202; ****************************************************************************
203; Address Packet used by ReadBlocks
204; ****************************************************************************
205AddressPacket:
206 db 10h ; Size of address packet
207 db 00h ; Reserved. Must be 0
208 db 01h ; Read blocks at a time (To be fixed each times)
209 db 00h ; Reserved. Must be 0
210 dw 0000h ; Destination Address offset (To be fixed each times)
211 dw 0000h ; Destination Address segment (To be fixed each times)
212AddressPacketLba:
213 dd 0h, 0h ; Start LBA (To be fixed each times)
214AddressPacketEnd:
215
216; ****************************************************************************
217; ERROR Condition:
218; ****************************************************************************
219
220BadGpt:
221 mov ax,0b800h
222 mov es,ax
223 mov ax, 060h
224 mov ds, ax
225 lea si, cs:[ErrorString]
226 mov cx, 10
227 mov di, 320
228 rep movsw
229Halt:
230 jmp Halt
231
232StartString:
233 db 'G', 0ch, 'P', 0ch, 'T', 0ch, ' ', 0ch, 'S', 0ch, 't', 0ch, 'a', 0ch, 'r', 0ch, 't', 0ch, '!', 0ch
234ErrorString:
235 db 'G', 0ch, 'P', 0ch, 'T', 0ch, ' ', 0ch, 'E', 0ch, 'r', 0ch, 'r', 0ch, 'o', 0ch, 'r', 0ch, '!', 0ch
236
237; ****************************************************************************
238; PhysicalDrive - Used to indicate which disk to be boot
239; Can be patched by tool
240; ****************************************************************************
241 org 01B6h
242PhysicalDrive db 80h
243
244; ****************************************************************************
245; GptPartitionIndicator - Used to indicate which GPT partition to be boot
246; Can be patched by tool
247; ****************************************************************************
248 org 01B7h
249GptPartitionIndicator db 0
250
251; ****************************************************************************
252; Unique MBR signature
253; ****************************************************************************
254 org 01B8h
255 db 'DUET'
256
257; ****************************************************************************
258; Unknown
259; ****************************************************************************
260 org 01BCh
261 dw 0
262
263; ****************************************************************************
264; PMBR Entry - Can be patched by tool
265; ****************************************************************************
266 org 01BEh
267 db 0 ; Boot Indicator
268 db 0ffh ; Start Header
269 db 0ffh ; Start Sector
270 db 0ffh ; Start Track
271 db 0eeh ; OS Type
272 db 0ffh ; End Header
273 db 0ffh ; End Sector
274 db 0ffh ; End Track
275 dd 1 ; Starting LBA
276 dd 0FFFFFFFFh ; End LBA
277
278 org 01CEh
279 dd 0, 0, 0, 0
280 org 01DEh
281 dd 0, 0, 0, 0
282 org 01EEh
283 dd 0, 0, 0, 0
284
285; ****************************************************************************
286; Sector Signature
287; ****************************************************************************
288
289 org 01FEh
290SectorSignature:
291 dw 0aa55h ; Boot Sector Signature
292
293 end
294