ReverseEngineering

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==== Tracing ====

See [[ida_pro_tracing]] and [[radare2_tracing]]

==== Other firmares ====

  * [[embedded_controller]]
  * [[intel_amt]]
  * [[video_bios]]

==== Prerequisites ====

1. radare2
  git clone git://github.com/radare/radare2
2. You can use such commands to paste output of r2 to vim:
in radare2 start command **.:8080** and in vim use
  :r!echo x|ncat 127.0.0.1 8080
You should disable color output for that:
  e scr.color=false
  

==== All kind of BIOSes ====

Open bios image just typing

  r2 bios_image.bin

It should be opened automatically, created segment relocation and jumped directly on entry point:

  [f000:fff0]>
  
But, if it not yet recognized automatically, you can do this by your hands:

1. Open bios file with radare2 using this command:

  r2 -e asm.bits=16 -e io.va=true bios_image.bin

2. Do bootblock segment relocation:

  [0x00000000]> S $s-0x10000 0xf000:0x0000 0x10000 0x10000 bootblk rwx

where '$s' - variable, file size (see output of '???' command)

You can also set DOS-like addressing notation:

  [0x00000000]> e asm.segoff=true
  [0000:0000]>

3. go to 0xf000:0xfff0, where BIOS starts

  [0000:0000]> s 0xf000:0xfff0

You can seek also by **s section.bootblk+0xfff0**
Also you can add flags base too:

  [0000:0000]> fb section.bootblk

==== AMIBIOS ====

See example here http://xvilka.me/ami_bios.bin

4. Disassembly, set flag to this as bios_entry

  [f000:fff0]> pd 1; f entry = 0xfff0
  [f000:fff0]> f entry_j 1 0xf000:<addr>
where <addr> shown in previous command
or just run
  [f000:fff0]> f entry_j 1 `pi 1~[2]`
which take addr from that jump automatically

5. Jump table. From previous entry we have found jump to table of jumps.
Int our case it is 34 jumps (found by counting 'jmp' opcode before first 'call' opcode).
'Question 1' - how to count these jumps???
Lets see them:

  [f000:0040]> pd 34
  f000:0040      e9cd00			jmp word 0x111
  f000:0043      e94a5c			jmp word 0x5c90
  f000:0046      e9e50b			jmp word 0xc2e
  f000:0049      e98011			jmp word 0x11cc
  f000:004c      e9a70c			jmp word 0xcf6
  f000:004f      e91246			jmp word 0x4664
  f000:0052      e97710			jmp word 0x10cc
  f000:0055      e9564b			jmp word 0x4bae
  f000:0058      e9624c			jmp word 0x4cbd
  f000:005b      e9c34b			jmp word 0x4c21
  f000:005e      e9df48			jmp word 0x4940
  f000:0061      e94449			jmp word 0x49a8
  f000:0064      e92f57			jmp word 0x5796
  f000:0067      e9e54c			jmp word 0x4d4f
  f000:006a      e9265c			jmp word 0x5c93
  f000:006d      e9bf00			jmp word 0x12f
  f000:0070      e92104			jmp word 0x494
  f000:0073      e9eb05			jmp word 0x661
  f000:0076      e9f105			jmp word 0x66a
  f000:0079      e93c4d			jmp word 0x4db8
  f000:007c      e96f4c			jmp word 0x4cee
  f000:007f      e9cd00			jmp word 0x14f
  f000:0082      e93a48			jmp word 0x48bf
  f000:0085      e9fc52			jmp word 0x5384
  f000:0088      e9cd00			jmp word 0x158
  f000:008b      e9a54a			jmp word 0x4b33
  f000:008e      e9ca00			jmp word 0x15b
  f000:0091      e9ca00			jmp word 0x15e
  f000:0094      e9ca00			jmp word 0x161
  f000:0097      e95211			jmp word 0x11ec
  f000:009a      e9940b			jmp word 0xc31
  f000:009d      e9bf0e			jmp word 0xf5f
  f000:00a0      e9a348			jmp word 0x4946
  f000:00a3      e9d200			jmp word 0x178
  [f000:0040]>

Lets mark these jumps as _j1 - _j34 :
  [f000:0040]>

6. First function from jump table

  [f000:0040]> s 0f000:`pi 1~[2]`
  [f000:0110]> pd
  f000:0110      fa               cli
  f000:0111      fc               cld
  f000:0112      668be0           mov esp, eax
  f000:0115      8cc8             mov ax, cs
  f000:0117      8ed0             mov ss, ax
  f000:0119      668bea           mov ebp, edx
  f000:011c      b0d0             mov al, 0xd0
  f000:011e      e680             out 0x80, al
  f000:0120      bf2601           mov di, 0x126
  f000:0123      e91a04           jmp word 0x540
  f000:0126      8cc8             mov ax, cs
  f000:0128      8ed8             mov ds, ax
  f000:012a      8ec0             mov es, ax
  f000:012c      e914ff           jmp word 0x43
  f000:012f      b0d1             mov al, 0xd1
  f000:0131      e680             out 0x80, al
  f000:0133      b00c             mov al, 0xc
  f000:0135      e661             out 0x61, al
  f000:0137      be9004           mov si, 0x490
  f000:013a      81fe9204         cmp si, 0x492
  f000:013e      730c             jae 0xf014c
   ....

Lets see, what we got:
line **f000:011e out 0x80, al** - POST code, with 0xD0 value in this case
add comment for that:
  [f000:0110]> CCa f000:011e D0 POST CODE

See also line **f000:0120 mov di, 0x126**, where 0x126 is offset to next+1 instuction
Looks suspicios, isnt it? Let see what on addr f000:0540
  [f000:0540]> pd
  f000:0540      6633c0           xor eax, eax
  f000:0543      0fa2             cpuid
  f000:0545      6681fb47656e75   cmp ebx, 0x756e6547
  f000:054c      7404             jz 0xf0552
  f000:054e      fa               cli
  f000:054f      f4               hlt
  f000:0550      ebfc             jmp 0xf054e
  f000:0552      0f08             invd
  f000:0554      0f6eff           movd mm7, edi
  f000:0557      668bc4           mov eax, esp
  f000:055a      e9c806           jmp word 0xc25

Here we are trying to check CPU vendor (0x756e6547 == 'enuG', which is part of 'Genuine Intel'),
one deadloop:
  .-> f000:054f      f4               hlt
  `=< f000:0550      ebfc             jmp 0xf054e

and one local jump:
  f000:054c    jz 0xf0552
  ...
  f000:0552    invd
  ...


=== PCI Access ===

  [f000:12fd]> pd

  f000:12fd      668be2           mov esp, edx
  f000:1300      66c1ec10         shr esp, 0x10
  f000:1304      660f73fa02       pslldq xmm2, 0x2
  f000:1309      660fc4d400       pinsrw xmm2, sp, 0x0
  f000:130e      660f73fa02       pslldq xmm2, 0x2
  f000:1313      660fc4d200       pinsrw xmm2, dx, 0x0
  f000:1318      baf80c           mov dx, 0xcf8
  f000:131b      660d00000080     or eax, 0x80000000
  f000:1321      6683e0fc         and eax, 0xfffffffc
  f000:1325      66ef             out dx, eax
  f000:1327      bafc0c           mov dx, 0xcfc
  f000:132a      668bc3           mov eax, ebx
  f000:132d      66ef             out dx, eax
  f000:132f      660f7ed2         movd edx, xmm2
  f000:1333      660f73da04       psrldq xmm2, 0x4
  f000:1338      660fc5e400       pextrw esp, xmm4, 0x0
  f000:133d      660f73dc02       psrldq xmm4, 0x2
  f000:1342      ffe4             jmp sp

This is **PCI_WriteDword_SSE(uint32_t pci_addr<eax>, uint32_t val<ebx>)** function

  f000:1344      668be1           mov esp, ecx
  f000:1347      66c1ec10         shr esp, 0x10
  f000:134b      660f73f902       pslldq xmm1, 0x2
  f000:1350      660fc4cc00       pinsrw xmm1, sp, 0x0
  f000:1355      660f73f902       pslldq xmm1, 0x2
  f000:135a      660fc4c900       pinsrw xmm1, cx, 0x0
  f000:135f      668be2           mov esp, edx
  f000:1362      66c1ec10         shr esp, 0x10
  f000:1366      660f73fa02       pslldq xmm2, 0x2
  f000:136b      660fc4d400       pinsrw xmm2, sp, 0x0
  f000:1370      660f73fa02       pslldq xmm2, 0x2
  f000:1375      660fc4d200       pinsrw xmm2, dx, 0x0
  f000:137a      8bc8             mov cx, ax
  f000:137c      baf80c           mov dx, 0xcf8
  f000:137f      660d00000080     or eax, 0x80000000
  f000:1385      6683e0fc         and eax, 0xfffffffc
  f000:1389      66ef             out dx, eax
  f000:138b      bafc0c           mov dx, 0xcfc
  f000:138e      83e102           and cx, 0x2
  f000:1391      03d1             add dx, cx
  f000:1393      8bc3             mov ax, bx
  f000:1395      ef               out dx, ax
  f000:1396      660f7ed2         movd edx, xmm2
  f000:139a      660f73da04       psrldq xmm2, 0x4
  f000:139f      660f7ec9         movd ecx, xmm1
  f000:13a3      660f73d904       psrldq xmm1, 0x4
  f000:13a8      660fc5e400       pextrw esp, xmm4, 0x0
  f000:13ad      660f73dc02       psrldq xmm4, 0x2
  f000:13b2      ffe4             jmp sp

This is **PCI_WriteWord_SSE(uint32_t pci_addr<eax>, uint16_t val<bx>)** function

  f000:13b4      668be1           mov esp, ecx
  f000:13b7      66c1ec10         shr esp, 0x10
  f000:13bb      660f73f902       pslldq xmm1, 0x2
  f000:13c0      660fc4cc00       pinsrw xmm1, sp, 0x0
  f000:13c5      660f73f902       pslldq xmm1, 0x2
  f000:13ca      660fc4c900       pinsrw xmm1, cx, 0x0
  f000:13cf      668be2           mov esp, edx
  f000:13d2      66c1ec10         shr esp, 0x10
  f000:13d6      660f73fa02       pslldq xmm2, 0x2
  f000:13db      660fc4d400       pinsrw xmm2, sp, 0x0
  f000:13e0      660f73fa02       pslldq xmm2, 0x2
  f000:13e5      660fc4d200       pinsrw xmm2, dx, 0x0
  f000:13ea      8bc8             mov cx, ax
  f000:13ec      baf80c           mov dx, 0xcf8
  f000:13ef      660d00000080     or eax, 0x80000000
  f000:13f5      6683e0fc         and eax, 0xfffffffc
  f000:13f9      66ef             out dx, eax
  f000:13fb      bafc0c           mov dx, 0xcfc
  f000:13fe      83e103           and cx, 0x3
  f000:1401      03d1             add dx, cx
  f000:1403      8ac3             mov al, bl
  f000:1405      ee               out dx, al
  f000:1406      660f7ed2         movd edx, xmm2
  f000:140a      660f73da04       psrldq xmm2, 0x4
  f000:140f      660f7ec9         movd ecx, xmm1
  f000:1413      660f73d904       psrldq xmm1, 0x4
  f000:1418      660fc5e400       pextrw esp, xmm4, 0x0
  f000:141d      660f73dc02       psrldq xmm4, 0x2
  f000:1422      ffe4             jmp sp

This is **PCI_WriteByte_SSE(uint32_t pci_addr<eax>, uint8_t val<bl>)** function

  f000:1424      668be2           mov esp, edx
  f000:1427      66c1ec10         shr esp, 0x10
  f000:142b      660f73fa02       pslldq xmm2, 0x2
  f000:1430      660fc4d400       pinsrw xmm2, sp, 0x0
  f000:1435      660f73fa02       pslldq xmm2, 0x2
  f000:143a      660fc4d200       pinsrw xmm2, dx, 0x0
  f000:143f      baf80c           mov dx, 0xcf8
  f000:1442      660d00000080     or eax, 0x80000000
  f000:1448      6683e0fc         and eax, 0xfffffffc
  f000:144c      66ef             out dx, eax
  f000:144e      bafc0c           mov dx, 0xcfc
  f000:1451      66ed             in eax, dx
  f000:1453      660f7ed2         movd edx, xmm2
  f000:1457      660f73da04       psrldq xmm2, 0x4
  f000:145c      660fc5e400       pextrw esp, xmm4, 0x0
  f000:1461      660f73dc02       psrldq xmm4, 0x2
  f000:1466      ffe4             jmp sp

=== ROM Call ===

1. Go to **f000:0b3c**

  [f000:0b3c]> pd
  f000:0b3c      8eec             mov gs, sp
  f000:0b3e      8ee3             mov fs, bx
  f000:0b40      bc460b           mov sp, 0xb46
  f000:0b43      e99af8           jmp word 0x3e0
  f000:0b46      48               dec ax
  f000:0b47      0b6681           or sp, [bp-0x7f]
  f000:0b4a      ee               out dx, al

were function, which is calling from f000:0b43 (jmp word f000:0x3e0) is **get_decomp_block_size**

  [f000:03e0]> pd
  f000:03e0      662e8b0ed7ff     mov ecx, [cs:0xffd7]
  f000:03e6      668bf1           mov esi, ecx
  f000:03e9      66f7de           neg esi
  f000:03ec      c3               ret
  ;--------------

So, we have jmp to function, which is to near return. This is ROM call convention
(see book from Darmawan Salihun). So, we need fix previous function to properly handle it.
We are placing **0xb46** to **sp** before jump. This mean, that code at f000:0b46 should be word data:

  f000:0b46      48               dec ax
  f000:0b47      0b6681           or sp, [bp-0x7f]
  f000:0b4a      ee               out dx, al

**48 0b** - here our word. This mean, that rest of code completely wrong. Lets fix that.
  [f000:0b3c]> Cd 2 @ f000:0b46

==== Award ====

==== Phoenix ====

Download example from http://xvilka.me/asrock_p4i65g.bin and open it as usual.

... [some reversing process]...

SMBus reading/writing. So, we've found some SMBus function, and we know, that 0x5786 - offset of **SMBus_ICH5_Reg_Write_Byte_SL** function, and 0x578e - offset of **SMBus_ICH5_Reg_Read_Byte_SL** function.

  [f000:574d]> pd 24
            f000:574d      b8d304           mov ax, 0x4d3
            f000:5750      bf5557           mov di, 0x5755
        ,=< f000:5753      eb31             jmp 0x5786
        |   f000:5755      66c1c008         rol eax, 0x8
        |   f000:5759      0c80             or al, 0x80
        |   f000:575b      b403             mov ah, 0x3
        |   f000:575d      bf6257           mov di, 0x5762
       ,==< f000:5760      eb24             jmp 0x5786
       ||   f000:5762      b84802           mov ax, 0x248
       ||   f000:5765      bf6a57           mov di, 0x576a
      ,===< f000:5768      eb1c             jmp 0x5786
      |||   f000:576a      b93075           mov cx, 0x7530
      |||   f000:576d      e6ed             out 0xed, al
      |||   f000:576f      e2fc             loop 0x576d
      |||   f000:5771      b8ff00           mov ax, 0xff
      |||   f000:5774      bf7957           mov di, 0x5779
     ,====< f000:5777      eb0d             jmp 0x5786
     ||||   f000:5779      b405             mov ah, 0x5
     ||||   f000:577b      bf8057           mov di, 0x5780
     ||||   f000:577e      eb0e             jmp 0x578e
     ||||   f000:5780      660fcf           bswap edi
     ||||   f000:5783      f8               clc
     ||||   f000:5784      ffe7             jmp di
     ||||   ; -------- SMBus_ICH5_Reg_Write_Byte_SL:
     ````-> f000:5786      ba0004           mov dx, 0x400

Add these functions:
  [f000:574d]> af+ f000:5786 8 SMBus_ICH5_Reg_Write_Byte_SL
  [f000:574d]> af+ f000:578e 8 SMBus_ICH5_Reg_Read_Byte_SL
where 8 - size of both functions in bytes. "_SL" prefix means "stackless" (just my internal notation).

Lets add more metainfo, comments and so on:

  [f000:574d]> "CCa f000:5786 void SMBus_ICH5_Reg_Write_Byte_SL(uint8_t reg<ah>, uint8_t value<al>);"
  [f000:574d]> "CCa f000:578e uint8_t SMBus_ICH5_Reg_Read_Byte_SL<al>(uint8_t reg<ah>);"

Note, that you should quote **whole** r2 command to mask special symbols **';'**, **'>'** and **'<'**.
Then add few comments:
  [f000:574d]> "CCa 0xf000:0x574d value = 0xD3; reg = 0x4; // XMIT_SLVA - Transmit Slave Address"
  [f000:574d]> "CCa 0xf000:0x575b reg = 0x3; // HST_CMD - Host Command"
  [f000:574d]> "CCa 0xf000:0x5762 value = 0x48; reg = 0x2; // HST_CNT - Host Control"
  
Also add these local labels:
  [f000:574d]> f SMB_Send_CMD 1 0xf000:0x5755
  [f000:574d]> f SMB_Prepare_Controller 1 0xf000:0x5762
  [f000:574d]> f SMB_Read_Data 1 0xf000:0x5779
  [f000:574d]> f SMB_delay_loop 1 0xf000:0x576d
  
And here is what we have got (in VISUAL mode - **Vp** command to enter):

  [0x000f574d 255 asrock_p4i65g.bin]> pd $h                                                                                                                                 
    ;              ; value = 0xD3; reg = 0x4; // XMIT_SLVA - Transmit Slave Address                                                                                         
              f000:574d      b8d304           mov ax, 0x4d3                                                                                                                 
              f000:5750      bf5557           mov di, 0x5755                                                                                                                
          ,=< f000:5753      eb31             jmp 0x5786                                                                                                                    
          |   ; -------- SMB_Send_CMD:                                                                                                                                      
          |   f000:5755      66c1c008         rol eax, 0x8                                                                                                                  
          |   f000:5759      0c80             or al, 0x80                                                                                                                   
    ;              ; value = 0x3; // HST_CMD - Host Command                                                                                                                 
          |   f000:575b      b403             mov ah, 0x3                                                                                                                   
          |   f000:575d      bf6257           mov di, 0x5762                                                                                                                
         ,==< f000:5760      eb24             jmp 0x5786                                                                                                                    
    ;              ; value = 0x48; reg = 0x2; // HST_CNT - Host Control                                                                                                     
         ||   ; -------- SMB_Prepare_Controller:                                                                                                                            
         ||   f000:5762      b84802           mov ax, 0x248                                                                                                                 
         ||   f000:5765      bf6a57           mov di, 0x576a                                                                                                                
        ,===< f000:5768      eb1c             jmp 0x5786                                                                                                                    
        |||   f000:576a      b93075           mov cx, 0x7530                                                                                                                
        |||   ; -------- SMB_delay_loop:                                                                                                                                    
        |||   f000:576d      e6ed             out 0xed, al                                                                                                                  
        |||   f000:576f      e2fc             loop 0x576d                                                                                                                   
        |||   f000:5771      b8ff00           mov ax, 0xff                                                                                                                  
        |||   f000:5774      bf7957           mov di, 0x5779                                                                                                                
       ,====< f000:5777      eb0d             jmp 0x5786                                                                                                                    
       ||||   ; -------- SMB_Read_Data:                                                                                                                                     
       ||||   f000:5779      b405             mov ah, 0x5                                                                                                                   
       ||||   f000:577b      bf8057           mov di, 0x5780                                                                                                                
      ,=====< f000:577e      eb0e             jmp 0x578e                                                                                                                    
      |||||   f000:5780      660fcf           bswap edi                                                                                                                     
      |||||   f000:5783      f8               clc                                                                                                                           
      |||||   f000:5784      ffe7             jmp di                                                                                                                        
    ;              ; void SMBus_ICH5_Reg_Write_Byte_SL(uint8_t reg<ah>, uint8_t value<al>);                                                                                            
  / function: SMBus_ICH5_Reg_Write_Byte_SL (8)                                                                                                                                         
  |   |````-> f000:5786      ba0004           mov dx, 0x400                                                                                                                 
  |   |       f000:5789      8ad4             mov dl, ah                                                                                                                    
  |   |       f000:578b      ee               out dx, al                                                                                                                    
  \   |       f000:578c      ffe7             jmp di                                                                                                                        
    ;              ; uint8_t SMBus_ICH5_Reg_Read_Byte_SL<al>(uint8_t reg<ah>);                                                                                                         
  / function: SMBus_ICH5_Reg_Read_Byte_SL (8)                                                                                                                                          
  |   `-----> f000:578e      ba0004           mov dx, 0x400                                                                                                                 
  |           f000:5791      8ad4             mov dl, ah                                                                                                                    
  |           f000:5793      ec               in al, dx                                                                                                                     
  \           f000:5794      ffe7             jmp di                                                                                                                        
     ,======< f000:5796      7426             jz 0x57be                                                                                                                     
     |        f000:5798      b87000           mov ax, 0x70                                                                                                                  
     |        f000:579b      90               nop                                                                                                                           
     |        f000:579c      bca257           mov sp, 0x57a2                                                                                                                
     |        f000:579f      e9b9f2           jmp 0x4a5b                                                                                                                    
     |        f000:57a2      a4               movsb                                                                                                                         
     |        f000:57a3      57               push di                                                                                                                       
     |        f000:57a4      b87200           mov ax, 0x72                                                                                                                  

==== HP BIOS ====

See example here http://xvilka.me/hp_bios.bin

1. Disassembly, set flag to this as bios_entry

Note, that instead of long jump HP bioses widely using short jumps, so you should add **0xf000:** prefix in these jumps.

  [f000:fff0]> pd 1; f entry = 0xfff0
  [f000:fff0]> f entry_j 1 0xf000:<addr>
where <addr> shown in previous command
or just run
  [f000:fff0]> f entry_j 1 0f000:`pi 1~[2]`
which take addr from that jump automatically

==== UEFI ====

=== Phoenix ===

See example here http://xvilka.me/phx_uefi.bin

1. Open bios file with radare2 using this command:
  r2 -e asm.bits=32 -e io.va=true phx_uefi.bin
You should choose valid asm.bits value due to arch of image.

2. Do bootblock segment relocation:
  [0x00000000]> S $s-0x10000 0xf000:0x0000 0x10000 0x10000 bootblk rwx
where '$s' - variable, file size (see output of '???' command)

Then set this as 16bit segment
  [0x00000000]> Sa x86 16 @ 0xf000:0x0000
You can check result by typing just 'S' command.

You can also set DOS-like addressing notation:
  [0x00000000]> e asm.segoff=true
  [0000:0000]>

3. go to 0xf000:0xfff0, where BIOS starts
  [0000:0000]> s 0xf000:0xfff0

You can seek also by **s section.bootblk+0xfff0**
Also you can add flags base too:
  [0000:0000]> fb section.bootblk

4. Disassembly, set flag to this as bios_entry

  [f000:fff0]> pd 1; f entry = 0xfff0
  f000:fff0      e908ff       jmp word 0xfefb

  [f000:fff0]> f entry_j 1 <addr>
where <addr> shown in previous command
or just run
  [f000:fff0]> f entry_j 1 0xf000:`pi 1~[2]`
which take addr from that jump automatically

5. Go to **entry_j**

  [f000:fff0]> s entry_j; pd 1
  ; -------- entry_j:
            f000:fefb      e913fd       jmp word 0xfc11
Call it 'boot' for example:
  [f000:fefb]> f boot 1 0xf000:fc11
Then go to this addr **s boot** and do disassembly:
  [f000:fc11]> s boot; pd
          ; -------- boot:
          0x000ffc11      66b801000000     mov eax, 0x1
          0x000ffc17      0fa2             cpuid
          0x000ffc19      660fbaea1a       bts edx, 0x1a
      ,=< 0x000ffc1e      7309             jae 0xffc29
      |   0x000ffc20      0f20e0           mov eax, cr4
      |   0x000ffc23      80cc02           or ah, 0x2
      |   0x000ffc26      0f22e0           mov cr4, eax
      `-> 0x000ffc29      6633c0           xor eax, eax
          0x000ffc2c      fec0             inc al
          0x000ffc2e      0fa2             cpuid
          0x000ffc30      6625f00fff0f     and eax, 0xfff0ff0
          0x000ffc36      663d70060100     cmp eax, 0x10670
     ,==< 0x000ffc3c      7408             jz 0xffc46
     |    0x000ffc3e      3df006           cmp ax, 0x6f0
    ,===< 0x000ffc41      7403             jz 0xffc46
    ||    0x000ffc43      e9b802           jmp word 0xfefe
    ``--> 0x000ffc46      b060             mov al, 0x60
          0x000ffc48      ba7000           mov dx, 0x70
          0x000ffc4b      ee               out dx, al
          0x000ffc4c      e6ed             out 0xed, al
          0x000ffc4e      ba7100           mov dx, 0x71
          0x000ffc51      ec               in al, dx
          0x000ffc52      0fbae800         bts ax, 0x0
          0x000ffc56      0f82a402         jb word 0xfefe
          0x000ffc5a      66b9ee000000     mov ecx, 0xee
          0x000ffc60      0f32             rdmsr
          0x000ffc62      0fbae802         bts ax, 0x2
          0x000ffc66      0f30             wrmsr
          0x000ffc68      e99302           jmp word 0xfefe
Here we're checking for CPU family and features
          0x000ffc6b      66b801000000     mov eax, 0x1
          0x000ffc71      0fa2             cpuid
          0x000ffc73      668bc8           mov ecx, eax
          0x000ffc76      67268b46ec       mov ax, [es:esi-0x14]
          0x000ffc7b      83e818           sub ax, 0x18
          0x000ffc7e      bb0008           mov bx, 0x800
          0x000ffc81      33d2             xor dx, dx
          0x000ffc83      f7f3             div bx
          0x000ffc85      668bd1           mov edx, ecx
          0x000ffc88      8bc8             mov cx, ax
          0x000ffc8a      67662639560c     cmp [es:esi+0xc], edx
      ,=< 0x000ffc90      7514             jnz 0xffca6
      |   0x000ffc92      66b979000000     mov ecx, 0x79
      |   0x000ffc98      668bc6           mov eax, esi
      |   0x000ffc9b      6683c030         add eax, 0x30
      |   0x000ffc9f      6633d2           xor edx, edx
      |   0x000ffca2      0f30             wrmsr
     ,==< 0x000ffca4      eb09             jmp 0xffcaf
     |`-> 0x000ffca6      6681c600080000   add esi, 0x800
     |    0x000ffcad      e2db             loop 0xffc8a
     `--> 0x000ffcaf      66b9a0010000     mov ecx, 0x1a0
          0x000ffcb5      0f32             rdmsr
          0x000ffcb7      6683e0fe         and eax, 0xfffffffe
          0x000ffcbb      0f30             wrmsr
          0x000ffcbd      e97702           jmp word 0xff37
          0x000ffcc0      66b801000000     mov eax, 0x1
          0x000ffcc6      0fa2             cpuid
          0x000ffcc8      80e40f           and ah, 0xf
          0x000ffccb      80fc0f           cmp ah, 0xf
          0x000ffcce      7504             jnz 0xffcd4
      ,=< 0x000ffcd0      eb13             jmp 0xffce5
      |   0x000ffcd2      eb0e             jmp 0xffce2
      |   0x000ffcd4      80fc06           cmp ah, 0x6
     ,==< 0x000ffcd7      7505             jnz 0xffcde
     ||   0x000ffcd9      e9bc00           jmp word 0xfd98

=== AMI (Aptio) ===

=== Insyde ===
ReverseEngineering

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