Edit Bios Code Options

[ferrari_rulz_02]

hey all

i got a bit of code i want to inject into a bios. how do i go about opening the bios.bin file so i can insert the text.

is there any compiling i have to do before i can use it?

any help appreciated
cheers

[ferrari_rulz_02]

bit of a bump/more info.

nee this thread, post 257.

i want to insert this code into a BIOS, to force games into 480p.

another question, what would i have to change, to force say 720p?

if you cant be bothered clicking teh link, this is the code i need to insert (thanks dr oldschool)

CODE

patchvideoprogr:
push ebp
mov ebp,esp
push eax
mov eax,[ebp+16]
or eax,eax
js .cont; hdtv mode
jz .640; default mode (?)
test ah,01h
mov eax,88080801h; 720x480p
jz .chng
.640: mov eax,88070701h; 640x480p
.chng: mov [ebp+16],eax
.cont: pop eax
.frame: sub esp,1Ch
VJMP jback

[ferrari_rulz_02]

bump. how do i open a bios.bin file so that i can insert the code i want to?

any help appreciated

[LightningStruckMyXbox]

Think you might have to hex-edit it.

[ferrari_rulz_02]

Think you might have to hex-edit it.

well i tried that. dr oldschool said theyre be heaps of room in the bios (there was, lots of places that are just full of 00 00 00 00 00 00's.

so i whacked it in there, gave it a whirl on the box, but i dont think it worked.

if it did, it would run a non 480p game in 480p. i tried it on colin mcrae rally 3, with no sucsess (i have a hex patched xbe file for it, so i know it should work).

im thinking it is like xbe's, ill need source code for it. hopefully its not

[raydn]

Find a space in the code for the code you want to inject and then...something like this from sheep's Gamehacking Tutorial

CODE

0120:00008096  01585A              ADD     [EAX+5A],EBX

0120:00008099  E9xxxxxxxx    .---- JMP     500000        <--- we create our gateway here...

0120:0000809B  B486          |     MOV     AH,86  <----.

0120:0000809F  55            |     PUSH    EBP         |

0120:000080A0  1E            |     PUSH    DS          |

0120:000080A1  50            |     PUSH    EAX         |

0120:000080A2  E86E078ED8    |     CALL    D88E8815    |

                            |                         |

                            |                         |

0120:00500000  OUR CODE! <---'                         |  

0120:00500002  OUR CODE!                               |

0120:00500004  OUR CODE!                               |

0120:00500006  JMP 809B -------------------------------' <--- once our code is done we jmp back..

[ferrari_rulz_02]

ok then, ill try that, but i got a few questions:

1) this is a bios, it has to be a certian size (256kb). do i just remove some unneeded 00 000's

2) where about does this code need to go? anywhere in particular?

3) di i just do it in a hex editor, and striaght copy over the code i have posted?

[raydn]

REF: http://www.xcheater.com/tutorials/sheep_agtp2.txt

ok then, ill try that, but i got a few questions:

1) this is a bios, it has to be a certian size (256kb). do i just remove some unneeded 00 000's

As far as i know (still learning) I belive so, as long as it the inject the code in a 'code cave' and it doesnt affect the size or anything else.

2) where about does this code need to go? anywhere in particular?

like you said b4 in a space with 00's. find the address of start of this bit you use and asm up a hex jmp to it. Place the hex jump over the code you want to modify. (probably be 5 bytes xx xx xx xx xx) If you replace more than that change the remaining bytes to 90 (nop) and move what you replaced if needed into the jump.

3) di i just do it in a hex editor, and striaght copy over the code i have posted?

think so

[ferrari_rulz_02]

shit man i cant get it to work.

all i can get is no screen and the eject leds to do various things.

raydn, pm'd ya

[ferrari_rulz_02]

ok ive been trying this all wrong.

if i open it up in a hex editor, there is no AvSetDisplayMode in the code.

do i need an uncompiled bios or another program to open it with?

[ferrari_rulz_02]

is this how it has to be done??

id give it a go, but i cant get my hands on a copy of ms visual studio 6

[ferrari_rulz_02]

ok, i cant get my hand son a copy of ms visual studio 6.

what i need is an assembled copy of xbflash. if anyoen can help me out, id love to hear from you.

[heinrich]

what is wrong with just using xbtool to pack/unpack? You can also use nghtshd's biostools, which is based on xbflash.

if i open it up in a hex editor, there is no AvSetDisplayMode in the code.

You'll probably want to find a copy of (or make) an xbox FLIRT file and load up the xbox kernal image in IDA or similiar tool.

[ferrari_rulz_02]

ok, just tried xbtool, and i got this:

CODE

== 10/02/05 16:39:35 == Unpack ==
Loading ROM image file 'C:\Documents and Settings\Daniel\Desktop\bios 480p\ind-bios.5001.06.vga.bfm.bin'...
Extracting 2BL image...
Extracting compressed KERNEL image... Invalid config params for kernel extract!

ill try nghtshd's biostools soon

[ferrari_rulz_02]

ill try nghtshd's biostools soon

ok so xbtool wont work and xbflash doesnt work.

i cant find nghtshd's biostools. i know it illegal to request files..........

ill keep looking but ive tried the usual places