GEN Safe Hooks

[Nice marmite]

What are the safe hooks for GEN D2? I just switched and maybe thats why some of my new jokers dont work...

[Bl4Ck.KiD...]

idk about the other to hooks just A4,CC

[IMIGHTOVERKILL]

yeah Ill try looking into that for you as I use M33 so I dont have any hooking issue.

[Nice marmite]

Thanks for the help :) There is one hook that I know works, but that is for my knife code and I need some more!

[Lavent Sky]

Make a dump of your game and look around the area ps2dis first loads it for any jr ra's those can be some hooks you can use.

[X-dude]

Yea I wanna know some more hooks also cause I heard the CC hook doesnt work and I wanna know so when I update to gen d and can the 0x00000098 hook still work

[Linblow]

GEN = BIG SHIT.

You should use M33 firmware.

Some of my own codes work with M33 whereas they don't work / make the PSP freeze on GEN.

[X-dude]

gen does not suck its just as good as m33 maybe a couple bugs like the hooks but other than that its good

[Nice marmite]

To find hooks search for a jr ra in nitepr and then add them to your cheat DB. If they freeze you when you turn them on they are hooks.

[Linblow]

You know, there are others common hooks between 0x00000000 and 98.
I'm not talking of these : 0x00000024, -4C and -98.

Let's think about a function in MIPs, all functions usually end by a JR command (with RA as the register).

So it means the lines above JR command (in PS2Dis view) can be used to execute a MIPs code.

It's better for you to understand by showing you an example:



Here the functions starts at -2c and it ends at -4c.

So it means all the commands between -2c and -4c are ALWAYS executed (because this function is always executed in the game).

We can "create" new hooks by replacing nop commands with a J command witch points to a routine you wrote.

Why should we use a J command instead of using a JAL command ?
When I tired to put a JAL command, my PSP froze when I turned on the code in nitePR (whereas the routine works perfectly).

I don't know why, maybe my routine wasn't made correctly to be launched by using a JAL command but it works with a J command.

You have to put a nop command between each J command (1 nop after the J). The nop command is reserved to send a variable (loaded into a0, a1, a2 or a3) to the function (aka routine).

This IS NOT correct :




This IS correct :




You have to know something, when you "create" hooks by this way, your routine hasn't to finish by a JR (ra) command.

The last command has to be a J command which goes back to the function where your hook is. Be careful, it goes AFTER the hook you used for this routine (if it goes before, the function you used for hook will not be executed correctly and if you put a JR RA command as last routine command the MIPs code after the hook will not be executed, that's why we have to make a J command which goes back to function ...).

A little example :

My hook is 0x0000003C.

Let's imagine my routine and it starts at 0x00001500 :

lui t0 , $08D1
ori t0 , t0 , $A7D0
lw t2 , $0000(t0)
addiu t3 , t2 , $0001
sw t3 , $0000(t0)

My hook in nitePR looks like that :
0x0000003C 0x0A200540 ( J command $08801500 )

So my routine has to finish by this :
j $08800040 ( goes to 0x00000040, which is the next line after your hook )

Final code is :

#My Routine
0x00001500 0x3C0808D1
0x00001504 0x3508A7D0
0x00001508 0x8D0A0000
0x0000150C 0x254B0001
0x00001510 0xAD0B0000
0x00001514 0x0A200010
0x0000003C 0x0A200540

That works, THIS is the same thing that :

#My Routine
0x00001500 0x3C0808D1
0x00001504 0x3508A7D0
0x00001508 0x8D0A0000
0x0000150C 0x254B0001
0x00001510 0xAD0B0000
0x00001514 0x03E00008
0x0000004C 0x0A200540

The only drawback of this method is that you have to change the J command if you want to use it with another hook.