Guide:Writing pnach files

This guide contains documentation on how to write patch lines in pnach format.

Format

Pnach format takes inspiration from RAW PS2 cheat codes. A RAW PS2 cheat code is composed of 2 valid hexadecimal numbers (0-9, A-F), without the prefix "0x" and always composed of 8 digits:

XXXXXXXX YYYYYYYY

To convert a RAW PS2 cheat code to a patch line to be used in a pnach file, one must add "patch=1,EE," before the first number and ",extended," before the second number:

patch=1,EE,XXXXXXXX,extended,YYYYYYYY

For example, a RAW PS2 cheat code could be:

00E98100 00000064

Converted to pnach-format:

patch=1,EE,00E98100,extended,00000064

This patch line will constantly write the 8-bit value 0x64 to the address 0xE98100.

Pnach format supports single-line ("//") comments. This means that prefixing a patch line with "//" it will be ignored.

So, we can say that a pnach file is a sequence of patch lines.

Below you can find the documentation of the code types available with their respective syntax.

Constant write

8-bit constant write

Writes the 8-bit value @v to the address @a.

0aaaaaaa 000000vv

16-bit constant write

Writes the 16-bit value @v to the address @a.

1aaaaaaa 0000vvvv

32-bit constant write

Writes the 32-bit value @v to the address @a.

2aaaaaaa vvvvvvvv

Increment / Decrement

Increment/decrement the current value at address @a by value @v.

8-bit increment

300000vv 0aaaaaaa

8-bit decrement

301000vv 0aaaaaaa

16-bit increment

3020vvvv 0aaaaaaa

16-bit decrement

3030vvvv 0aaaaaaa

32-bit increment

30400000 0aaaaaaa
vvvvvvvv 00000000

32-bit decrement

30500000 0aaaaaaa
vvvvvvvv 00000000

Constant serial write

8-bit constant serial write

Starting with address @a, this code writes the 8-bit value @v to @n addresses.

In each cycle, the address is incremented by @s * 2 and the value is incremented by @i.

8aaaaaaa nnnnssss
000000vv 000000ii

16-bit constant serial write

Starting with address @a, this code writes the 16-bit value @v to @n addresses.

In each cycle, the address is incremented by @s * 2 and the value is incremented by @i.

8aaaaaaa nnnnssss
1000vvvv 0000iiii

32-bit constant serial write

Starting with address @a, this code writes the 32-bit value @v to @n addresses.

In each cycle, the address is incremented by @s * 4 and the value is incremented by @i.

4aaaaaaa nnnnssss
vvvvvvvv iiiiiiii

Copy bytes

Copies a block of @n bytes from source address @s to destination address @d.

5sssssss nnnnnnnn
0ddddddd 00000000

Pointer write

This code reads a pointer address @a, follows it @n pointers deep, and writes the @v value to the calculated address.

NOTE: Execution of this code type will stop if a NULL pointer is encountered to prevent a crash.

Single dereference (n <= 1)

Loads the 32-bit base address from address @a, adds offset @p_0 to it, and constantly writes the value @v to the calculated address.

Multiple dereferences (n > 1)

Loads the 32-bit base address from address @a, adds offset @p_0 to it to get an initial pointer address P_0. Dereference P_0 and add @p_1 to the result to get the next pointer address P_1. This is done @n times until the final address P_n is found, at which point the value @v is written to the calculated address.

8-bit pointer write

6aaaaaaa 000000vv
0000nnnn    p_0
   p_1      p_2
........ ........
 p_(n-1)    p_n

16-bit pointer write

6aaaaaaa 0000vvvv
0001nnnn    p_0
   p_1      p_2
........ ........
 p_(n-1)    p_n

32-bit pointer write

6aaaaaaa vvvvvvvv
0002nnnn    p_0
   p_1      p_2
........ ........
 p_(n-1)    p_n

Bitwise operations

Performs a bitwise logical operation between the value @v and the value stored at address @a. Store the result at address @a.

8-bit OR

7aaaaaaa 000000vv

16-bit OR

7aaaaaaa 0010vvvv

8-bit AND

7aaaaaaa 002000vv

16-bit AND

7aaaaaaa 0030vvvv

8-bit XOR

7aaaaaaa 004000vv

16-bit XOR

7aaaaaaa 0050vvvv

Conditionals

C-Type

32-bit execute all following codes if equal to

All following codes will be executed only if 32-bit value at address @a is equal to the value @v.

Caaaaaaa vvvvvvvv

D-Type (NOT RECOMMENDED)

Multi-line "if"

Compares value at address @a to value @v, and executes next @n lines only if the test condition @t is true. Values for @t are:

• 0 equal
• 1 not equal
• 2 less than
• 3 greater than
• 4 NAND
• 5 AND
• 6 NOR
• 7 OR

8-bit test

Daaaaaaa nnt100vv

16-bit test

Daaaaaaa nnt0vvvv

E-Type (RECOMMENDED)

Multi-line "if"

Compares value at address @a to value @v, and executes next @n lines only if the test condition @t is true. Values for @t are:

• 0 equal
• 1 not equal
• 2 less than
• 3 greater than
• 4 NAND
• 5 AND
• 6 NOR
• 7 OR

8-bit test

E1nn00vv taaaaaaa

16-bit test

E0nnvvvv taaaaaaa