Creating custom ROMs for the PS2

[mknrls]

If i understood correctly a modded bios on 9000 series (for example) would remove the need of a mod chip,
then setting up ps2bbl to open our preferred application .ELF ?

 

[Epaminondas]

yes, .ELF files can be called from within the ROM.

 

[uyjulian]

In-system ROM flashing tool is now up on Github, in romflash repository under ps2dbg organization.

 

[tna9rish]

In-system ROM flashing tool is now up on Github, in romflash repository under ps2dbg organization.

Hey I would say thanks for this awesome stuff . But I don't know how to flash the bios with the tool you said. Now how do I flash the bios on my ps2 ?? and which hardware do I need to do it ?? . and thanks in advance

 

[Epaminondas]

Flash Tool would be software tools for building new ROM images. A new application for this is currently under development. However, to have this on the console, the original BIOS chip must be replaced with a new chip with a custom ROM. Examples of chips that work are: MX29LV320, MX29LV640. These are the ones I use, but I believe others can also be used. You have to check the datasheet.

The original PS2 ROM chip cannot be re-flashed.

 

[tna9rish]

Flash Tool would be software tools for building new ROM images. A new application for this is currently under development. However, to have this on the console, the original BIOS chip must be replaced with a new chip with a custom ROM. Examples of chips that work are: MX29LV320, MX29LV640. These are the ones I use, but I believe others can also be used. You have to check the datasheet.

The original PS2 ROM chip cannot be re-flashed.

Thank you so much for the info . I know the ps2 rom in read only .But anyway really thanks for the efforts .

 

[tna9rish]

Anyway I tried the bios of a 9K model on the pcsx2 emulator and it worked only that opl keeps loading . Also I tried the file that inside the folder where there is many files coz the file that generated output inside the custom just crashes the emulator .

 

[Armorant]

Edited: 11 of feb 2026
DO NOT USE THAT DESIGN!
IT WORKS on 70k - yes, but that one is complex and do need another extra PCB to work (added gerbers for PCB-fix).
....
Designed to be installed on unpopulated TSOP-2-44 footprints (separate BOOT and DVD flashes). Mostly for GH-032/035, maybe 037. I hope that by using a 1.90 NTSC-U bios I would restore FHDB for 70k (confirmed) and get pros for MechaPWN'ed PAL consoles (not confirmed).
To install you need to remove TSOP-2-50 combined BOOTROM, tin the TSOP-2-44 pads both on PS2 and adapter side, align and solder as any BGA component by hot air station. It's better to use a small piece of capton tape to cover pads at PS2 side in the middle of TSOP-2-44.
PCB stack-up:4 layer, choose 0.6-0.8mm thickness at JLCPCB. Spacing between PS2 MOBO and top RF shield is 2.0mm, so we have 0.2+0.8+1.0mm limit (resistor arrays/PCB/flash). Better to choose 0.6mm (to do that select LeadFreeHASL or ENIG option)
To enable write operations connect circle pad to SWR signal (could be found at 70k SM)
MX29LV320/640 were kept in mind during making.
BOM list:
-x2 0402 100nF caps
-x5 Resistor Arrays concave 0402x4 560R
...
Untested

 

[R3Z3N]

Wording is confusing. So you install it on unpopulated area where a ROM goes...but you have to remove and reinstall?

I assume you just mean desolder the BOOTROM and solder this on once MX29LV320/640 TSOP is flashed? Because on 70k that spot is already populated with the sony BOOTROM

I am curious...besides package, what is the difference between this and Tschicki's bootrom flex? This doesnt have AND gates I see...

I wouldnt mind ordereing some, already have 5 of Tschicki's flex to try. Looking also to add other drivers like mmce, hdd, etc for my crystal chip modchip fun. IE I already have the crystal chip booting BootManager (its interface/scripting interpreter) from hdd, mmce and usb but those drivers need to be on memcard, so having in rom would be nice.

 

[Armorant]

Wording is confusing. So you install it on unpopulated area where a ROM goes...but you have to remove and reinstall?

I assume you just mean desolder the BOOTROM and solder this on once MX29LV320/640 TSOP is flashed? Because on 70k that spot is already populated with the sony BOOTROM

I am curious...besides package, what is the difference between this and Tschicki's bootrom flex? This doesnt have AND gates I see...

I wouldnt mind ordereing some, already have 5 of Tschicki's flex to try. Looking also to add other drivers like mmce, hdd, etc for my crystal chip modchip fun. IE I already have the crystal chip booting BootManager (its interface/scripting interpreter) from hdd, mmce and usb but those drivers need to be on memcard, so having in rom would be nice.

GH-032/035: TSOP-2-50 (combined BOOTROM) is installed and to the right of it you might see a half of TSOP-2-44 footprint. There is exactly the same at the bottom as well. My goal is to use 2 separate flashes, the Tschicki aims to replace that unified TSOP-2-50 BOOTROM which is harder, but also that is the only solutin for 79k-90k IIRC

 

[adamhun94]

Excuse me in advance if I ask anything stupid, I'm totally new to flashing custom ROMs.

I just got two 70k consoles (one GH-032, second is unopened yet) to resurrect their IDE port and this thread got me thinking on modifying the original ROM to add HDD drivers to boot directly from a drive.

Anyway, I think I will fabricate Armorant's PCBs, but I have a question:
How did you initially flash the memory chip? I don't have any expensive programmers, is it possible to use anything DIY here?
If I understand correctly with the SWR pin connected, later it can be reprogrammed using a software directly from the console, but I have to get there somehow.