Following the release of the PS3MFW Builder, the efforts to bring back OtherOS onto the PlayStation 3 had been all but abandoned. Now, however, a hacking group has successfully managed to bring back OtherOS to the PS3.

Via the tweet of PS3 hacker Youness Alaoui, the explanation regarding the return of OtherOS comes courtesy of the PS3MFW team:

But today, we have some very good news for you, OtherOS is finally making a comeback to our PS3 systems. The team at gitbrew.org have released a publication announcing OtherOS++, a modified firmware that brings back the OtherOS option allowing you to install Linux back into your PS3, yes, Linux on the PS3 that you own!  They released Modified Firmwares for 3.41, 3.50 and 3.55 (which were apparently created with PS3MFW, the new tasks needed are available on git.gitbrew.org). After installing the modified firmware, you will need to run some tools in GameOS in order to properly install the petitboot bootloader and your Linux installation. OtherOS++ is more than your typical OtherOS since it gives you full access to the machine, no more being tied down by Sony. IF you want to give this a try, make sure you follow the instructions correctly on the OtherOS++ page.

The full list includes:

Features:

• Into HV integrated OtherOS bootloader loader (compatible with OtherOS bootloader on 3.15)
• Support for ps3-utils. You can flash new OtherOS bootloader from Linux e.g.
• Ability to deactivate/activate HDD/VFLASH encryption (e.g. with ps3stor-utils)

• OtherOS bootloader is booted directly from HV, no GameOS is involved.
• Enabled QA mode in Update Manager

• Process of booting OtherOS bootloader loader is very similar to 3.15 method

• Booting Linux from HDD/USB/BD/Network

• Linux with GameOS rights

• Full access to all HV SS services (Dispatcher Manager) from GameOS or Linux

• Full access to all System Manager services

• Ability to create/modify/remove repository nodes in LPAR 1 (e.g. with ps3dm-utils or ps3hvc-utils).

• This ability gives you much power over the whole system because many layers of PS3 use repository nodes to exchange information.

• Downgrading without USB dongle or Service Mode

Notes:
Tested 3.41 and 3.55 on PS3 Slim with Gentoo and Debian Squeeze but should work on PS3 Fat without problems
Bug reports are welcome, send it please to geoffrey.levand@mail.ru

Work in progress:

• Creating OtherOS partitions directly on HDD (not VFLASH)
• FreeBSD support
• Permanently disabling HDD/VFLASH encryption
• Mapping of HTAB with R/W permission
• SYSCON access from LPAR 2

Installing OtherOS bootloader

• Tested ONLY on PS3 models with VFLASH
• During deleting of VFLASH regions GameOS will ask you to reinstall firmware, don’t do it, just press PS3 button and continue
• I use petitboot as OtherOS bootloader. You could use a different one.
• The following order of steps is important
• Delete VFLASH region 6
• Delete VFLASH region 5
• Create VFLASH region 5
• Create VFLASH region 6
• Install OtherOS bootloader on VFLASH with “Install OtherOS”

Booting OtherOS bootloader

• Run “Boot OtherOS”
• Reboot GameOS with “Reboot”

Creating a VFLASH partition for Linux

Notes:

Installing Linux with petitboot

• I used petitboot to install Debian and Gentoo on VFLASH
• I used fdisk to partition ps3vflashh
• Make sure you create a swap partition
• Creating a ready to use Linux distribution images is a work in progress

Booting Linux with petitboot

Notes:

• USB driver in petitboot has problems on PS3 Slim. The problem lies in Linux USB driver.
• Currently i’m trying to fix this problem in Linux kernel