This sandbox is where I will describe the process of properly installing Gentoo on a PS3.
Since firmware 3.21, it is not possible to install OtherOS on official firmware. In order to do this, modified firmware has to be installed. Consoles with firmware 3.55 and older can install modified firmware without difficulties. Those who were unfortunate enough to install 3.56 or newer have to wiretap the console's flash storage and upload the modified firmware. Consoles that come out from the factory with 3.56 or newer may never grace OtherOS.
OtherOS++ and REBUG are a few modified firmwares that enable OtherOS.
Consoles with modified firmware will need a kernel with Geoffrey Levand's patches in order to make use of the firmware's HDD regions. These patches also enable a host of features that are normally not available, like LV1 calls, LV1 debug messages over ethernet broadcasts, firmware recognition, improved flash storage access and many more.
u32 or u64?
There is currently no multilib support for PowerPC in Gentoo. Due to this, users have to choose if their PS3 will run a 32bit or 64bit userland. The former will enable running of some proprietary programs like Opera, but the latter is required to run IBM lx86 and correctly configure Xorg.
|ps3||enables ps3 features in a handful of packages|
|altivec||enables AltiVec code generation, speeds up multimedia tasks|
|-ibm||applies only to G5 and pSeries|