blackrhino is linux, so there's no need to get it to 'have linux starting from blackrhino' as you said, BUT, there's a procedure to get a gui running on blackrhino.
You need to be able to access blackrhino from a computer you have online and use the computer to download a gui and transfer it to the ps2. Then you need to install it, and then you can boot it. That's what you have to do in a nutshell, i'm not sure of the details.
Ver. 3 NTSC independence exploited ps2, 120 gig WD HDD, HDLoader .8c, Ulaunchelf 4.04, Blackrhino linux on WD 40 gig HDD