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Eboot Loader의 개발자인 Fanjita 씨와의 일문일답
Q: 현재 진행 중인 작업에 대해 한 말씀 부탁드립니다.
A: 지금 하고 있는 작업은 GTA 의 취약점을 이용한 2.01/2.5 Eboot 로더 개발입니다.
게임월드님의 말처럼 크리스마스 때 PSP유저를 위한 대박선물로 드리기 위해 열심히 작업하고 있습니다.
그런데 시간이 부족하네요.
GTA 의 취약점을 이용하여 2.5 다운그레이더도 시도 해보았지만 실패하였습니다.
펌웨어 2.6 같은 경우는 보안이 더욱 강해져서 현재 상황에서는 로더를 개발하기 어려울 것 같습니다.
인터뷰 원문
1) Could you tell us about yourself? Where you work, go to school and where you live etc..?
I'm 32 years old, I live and work in Edinburgh, Scotland, for a medium-sized software company. Married with a very understanding wife :) and 2 dogs.
2) When did you first get into computers and coding?
I started coding at the age of about 10, with a Sinclair ZX81 that my parents bought us for Christmas. In those days you pretty much had to type in your own games, and I quickly got hooked on modifying those games and making my own.
Technology back then was pretty primitive, and you pretty much had to use assembler to get decent performance. Ah, fond memories of hand-assembling code and entering it in a hex loader...
3) What made you get into the Psp Homebrew scene?
When I first heard about the PSP (just after the European launch on Sept 1st 2005), I wasn't all that interested. I have a decent MP3 player already, I don't get many opportunities to watch videos on the move, and I find most console games a bit lacking in depth.
But then I heard that it was capable of homebrew, and it seemed like a pretty cool platform to work with - decent power, wifi and IR capability, etc. I bought one not long after that, and after playing some UMDs for a few days, got bored and started hacking...
I saw the exciting stuff that was happening at the time with the v2.0 TIFF exploit, and wrote my first homebrew (TIFF Tetris) as a way of learning about the system. From there on in, I picked up some early work on EBOOT loading that was being done by Saotome, and started developing it in earnest.
4) Hello World for Gta is a firmware exploit via the gamesave function for GTA. You have demonstrated the execution of a simple application that was coded into a GTA gamesave slot and accessed via the GTA "load game" option. Tell the viewers of Pspemulation.com how you figured this out?
I can't take all the credit, the hard work was actually done by other people. Edison Carter famously first exploited GTA, releasing his Cheat Device for GTA. It was obvious that he had found a way to run code via the savegame, and I started chatting to him about it. Edison was reluctant to release his code, though, because he was worried about the legal position of having reverse-engineered the new PSP encryption that was being used on v2.0 games.
Not long after, Jim Paris and psp123 succeeded in independently reproducing Edison's work (I guess they were inspired by the fact it had been proven to be possible). I kept in touch with them as they worked on it, and once they released their tools for working with encrypted savegames, I was able to examine Edison's code and work with that to produce a loader that could load binary files (like the Hello World program).
At the moment, I'm working on developing that exploit so that it can run the EBOOT loader, which should allow us to run just as much homebrew on v2.01 and v2.5 as we can now on v2.0.
5) Do you think its possible to make a ISO loader using the expolit to run on 2.0 or higher?
I think it may be theoretically possible to run ISOs on v2.0. v2.01+ seems less likely, because the environment is a lot more restricted.
However, I'm no fan of piracy, and so I'm in no rush to develop an ISO loader. Although there are legitimate uses for one, the majority of people seem to just want to use a loader to pirate games. Considering that the piracy issue is why Sony try so hard to block homebrew, you can understand why I don't want to encourage it .... :)
6) We know thats its impossibe to access KERNEL mode in 2.0 thats the problem since sony patched it . Are you working on a way to access Kernel mode in 2.0
Personally, no. I know of one or two people who are tinkering with it, but it's a pretty big job. At the moment, I think we can achieve most of what we want to do from within the non-kernel environment.
7) How often do you spend time coding on the PSP?
I do at least a little bit of coding most nights, in between working and normal life :) When the GTA exploit tools first hit the streets, I coded for almost 24 hours straight, trying to get a downgrader to work...
8) What problems have you had to overcome and how much have you learned while coding for the Psp.
I have a pretty strong background in programming, so I understood most of the principles without much difficulty. There are two main difficulties with the PSP, especially on v2.0 :
- It's very difficult to debug programs when they don't work - typically, the PSP just turns itself off! Fortunately I've spent most of my career debugging hard problems in customer environments, so I've got a pretty good kit-bag of debugging techniques :)
- We're all learning about the PSP as we go along, so there's a shortage of reference material. Most of the time, it's painstaking experimentation to work out how any given feature is supposed to work.
I've learnt quite a lot in the process - this is the first time I've worked with the PSP's MIPS processor, and I've got practical experience of lots of aspects of operating systems and programming in general, that I'd mostly only encountered theoretically before. I'm a great believer that software is generally pretty easy to learn once you've got a basic theoretical grounding - most systems follow the same rules and general principles, and you can learn a new system or environment within a week or two.
9) Theres lots of people interested in developing for the Psp what words of wisdom can you offer them in there quest?
The first step is to learn the basics of programming. The PSP is no place to start - it's hard to work with, and the tools and information available are generally aimed at experienced programmers. The best place to start is the PC - get a simple Windows C compiler, and follow a simple web tutorial to understand the principles. Once you're comfortable on the PC, you're ready to move to the PSP.
The ps2dev.org website is by far the best hangout for advanced PSP developers, and it's where I learnt pretty much everything I know. For less-experienced programmers, the developers' forums at somewhere like pspupdates.qj.net are an active, friendly place to get help and advice.
10) How far can we push the Psp using techniques we know now and maybe new ones we will learn in the future ?
We're still only just starting to exploit the power of the PSP's graphics and media capabilities. These are the areas I'd expect to see continue to improve as time goes by.
Wifi is also an up-and-coming technology. The tools to make use of wifi have only recently become widely available to homebrewers, so I hope we'll see lots more innovative use of the network.
11) Whats your favourite Emulator/Homebrew release for the Psp and Why?
That's hard, there are lots and lots of good programs out there. In terms of emulators, the SNES9x TYL emulator probably has the best balance of performance, available games and technology level - the SNES games were developed at a time when the hardware was capable of decent presentation, and Nintendo have always been strong on good gameplay on their consoles.
In homebrew, there are far too many to choose from. Attack Of The Mutants is probably the most well-rounded game, nicely presented and addictive. For utilities, I've found PSPInside absolutely invaluable for PSP hacking. For technical achievement - that's a toss-up between Moppi's Flower Demo, and Throttle-X.
12) Your thoughts on the Psp Emulation/Development Scene and how can it be improved?
The biggest issue for the PSP scene is the glory-seeking. There are plenty of people who spend a lot of time arguing over who did what, and who's the best. It's unproductive, and divisive. It would be much nicer to bring back some of the early days of the PSP development scene, where there was a huge collaborative spirit - lots of people bringing their expertise to bear on a huge, difficult problem.
I always try to make sure that people receive appropriate credit for anything that's gone into my work. I'm not out for fame or attention, I just want the fun of solving hard problems, and the satisfaction of bringing the PSP's full potential to the masses.
13) What are your thoughts on Datels 4gb Harddrive compared to Sony and Sanyos 1-2gb memory sticks,What do you use? What tools do you use?
The hard-drive is a neat idea, and anything that brings cheaper storage can only be a good thing - memory sticks are one of the most expensive forms of flash memory available. I don't own a Datel hard-drive yet, at the moment I make do with 2 1GB sticks - which is just about enough, because I don't have a large ROM collection, I don't own any ISOs, and I don't usually use my PSPs for music or video :)
I have 2 PSPs, one is a white v1.5, the other is a black v2.0. Those have so far been enough to do most of what I wanted to do, but I'm feeling a bit limited now that the v2.5 / v2.6 scene has started opening up, and ideally could use 2 more.
14) What are you currently working on.Anything you care to mention or hint to?
Right now it's all about fully-exploiting the GTA exploit, so that proper homebrew can be brought to the v2.01 and v2.5 users. As you say, I'm hoping to be able to release that as a little Xmas gift, but time is getting a little short now :)
I tried a downgrader, but had to give up because it doesn't seem possible with this exploit.
v2.6 will also be difficult, because the security is getting tighter and tighter, and extracting the info we need to use 2.6 properly is currently very hard.
15) To end this interview do you have anything you'd like to say to your fans?
You know, I'm actually a little uncomfortable with the 'Cult of Fanjita' that seems to have arisen, especially as there are many other, more talented developers out there who don't get nearly enough recognition. Life was a lot easier when I was unknown, and could get on with hacking in peace! But I am thankful for the appreciation, and being well-known in the scene means that I do get to hear about a lot of the interesting stuff that's going on.
Finally, I'd just like to encourage people who want to show some appreciation, to visit my website ( http://www.fanjita.org/psp.html) occasionally to click on the ads there. It doesn't cost you anything, but every click goes towards helping to fund future development work.
And keep an eye out, there's plenty more good stuff still to come!
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