Does the PSP have an OS running in background?

[methos3]

It's not a specific PSP development specific question, but I believe Sony wouldn't respond that to me.
I've noticed that some games use some tools, like the on-screen keyboard, save data utility, wireless connection interface. There's also the "home" button, that calls the menu for quitting games.
So... does the PSP have an OS in background while the game is running? If not, where do those tools come from? We can call them from homebrews too?

[Criptych]

It's not a specific PSP development specific question, but I believe Sony wouldn't respond that to me.
I've noticed that some games use some tools, like the on-screen keyboard, save data utility, wireless connection interface. There's also the "home" button, that calls the menu for quitting games.
So... does the PSP have an OS in background while the game is running? If not, where do those tools come from? We can call them from homebrews too?

I don't know all the details, being fairly new myself (still hashing out user-mode crap in C, poor me :) but if by OS you mean the kernel, then yes, the basic I/O and interface systems, etc. are always "running" and available to programs. Unlike most OSs, though, the shell - in this case the XMB - is closed when you start a game, though I do believe its state is saved for when the game exits.

[SilverSpring]

All of those things you mentioned are called "Utilities" and yes they are part of the kernel. It was a way for Sony to provide extra functionality for game developers to use. It's also the reason why a huge 8MB of RAM is reserved for the kernel.

There are some samples in the PSPSDK to use these "utilities" for homebrew apps. Look at psputility_xxx.h headers for more information.

Also, the core of the kernel is always running (otherwise how else could the game run?), the thread manager, memory manager, I/O manager, device drivers, etc.

[methos3]

Really? This is really great! And must pretty easy to program, no?

All of those things you mentioned are called "Utilities" and yes they are part of the kernel. It was a way for Sony to provide extra functionality for game developers to use. It's also the reason why a huge 8MB of RAM is reserved for the kernel.

There are some samples in the PSPSDK to use these "utilities" for homebrew apps. Look at psputility_xxx.h headers for more information.

Also, the core of the kernel is always running (otherwise how else could the game run?), the thread manager, memory manager, I/O manager, device drivers, etc.

So... Do the PS2 have a kernel always running too? Isn't the game an OS on the PS2 and some other consoles?
8MB of RAM... And don't those utilities use a huge ammount of CPU too, so that they can be ready to use everytime?

[m0skit0]

Really? This is really great! And must pretty easy to program, no?

Not too hard for simple stuff, but needs some practice. But keep in mind that PSPSDK is an independent SDK. Most likely Sony's SDK is even simpler to program with and have higher level functions.

Unlike most OSs, though, the shell - in this case the XMB - is closed when you start a game, though I do believe its state is saved for when the game exits.

You can think about XMB (VSH to be exact, XMB being the GUI) as another application. The PSP kernel resets to launch a game or launch VSH. So when the PSP starts, kernel launches VSH. When you start a game through VSH, kernel restarts, and loads the game instead of VSH. When you quit the game, the kernel is again restarted and this time loads VSH. Keep in mind that PSP has only 24 MB (+ 32 on 2000/3000/Go models) of user mode memory, so you can't have VSH and a game at the same time on main memory.

[Criptych]

Keep in mind that PSP has only 24 MB (+ 32 on 2000/3000/Go models) of user mode memory, so you can't have VSH and a game at the same time on main memory.

I would love to see (or write... someday) a mod that lets you do that, though - kind of like irShell's multitasking, but instead of multiple apps, bring up VSH in place of the "Do you want to quit the game?" dialog when you hit Home. (If I'm not mistaken, I think the PS2 does.) Maybe have the XMB show up over the in-game screen, like it does with the web browser. Any thoughts on whether that's even possible? The 2000+ has enough memory, but certainly there are other things to be concerned about, too.

[methos3]

Keep in mind that PSP has only 24 MB (+ 32 on 2000/3000/Go models) of user mode memory, so you can't have VSH and a game at the same time on main memory.

I would love to see (or write... someday) a mod that lets you do that, though - kind of like irShell's multitasking, but instead of multiple apps, bring up VSH in place of the "Do you want to quit the game?" dialog when you hit Home. (If I'm not mistaken, I think the PS2 does.) Maybe have the XMB show up over the in-game screen, like it does with the web browser. Any thoughts on whether that's even possible? The 2000+ has enough memory, but certainly there are other things to be concerned about, too.

Well, I don't think it's possible without affecting the games performance.
Didn't you mean the PS3? Because I believe the PS2 doesn't have even a kernel running in betoween the games and hardware. On the PS2, the game is the operating system (I believe so).
Maybe the PS3 can open the XMB while running a game because it's powerful enough (CPU and memory).
But I would love to see the XMB during a game on the PSP, of course :/

[Criptych]

Sorry, yes, I meant PS3 (though I'd be surprised if the PS2 didn't have something in the background, even the GBA has BIOS utility functions). I don't think it would affect performance much, since it would only be active when Home is pressed, and ideally it would suspend the game when it comes up, so that the game won't slow down the XMB either. This is all assuming it's possible in the first place, mind you. :)

[crazyc]

So... Do the PS2 have a kernel always running too? Isn't the game an OS on the PS2 and some other consoles?

The PS2 (and the wii interestingly) has no OS on the main CPU but has an modular embedded OS with a bundle of device drivers running on a secondary CPU. The IOP also doubles as the PS1 CPU.

[methos3]

So... Do the PS2 have a kernel always running too? Isn't the game an OS on the PS2 and some other consoles?

The PS2 (and the wii interestingly) has no OS on the main CPU but has an modular embedded OS with a bundle of device drivers running on a secondary CPU. The IOP also doubles as the PS1 CPU.

Hmm. So does wii have a secondary CPU too?
Yes, I know about PS2's IOP. It runs the I/O modules (irx, that are executable files too).
I believe most consoles don't have an OS running, just like: DS, PSOne, Nintendo DS, etc. Or am I wrong?

[anisebal]

Hello everyone,
If you want to know all things about the PS2 and want to learn something to make coding then please see the playstation2-linux site.
Here you can see the main thing that if you are beginner then this will definitely help you to understand that
"PS2 has an OS or NOT"
If you have any doubt then this site also gives you the solution regarding that.

[m0skit0]

This what I call SPAM, plain and simple.

[Blade]

SPAM!!!! i dislike it........ i would come to believe all modern consoles such as NDS, PSP, PS2 etc. would have an OS... just like windows, they have some sort of multimedia or application access interface, for example: the PSP and PS3 has the XMB, which is used to access system settings, apps, and multimedia... no?

[Raphael]

SPAM!!!! i dislike it........ i would come to believe all modern consoles such as NDS, PSP, PS2 etc. would have an OS... just like windows, they have some sort of multimedia or application access interface, for example: the PSP and PS3 has the XMB, which is used to access system settings, apps, and multimedia... no?

XMB != OS on PSP/PS3

It's basically just a GUI multifunctional utility application and game/app loader interface. The real OS is the kernel that runs in the background, responsible for launching the apps, accessing the hardware, etc.

[m0skit0]

I just hope it's not like Windows xDDD