what is the differences between user mode and kernel mode?

[ytmian]

i guess an application can only run in user mode or in kernel mode,witch is desided form the beginning:
PSP_MODULE_INFO("Hello World", 0, 1, 1); //"0" for user mode,while "0x1000" for kernel mode

I knew an application run in kernel mode can do something that can not do in user mode. I think kernel mode is powerful then user mode.

I don't know in what conditions shall I run my application in kernel mode instead of user mode.

[hlide]

i guess an application can only run in user mode or in kernel mode,witch is desided form the beginning:
PSP_MODULE_INFO("Hello World", 0, 1, 1); //"0" for user mode,while "0x1000" for kernel mode

I knew an application run in kernel mode can do something that can not do in user mode. I think kernel mode is powerful then user mode.

I don't know in what conditions shall I run my application in kernel mode instead of user mode.

an app should really run in user mode :

- this is the normal mode for an app
- API in user mode is preserved throughout different versions firmwares so games are still able to run on next firmwares
- no strict hardware dependency

the only reason you need to make a kernel app or rather a kernel module is because you need to access some resources (software or hardware) which aren't provided from user API in order to make an extension to a firmware for instance. The trouble is that you may need to update it as long as a new firmware or a new model appears as some incompatibilities can occur.

[tacoSunday]

This is definitely the sort of thing where if you need to ask that question you should be in user mode.