so if I root, hows that manifest?

[endotherm]

I'm new to the whole mobile thing, so I've been looking around but I've been having some trouble determining exactly how rooting manifests to the user. I've seen references to 'su' in the tutorials which leads me to believe that the process enables a root account, but I see no reference to setting a password.

So my question is, is it possible to control tightly what apps get root and what can't? can I prevent malware and bad apps from abusing this privlege, whilst granting me and knowngood apps root happiness? is there an interactive sudo\gksu\kdesu kinda layer for invoking root, or is it more like editing your sudoers?

[S.Prime]

Without actually seeing the references to "su", let me offer that su is usually the abbreviation for the Superuser App. Rooting does give r/w permission to the system area, but the Superuser App controls which apps can write to the system area and as each app is installed that needs root access, you will be prompted by the Superuser App to grant or deny that access.

[endotherm]

ok, that answers many questions. I had assumed 'su' was a reference to the *nix Switch User command (which is sometimes incorrectly called 'superuser', because its most commonly used to switch to the root user's shell). this SuperUser app sounds more like sudo or UAC.
 
so, does SuperUser ask the user for permissions when a restricted action is requested, or do you have to instruct the app to run as root?

[JayJ]

When a root application requests root access a Superuser toast will pop up asking whether you wish to grant or deny access, this will give the said application perminant  root access.

The is also another version called SuperSU, this is similar in function just from another developer. When I rooted my N7 I used Root Toolkit by WugFresh and SuperSU is the app of choice here.

EDIT- SU (Switch User) Binary is contained within the Superuser/SuperSU applications.

[S.Prime]

The su app grants the application access with all of the permissions that the application requests. Therefore when you install an application and grant it su access, you are agreeing to all of its permission requests. I prefer to use only applications requesting su privileges that have been tried and tested by the Android community.

[JayJ]

The SuperSU application is developed by Chainfire, a recognized developer on XDA and the developer of several important apps such as Stickmount, Mobile Odin and Chainfire 3D.

[endotherm]

Thanks guys, thats really helpful.

I'll admit, much of why I am interested in rooting my tablet is to constrain some of the more outrageous permissions required by some apps, block ads, etc.

From what you have said and what I've heard about unlocking, the protections on the system partition are largely based on mount options. are there more granular filesystem permissions that can be applied (chown/chmod)? how much control can we exercise over the filesystem, users, groups, service accounts, etc?

[S.Prime]

My knowledge of Linux is limited, so I cannot comment on modifying system level permissions, but from what I have learned, we have a limited set of Linux commands on our tablet and that during the root process we add BusyBox which extends the Linux command set. You may have to look at the developement level to find the answers to your questions.This is the discription of BusyBox from Google Play:

BusyBox is a software application that provides many standard Unix tools, much like the larger (but more capable) GNU Core Utilities. BusyBox is designed to be a small executable for use with the Linux kernel, which makes it ideal for use with embedded devices. It has been self-dubbed "The Swiss Army Knife of Embedded Linux".

[endotherm]

wonderful, thanks!

I'm certainly getting the impression that this is a rather different beast than the linux I am used to.

so one last question: can you please review these definitions/assertions, and tell me if I am wrong somewhere?

1) flashing: the process of replacing the rom (os) of the device. does not affect userspace storage.

2) unlocking: the process of reconfiguring mount attrib for the system partition to RW mode.

3) rooting: the installation of tools to control access to systemspace resources (files on /)

4) custom recovery: utilies for backing up the rom to the device or remote storage, and for restoring from the backups at boot time.

5) unlocking bootloader: needed to change to new flavor of rom, but not needed to run rooted stock version. once unlocked, may not be able to be relocked effectively, because of hardware switch.

6) fastboot: a bios like startup menu from which you could access custom recovery utils.

7) factory reset does not live on the device, so an initial stock backup is required if you ever want to go back to stock.

that sound about right? I'm suprised at how much there is to learn on this topic, and I'll feel much better once I have the knowledge and confort to always be able to bring my device back to stock, no matter how I abuse it.

Thanks again