[Defy General] sadasas:
Q1: What is a custom ROM? What to can it do to my phone?

A1: A custom ROM can be either:

- Modifications to the official company ROMs (a.k.a Stock ROMs) , which increases its speed and stability compared to original Stock ROMs .

Q 2.1: What's Recovery Mode? What is Download Mode? What are the different "Modes" that my phone can go into?

A2: Recovery Mode is a place where you go to if your phone is ever "stuck" or in a "bootloop" if you installed a ROM wrongly .

The stock recovery mode can't do much and therefore if you want better advantages such as:

-Backing up your current ROM and data

-Fixing Force Close Permissions

-Wiping your Dalvik-Cache

-Wiping Battery Stats (if your battery meter is jumpy , like all custom Stock ROMs)

-Install unsigned .zip files

-Formatting various parts of your internal memory (/system , /data etc)

-Mount USB Storage in Recovery Mode

The only thing you can do is use CLOCKWORKMOD RECOVERY

For Download Mode , it is a Samsung-exclusive feature that allows you to "Download" custom stock ROM files into your phone .

It works like a normal install in ClockWorkMod Recovery (a.k.a CWM) , except that it automates everything (wiping data , wiping system stuff)

These are possible modes which you can use to enter different places (for advanced people only):

Home + Power = Recovery Mode (whether stock or CWM)

Home + Volume Down + Power = Download Mode (normal)

Home + Volume Up + Power = ARMv9 Dump Mode

Home + Volume Down + Volume Up + Power = Download Mode (EMERGENCY)

Q2.2: What is ClockworkMod Recovery? How do I use it?

A2.2: ClockworkMod Recovery is one of the best custom recoveries out there and was made by the AWESOME koush

Here's how you use it by devilcode:

Originally Posted by devilcode

There you go.... not from v4.0.0.9 but its of a old version but will give you and idea or to anyone else .. will not post a link to some other site so just posting the explaination here

Options explained

1.reboot system now

This one is self-explanatory.

2.apply update from sdcard

This can be used for installation of any official or unofficial update, ROM, kernel, theme etc. that is in a zip format installable from recovery, as long as the file is named update.zip and it has been placed on the root of your SD card (i.e. not in any sub-folder). Selecting this option (and most of the options featured below) will bring up a rather annoying confirmation prompt but this has saved us on multiple occasions from a lot of trouble we would have been into due to accidental key presses.

3.wipe data/factory reset

This option wipes all user data on the device as well as cache. Doing this will leave your phone in the state it was in when you bought it or when any custom ROM was first installed. It will also wipe any sd-ext partition that you might have setup

4.wipe cache partition

Wipes the cache partition of the device to clear all the data accumulated there over use. This is often used before installing a new ROM, app, kernel or any similar mod via recovery.

5. install zip from sdcard

This option brings up the following sub-menu:

A. apply /sdcard/update.zip

This one is essentially the same as the ‘apply update from sdcard’ option of the main menu.

B. choose zip from sdcard

Lets you install any zip file (with any name) from any location on your SD card. The file can be for a ROM, a kernel, an application, a theme or any mod as long as it is in recovery-flashable zip format. This is the most widely used option for installing a ROM that you have downloaded and copied to your SD card. Entering this option will bring up a screen that will allow you to browse your SD card for the zip file and select it for installation

C.toggle signature verification

Turns the signature verification on and off. When signature verification is on, you will not be able to install any custom ROMs that haven’t been signed by the developers (most custom ROMs aren’t signed). Switching it off skips the signature verification check and proceeds with the installation.

D. toggle script asserts

Seldom-used option for a vast majority of users. It simply turns script asserts on or off. If you don’t know about these (i don’t), it’s best not to change this option.

E. +++++Go Back+++++

Takes you back to the main recovery menu, obviously!

6.backup and restore

Undoubtedly one of the most important features provided by a custom recovery, the backup and restore feature – also known as Nandroid backup – allows you to take a snapshot of your phone’s entire internal memory including all partitions, and save it on the SD card.

A.Backup

Takes a Nandroid backup, as explained above.

B.Restore

Lets you restore a previously taken backup. Entering this option presents you with a list of existing backups from the SD card that you can choose from for restoration.

C.Advanced Restore

This option is similar to the Restore option but once a backup has been selected to be restored, this option allows you to choose what parts of it to restore. You can choose to restore the boot, system, data, cache and sd-ext partitions

7.mounts and storage

Allows you to perform maintenance tasks on all the internal and external partitions of your android device

A. mount/unmount /system, /data, /cache, /sdcard or /sd-ext

These options let you toggle between mounting or unmounting these respective partitions. Most users don’t need to change these options.

B.format boot, system, data, cache, sdcard or sd-ext

These let you directly format any of these partitions. Take extreme care with this option as formatting any of these partitions will result in losing all data on them, especially the boot and system partitions. Formatting the system partition will remove your ROM and leave your phone without an operating system while wiping the boot partition may brick your phone unless you restore or flash another one before rebooting your device. To learn more about the contents of all these partitions, see our guide to Android partitions.

C.mount USB storage

Lets you enable USB mass storage mode for your SD card right from recovery so that you can connect it to your computer via USB and transfer any files to/from it without having to leave recovery.

8.advanced

This section contains a few options most users will not require, though these can come handy quite often, especially wiping Dalvik cache, which is required before most ROM installations. Here are the options from this section:

A.Reboot Recovery

Lets you directly and very conveniently reboot from recovery right back into recovery. This is useful option for certain back-to-back installations that require the device to at least boot once between them.

B.Wipe Dalvik Cache

Allows you to wipe the cache for the Dalvik virtual machine (the custom-built Java virtual machine for Android).This is required before most ROM installations and at other occasions too, for fixing some problems.

C.Wipe Battery Stats

Wipes the saved battery usage statistics and effectively recalibrates the battery. Useful in various scenarios when Android isn’t showing correct battery levels.

D.Report Error

In case of errors, this feature can be used to save a log of recent ClockworkMod recovery operations on the SD card that you can later report from Android using ROM Manager.

E.Key Test

Lets you press any of the hardware keys to see if they are properly functioning, and to see their key codes.

F.Partition SD Card

This option gives you a no-frills way to partition your SD card properly for use with ROMs that support data2ext (a very handy hack for low internal memory devices that enables an /sd-ext partition on the SD card to be used as the internal user data storage i.e. as the /data partition). Once this option is selected, you will be given options to choose the sizes for the /sd-ext partition as well as an optional /swap partition on the SD card, and will then automatically format it for you, leaving the remaining space for normal SD card usage. This option will wipe all data from your SD card so use it with caution!

G.Fix Permissions

Fixes the file permissions for the internal memory partitions back to default. This is very useful as a fix for several errors and Force-Closes that start appearing after you or an application you installed and provided root access end up messing up the permissions of important files.

Hope it helps :d

Q3: Help me, my phone is in a bootloop and won't go into the Launcher!

A3: Firstly , define your bootloop:

If you are stuck at the "Motorolla" logo , that means you did not make a factory reset and cache wipe from Recovery Mode . Do that , then reflash and try again .

However , if your phone is stuck at the bootanimation:

Stuck for more than 10mins and is repeating the animation: You did not flash your ROM properly . Refer to above .

Stuck for less than 10mins and is NOT repeating: I suggest you have some patience :D