[Multiboot] [Update 1/7/11] Create, manage and boot your ROM options via CWM!

Introduction

This thread describes an experimental mod that allows you to boot into other boot images stored in your sdcard.
The N1 does not have enough internal memory to store more than one android image, thus we have to use the sdcard for this.


NOTE:

This mod is experimental, and for advanced users only


Requirements (READ THEM CAREFULLY):

- A rooted and unlocked phone
- A FAST enough sdcard. This mod will work with any sdcard but I'd suggest at least a Class 4 card for performance reasons
- Your sdcard should have enough free space. Each 'boot option' that you create reserves 400MB of space in your sdcard
- In order to create a new boot option, you need a flashable zip over CWM of the ROM you wish to boot to. The flashable zip of the ROM is the same that is used for usual ROM installation. Also the zip should be using the latest update-binary format as is scripted in updater-script (e.g. the mount command takes 4 args, etc.)


Advanced Information regarding the process

- The mod requires a boot.img that is flashed by the zip. This is used for extracting the ramdisk, commenting out the mount mtd commands and using this ramdisk for chrooting into the ROM environment
- If no boot.img is existing, the ramdisk is picked up from /sdcard/ramdisk/
- The kernel used for booting all boot options is the one installed in the phone's boot mtd. This means that you need the respective kernel modules (e.g. WiFi) for this kernel, not the one that is bundled in the ROM that is multibooted. For example, if your main ROM is CM, pick the kernel modules from this one and push them to the multibooted ROM's /system/lib/modules/


Multiboot mod Installation

Download: N1_CWM-4.0.0.5-nobodyAtall-r2.img

Install via fastboot
Install via adb


Multiboot ROM Installation

- Boot into the recovery and navigate to the new 'multiboot' menu. There you'll see the following options:

• Boot into selected option!
• Select default boot option
• Unset default boot option
• Create boot option from zip
• Delete existing boot option
• Flash zip to boot option

- Select multiboot->Create boot option from zip and then pick the flashable ROM zip. Be patient, this step reserves the space and flashes the selected zip to the system.img in the sdcard
- If you need to flash additional zips for this ROM, Select multiboot->Flash zip to boot option, pick your newly created boot option and then pick the zip you need to flash.
- Select multiboot->Select default boot option and pick your newly created boot option
- Select multiboot-> Boot into selected option! (first boot will take some time depending on your sdcard speed).
To verify you have booted to your newly created boot option, check 'adb shell mount', it should say that /system /data and /cache is mounted from /loop* devices and not from mtd*




ROMS verified to multiboot

Well, any ROM should be able to multiboot provided the requirements stated above are covered. The following ones have been verified to work:

[ROM] CyanogenMod-7.1 for Nexus One

[ROM] NEXUS N1 Passion MIUI.us Presents MIUI Pure English [AOSP]

CM 7 ExtremeMod ROM by Ken Mood


Uninstall

- Normal reboots will boot from the phone's mtd partitions.
- This mod makes no changes to your phone's mtd partitions. Flashing a new recovery will uninstall the old one obviously.
- To remove installed boot options, navigate to multiboot->Delete existing boot option and pick you choice. Alternatively remove the boot option you want from /sdcard/clockworkmod/multiboot/

Changelog:

(1/7/11) N1_CWM-4.0.0.5-nobodyAtall-r2.img
Fixed bug that flashed the multiboot ROM kernel in the phones kernel partition
Improved error reporting

(30/6/11) N1_CWM-4.0.0.5-nobodyAtall-r1.img
First version of CWM recovery providing the multiboot options

method77 said:

Nice one. Can we use CM nightlies that came after the RC?

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You can use it with any CM7 ROM

Hello shorza,

To be honest, I've only been testing the multiboot part.
However, I think that backup works fine here:



Also the backup folder is created correctly:

~ # ls -la /sdcard/clockworkmod/backup/2011-07-01.06.49.58
drwxrwxrwx 2 root root 4096 Jul 1 06:52 .
drwxrwxrwx 5 root root 4096 Jul 1 06:49 ..
-rwxrwxrwx 1 root root 93489792 Jul 1 06:52 .android_secure.img
-rwxrwxrwx 1 root root 3670016 Jul 1 06:50 boot.img
-rwxrwxrwx 1 root root 37359168 Jul 1 06:52 cache.img
-rwxrwxrwx 1 root root 184136832 Jul 1 06:51 data.img
-rwxrwxrwx 1 root root 222 Jul 1 06:53 nandroid.md5
-rwxrwxrwx 1 root root 4194304 Jul 1 06:50 recovery.img
-rwxrwxrwx 1 root root 146908608 Jul 1 06:50 system.img

On another note, I'll be doing an update today to fix some bugs related to multiboot.

shorza said:

Maybe my sdcard is too slow.

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You need to be patient. It takes a long time to boot (especially for the first boot) and if the recovery seems frozen, this is a good sign - it means it's booting.

Posted -r2.

This fixes a bug that would flash the multiboot ROM's kernel to the phone's kernel partition. Also improves logging in case of errors.

This is because the ROM is run using the device's kernel and not the one that comes with the ROM as stated in the first post.
To make wifi work, simply copy your wifi kernel module from /system/lib/modules to this same did within the multibooted ROM.

Ellises said:

So wifi doesn't work in the latest version of miui.us when using it as a multiboot option. such says in logcat "Failed to load Wi-Fi driver." it works when the rom is installed as normally so it must be the kernel from this application. but wifi on cyanogenmod works so that is good.

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Sent from my Nexus One using XDA App