MultiROM v32 - unofficial port

[Steel01]

Introduction

MultiROM is one-of-a-kind multi-boot mod. It can boot any Android ROM as well as other systems like Ubuntu Touch, once they are ported to that device. Besides booting from device's internal memory, MultiROM can boot from USB drive connected to the device via OTG cable. The main part of MultiROM is a boot manager, which appears every time your device starts and lets you choose ROM to boot. You can see how it looks on the left image below and in gallery. ROMs are installed and managed via modified TWRP recovery. You can use standard ZIP files to install secondary Android ROMs and MultiROM even has its own installer system, which can be used to ship other Linux-based systems.

Features:
* Multiboot any number of Android ROMs
* Restore nandroid backup as secondary ROM
* Boot from USB drive attached via OTG cable

You can also watch a video which shows it in action.​

Warning!

It _is_ dangerous. This whole thing is basically one giant hack - none of these systems are made with multibooting in mind. It is no longer messing with data partition or boot sector, but it is possible that something goes wrong and you will have to flash factory images again. Make backups. Always.​

Installation

Manual installation
Firstly, there are videos on youtube. If you want, just search for "MultiROM installation" on youtube and watch those, big thanks to all who made them. There is also an awesome article on Linux Journal.

MultiROM has 3 parts you need to install:

• MultiROM (multirom-YYYYMMDD-vXX-shieldtablet.zip) - download the ZIP file from second post and flash it in recovery.
• Modified recovery (twrp-multirom-YYYYMMDD-UNOFFICIAL-shieldtablet.img) - download the IMG file from second post and use fastboot or Flashify app to flash it.
• Patched kernel - You can use either one of the stock ones in second post or third-party kernels which include the patch, you can see list in the second post. Download the image and flash it through fastboot or Flashify.

You current rom will not be erased by the installation.
Download links are in the second post.​

Adding ROMs

1. Android
Go to recovery, select Advanced -> MultiROM -> Add ROM. Select the ROM's zip file and confirm.​

2. Ubuntu Touch
Not yet ported.​

3. Firefox OS
Not yet ported, but should be as easy as other Android ports.​

Using USB drive

During installation, recovery lets you select install location. Plug in the USB drive, wait a while and press "refresh" so that it shows partitions on the USB drive. You just select the location (extX, NTFS and FAT32 partitions are supported) and proceed with the installation.
If you wanna use other than default FAT32 partition, just format it in PC. If you don't know how/don't know where to find out how, you probably should not try installing MultiROM.
If you are installing to NTFS or FAT32 partition, recovery asks you to set image size for all the partitions - this cannot be easilly changed afterward, so choose carefully. FAT32 is limited to maximum of 4095MB per image - it is limitation of the filesystem, I can do nothing about that.
Installation to USB drives takes a bit longer, because the flash drive is (usually) slower and it needs to create the images, so installation of Ubuntu to 4Gb image on my pretty fast USB drive takes about 20 minutes.
Enumerating USB drive can take a while in MultiROM menu, so when you press the "USB" button in MultiROM, wait a while (max. 30-45s) until it searches the USB drive. It does it by itself, no need to press something, just wait.​

Updating/changing ROMs

1. Primary ROM (Internal)

• Flash ROM's ZIP file as usual, do factory reset if needed (it won't erase secondary ROMs)
• Go to Advanced -> MultiROM in recovery and do Inject curr. boot sector.

2. Secondary Android ROMs
If you want to change the ROM, delete it and add new one. To update ROM, follow these steps:

• Go to Advanced -> MultiROM -> List ROMs and select the ROM you want to update.
• Select "Flash ZIP" and flash ROM's ZIP file.

Source code

MultiROM - https://github.com/CM-Shield/multirom (branch flipped-screen)
Modified TWRP - https://github.com/Tasssadar/Team-Win-Recovery-Project (branch master)
Device Tree - https://github.com/CM-Shield/android_device_nvidia_shieldtablet (branch cm-12.0-unified-mrom)
Kernel w/ kexec-hardboot patch - https://github.com/CM-Shield/android_kernel_nvidia_shieldtablet (branch cm-12.0-mrom)​

 

[Steel01]

Downloads

1. Main downloads

MultiROM: multirom-20150909-v32a-UNOFFICIAL-shieldtablet.zip
MultiROM Touch Support (only needed if not upgrading): multirom_shieldtablet_touch_support.zip
Modified recovery (based on TWRP 2.8.7.0): twrp-multirom-20150909-UNOFFICIAL-shieldtablet.img

Kernel kexec-hardboot patch (Stock 5.1.1 all variants): kexec_patch_stock_311.zip
Kernel kexec-hardboot patch (Stock 5.1.1 all variants): kexec_patch_stock_31.zip

Kernel w/ kexec-hardboot patch (Stock 5.1.0 wx_na_wf): kexec_boot_stock_na_wf_30.img
Kernel w/ kexec-hardboot patch (Stock 5.1.0 wx_na_do): kexec_boot_stock_na_do_30.img
Kernel w/ kexec-hardboot patch (Stock 5.1.0 wx_un_do): kexec_boot_stock_un_do_30.img

Kernel w/ kexec-hardboot patch (Stock 5.0.1 wx_na_wf): kexec_boot_stock_na_wf.img
Kernel w/ kexec-hardboot patch (Stock 5.0.1 wx_na_do): kexec_boot_stock_na_do.img
Kernel w/ kexec-hardboot patch (Stock 5.0.1 wx_un_do): kexec_boot_stock_un_do.img

MultiROM Manager: MultiROMMgr.apk​

2. third-party kernels with kexec-hardboot patch
BitO-K - http://forum.xda-developers.com/shield-tablet/development/tweaked-kernel-nvidia-shield-tablet-t3069776

Nicely ask your kernel developer to merge kexec-hardboot patch (patch for shieldtablet).​

3. Other downloads

Ubuntu (kernel and packaging by Bogdacutu):

• Download Thread

4. Old downloads by Bogdacutu

• v31/r3
  • Patched TWRP
  • MultiROM Installer
  • Patched Lollipop kernel (for kernel devs, here's the patch: http://hastebin.com/timaneyuwi.diff)
• v31/r2:
  • TWRP
• v30/r1:
  • TWRP
  • MultiROM

 

[PDNKED]

Works in 5.0.1?

 

[Bogdacutu]

Works in 5.0.1?

yes. it won't work on kitkat though, since there's no patched kernel yet (I'll compile one for kitkat too eventually)

 

[PDNKED]

yes. it won't work on kitkat though, since there's no patched kernel yet (I'll compile one for kitkat too eventually)

All done. Now... How i add mrom images? I can't wait for ubuntu touch.[emoji1]

 

[grv00711]

nexus 6

could this work on nexus 6? also would i have to uninstall cwm and use twrp for this with shield tablet 32 lte us version?

 

[berryman13]

Amazing work bogdan.

 

[lowsum]

yes. it won't work on kitkat though, since there's no patched kernel yet (I'll compile one for kitkat too eventually)

But kitkat can be installed as secondary isn't?

 

[notyu1459]

YAAAAYYYYYY!

Time to liberally screw around with some experimental 3rd party ROMs! :laugh:

 

[xanthrax]

But kitkat can be installed as secondary isn't?

I haven't tried but theoretically yes, it should work

sent from my Darkside of SHIELD Tablet

---------- Post added at 10:54 AM ---------- Previous post was at 10:50 AM ----------

could this work on nexus 6? also would i have to uninstall cwm and use twrp for this with shield tablet 32 lte us version?

to flash another recovery isn't required to uninstall the previous one, actually you can't even do it, just flash, it will replace the cwm or whatever you used before

sent from my Darkside of SHIELD Tablet

 

[Nezorflame]

The only downside is that recovery still makes all devices look like they're WiFi only versions, which makes universal kernel installers go dumb and install wrong version of the kernel.
Other than that, great job, much appreciated.

 

[grv00711]

I haven't tried but theoretically yes, it should work

sent from my Darkside of SHIELD Tablet

---------- Post added at 10:54 AM ---------- Previous post was at 10:50 AM ----------


to flash another recovery isn't required to uninstall the previous one, actually you can't even do it, just flash, it will replace the cwm or whatever you used before

sent from my Darkside of SHIELD Tablet

thank you

 

[grv00711]

I haven't tried but theoretically yes, it should work

sent from my Darkside of SHIELD Tablet

---------- Post added at 10:54 AM ---------- Previous post was at 10:50 AM ----------


to flash another recovery isn't required to uninstall the previous one, actually you can't even do it, just flash, it will replace the cwm or whatever you used before

sent from my Darkside of SHIELD Tablet

what are the chances of being able to run windows 8.1 os on the shield tablet us 32 lte?

 

[Bogdacutu]

what are the chances of being able to run windows 8.1 os on the shield tablet us 32 lte?

extremely close to 0. even if it happens, it would still be just the RT version

 

[grv00711]

extremely close to 0. even if it happens, it would still be just the RT version

new to this -sorry for the stupid questions..

 

[ahmad.gh1]

Hey i installed multirom v28 and i have sd gpe and sd sense roms can i flash diff kernels for each one ? Thanks

 

[berryman13]

Windows 8 is never running on our shield tablets. More feasible ideas : Ubuntu, kali, debian, etc.

---------- Post added at 01:44 AM ---------- Previous post was at 01:44 AM ----------

Hey i installed multirom v28 and i have sd gpe and sd sense roms can i flash diff kernels for each one ? Thanks

Not unless they're made for this device

 

[berryman13]

For a proof of concept I will be flashing OTA.1.2.1 side by side with lollipop 2.1, wish me luck!

 

[grv00711]

i wish i had a clue!

 

[lowsum]

For a proof of concept I will be flashing OTA.1.2.1 side by side with lollipop 2.1, wish me luck!

I tried, it didn't work for me, I also tried other roms but didn't found any that booted. I'm used to multi rom on my nexus 7, I don't think it's an error on my part. Wish you luck!