[How To] Dual-Boot via Lenovo A2109

[vampirefo.]

@vampirefo

...this is clearly cool stuff

I would like to dual boot (own adapted) stock A2110 with (own built) CM-10.2

I see you copy to LNX for switching between tablet and SD situation.

May I ask: what is the magic to make boot believe /system and /data are relocated?

Thanks

The scripts just use cat to flash the boot.img from each OS one wants to boot.

For the OS on sdcard modify the boot.img to point to sdcard rather than tablet.

below is an example script, you can change it to suit your needs.

#!/system/bin/sh

if busybox test ! -f /mnt/sdcard2/dual_boot/custom_boot.img; then
	echo no /mnt/sdcard2/dual_boot/custom_boot.img
	exit 1
fi

cat /mnt/sdcard2/dual_boot/custom_boot.img > /dev/block/platform/sdhci-tegra.3/by-name/LNX
sync; sync; sync

echo rebooting to Custom JellyBean

sleep 2 

reboot

in init.kai.rc change mount point of system to sdcard.

mount ext4 /dev/block/mmcblk1p2 /system rw

in fstab.kai change mount points to sdcard.

# Android fstab file.
#<src>                                                  <mnt_point>         <type>    <mnt_flags>                                                                         <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

# We remount because we first mount as rw in order to generate NVSI symlink. See init.rc for details.
/dev/block/mmcblk1p2           /system             ext4      ro,remount                                                                          wait
/dev/block/platform/sdhci-tegra.3/by-name/CAC           /cache              ext4      noatime,nosuid,nodev,journal_async_commit,data=writeback,nodelalloc,errors=panic    wait
/dev/block/mmcblk1p3           /data               ext4      noatime,nosuid,nodev,journal_async_commit,data=writeback,nodelalloc,errors=panic    wait,encryptable=footer

 

[tasinofan]

thanks for sharing the details!

 

[xdrc45]

Added cm10 kernel and boot scripts to first page.

Dev-Host - dualboot_cm10.zip - The Ultimate Free File Hosting / File Sharing Service

@vampirefo,
Can you help me to set up the cm10 kernel and boot scripts for dual boot?
I have my sd card partitioned and setup, now I'm just not sure which files go into the dual boot folder and what to do with the other files files and zips.
Thanks in advance for any help!

 

[vampirefo.]

@vampirefo,
Can you help me to set up the cm10 kernel and boot scripts for dual boot?
I have my sd card partitioned and setup, now I'm just not sure which files go into the dual boot folder and what to do with the other files files and zips.
Thanks in advance for any help!

First you need to decide where your cm10 is going to be installed, if on sdcard you would need to place jb_cm10_sd.img on sdcard in folder called dual_boot then copy reboot-sdcard to system of both OS, also you would need to edit other script reboot-tablet and add your other OS boot.img here as well as placing the other boot.img in folder dual_boot, reboot-tablet would need to be added to both OS system bin and permissions set.

basically you need on you sdcard

a folder called dual_boot in that folder you need both boot.img one for each OS,

in each system bin you need both scripts, reboot-tablet, reboot-sdcard you can rename them if you want.

each script needs to point to a different boot.img you then edit update script on the cm10 rom and have it install to sdcard, once done you can boot into regular OS use adb to push the scripts or use root file manager and set permissions.

I have also included zips, "vampirefo_jb_cm10_sd.img_.zip" they allow you to use cw recovery to flash boot.img rather than using scripts.

 

[tpaine]

I set up the tab for mcl201 on sd card for dual boot. No problems, not even playstore. Using a class 4 card is a bit slow to setup, but very usable.

I'm not quite sure why the bootloader does not have to change, but it works well as it is.

I noticed the cm10 file links are no longer valid. Next step, cm10.1

Thanks for all your work.

 

[tpaine]

When attempting to load my modified cm10.1 zip file in recovery, I get an E:Error in .../cm10.zip (status 0). Can you offer any clues as to where to look in the updater? It seems quite different from the mcl201 rom updater, and after trying several changes, I'm not sure what is wrong.

 

[vampirefo.]

When attempting to load my modified cm10.1 zip file in recovery, I get an E:Error in .../cm10.zip (status 0). Can you offer any clues as to where to look in the updater? It seems quite different from the mcl201 rom updater, and after trying several changes, I'm not sure what is wrong.

I don't know about 10.1 most likely you need a different recovery or bootloader, you can go into advanced on cwm recovery report error then select show error and see if that helps you.

 

[tpaine]

Thanks for the info. That does show where the error occurred.

Getting cm10.1 to dual boot is extremely complex. Its at the limits of my capability. Any chance of you updating the dual boot cm10 links?

 

[vampirefo.]

Thanks for the info. That does show where the error occurred.

Getting cm10.1 to dual boot is extremely complex. Its at the limits of my capability. Any chance of you updating the dual boot cm10 links?

I don't have them, this upload site removes files that aren't regularly downloaded. I quit using any OS above stock ICS on my Lenovo A2109 cause I need GPS, for work.

 

[tpaine]

You can test any OS, rom, tweak, without losing or touching your installed OS. no fear of not being able to revert back to previous OS.

You will always have access to an OS, If you screw one up boot into the other. Ever wonder if one app runs better on a particular OS? a simple reboot and you can find out.

This guide will be dual booting ICS and JellyBean, you can use any OS you want as long as your tablet supports it.

first thing is to setup micro sdcard

Ok, I'm starting to understand. The kernel source build modules are needed to modify the boot.img to mount the ext-sd . Can you direct me to a guide or link the kernel modules required ?

 

[vampirefo.]

Ok, I'm starting to understand. The kernel source build modules are needed to modify the boot.img to mount the ext-sd . Can you direct me to a guide or link the kernel modules required ?

????????????

What I don't understand your question.

 

[tpaine]

I am setting up an ubuntu-64 development system. It looks like the coby 7065/8065 run from sdcard is related to this dual boot setup.

 

[vampirefo.]

I am setting up an ubuntu-64 development system. It looks like the coby 7065/8065 run from sdcard is related to this dual boot setup.

These are different methods, as the 7065 burns the bootloader to sdcard, and the a2109 doesn't, the a2109 requires a working bootloader the 7065 doesn't.