[idea] two ROMs on one device (aka dualboot)

[Guest Snap.IT]

Having the whole thing on SD would also make us to be able to boot more than two roms by either swapping the card or swapping files.

For me that looks like a good direction.

Or simply using different partitions on the same SD for different roms, exactly as you would do if you installed it in your computer (you can also install into different files as the bootloader would have the information which partition to boot), you can have a multitude of partitions, 16 1GB partitions on a 32GB card and you will still have twice as much space as stock for each and 16GB for music, video and so on.

This would be ideal.

[Guest Snap.IT]

I tried editing boot.img ram disk I think the initramfs files lies here.I put some some dual boot supported initramfs scripts but it didn't fit the boot partition.So we have to make small sized dual boot supported scripts.will try soon.

I think it's a better option to use a bootloader and put the zImage on partitions, of course, the ideal solution would be a combined bootloader and recovery, that way you could leave one ROM intact on the phones internal memory and have it remain untouched.

[Guest Sulthekk]

I think it's a better option to use a bootloader and put the zImage on partitions, of course, the ideal solution would be a combined bootloader and recovery, that way you could leave one ROM intact on the phones internal memory and have it remain untouched.

That's why I was thinking on kexec... You can just place a kernel and an initrd directly in the root of the partition, and from now on you would only need to tell the loader program where the partition is, then it would find the necessary things by itself, since the paths would be the same for everytime. But I'm still doing a research on it as I'm not experienced with it, so what I say maybe isn't working... Handle it that way.

[Guest android@sam]

I got the right initramfs files and the kernels source which contains dual boot scripts.Just those are needed to be merged in zte kernel source and compiled.

[Guest Sulthekk]

I got the right initramfs files and the kernels source which contains dual boot scripts.Just those are needed to be merged in zte kernel source and compiled.

If it were that easy... I think any multiboot mod would need to be edited for the blade.

[Guest android@sam]

If it were that easy... I think any multiboot mod would need to be edited for the blade.

I know it's not that easy.both I have got another scripts which copy the rom and directories like /data /cache to sdcard and which setups the .config file for setting up the rom for dual booting

[Guest Sulthekk]

I know it's not that easy.both I have got another scripts which copy the rom and directories like /data /cache to sdcard and which setups the .config file for setting up the rom for dual booting

.config? Please tell me that you aren't trying to insert a kernel config into an existing rom! :(

[Guest android@sam]

.config? Please tell me that you aren't trying to insert a kernel config into an existing rom! :(

no man it tells the init scripts where are the yaffs images like caches.img,data.img are to be mounted in /sdcard

[Guest Sulthekk]

no man it tells the init scripts where are the yaffs images like caches.img,data.img are to be mounted in /sdcard

Whew! Sorry for asking such a question, but I that's something I was scared of...

What solution are you trying to implement? Maybe I could help with the kernel?

[Guest android@sam]

As you said in few post back,i researched for the initramfs,etc things and i found some helpfull things.I found that some changes are to be made in init.c and initramfs.c in /init/ folder in kernel source.Also the ramdisk is to be modified.And if we press a key within 3 seconds from the boot the phone will boot into sdcard rom.

[Guest Sulthekk]

As you said in few post back,i researched for the initramfs,etc things and i found some helpfull things.I found that some changes are to be made in init.c and initramfs.c in /init/ folder in kernel source.Also the ramdisk is to be modified.And if we press a key within 3 seconds from the boot the phone will boot into sdcard rom.

Okay... Do we need to patch the second rom's initrd/kernel too?

Edited July 16, 2012 by Sulthekk

[Guest android@sam]

Okay... Do we need to patch the second rom's initrd/kernel too?

no need to patch the second rom's kernel.Only we have to modify first rom's kernel for dual booting Edited July 16, 2012 by android@sam

[Guest Sulthekk]

no need to patch the second rom's kernel.Only we have to modify first rom's kernel for dual booting

Well, that's good, because that means that we only need to modify the fstab for the second rom, wich is as simple as running diff and patch. :)

[Guest android@sam]

Well, that's good, because that means that we only need to modify the fstab for the second rom, wich is as simple as running diff and patch. :)

Yes and we can compile a recovery wirh dual boot option also

[Guest Sulthekk]

Yes and we can compile a recovery wirh dual boot option also

That would solve the issues for flashing the second rom, but... That solution would also mean that we have to compile for every new version. That's a great start, but having some kind of patcher to turn a normal boot.img into a multiboot boot.img would make more sense. What if we would check the differences between an ordinary and a patched initrd, and then apply them with diff & bsdiff... We could build an update.zip for it, Burstlam's kernel updater package is a great base, it has the tools needed to split and repack a boot.img, we would need to compile some tools to modify the initrd itself, though.

[Guest android@sam]

That would solve the issues for flashing the second rom, but... That solution would also mean that we have to compile for every new version. That's a great start, but having some kind of patcher to turn a normal boot.img into a multiboot boot.img would make more sense. What if we would check the differences between an ordinary and a patched initrd, and then apply them with diff & bsdiff... We could build an update.zip for it, Burstlam's kernel updater package is a great base, it has the tools needed to split and repack a boot.img, we would need to compile some tools to modify the initrd itself, though.

Can you link me to the Burstlam's tool?

[Guest Sulthekk]

Can you link me to the Burstlam's tool?

Huhh, that was a long ago, when the gb kernel source came out... Wait a minute, I will find it.

That was the thread:

Edited July 16, 2012 by Sulthekk

[Guest KonstaT]

...Burstlam's kernel updater package is a great base, it has the tools needed to split and repack a boot.img, we would need to compile some tools to modify the initrd itself, though.

Fyi, It's koush's AnyKernel.

[Guest android@sam]

Huhh, that was a long ago, when the gb kernel source came out... Wait a minute, I will find it.

That was the thread:

thanks

[Guest Sulthekk]

Fyi, It's koush's AnyKernel.

Thanks for the info, I wasn't aware of that.

[Guest android@sam]

Where i can found the instructions for the tool?

Edited July 16, 2012 by android@sam

[Guest Sulthekk]

Where i can found the instructions for the tool?

I don't think anybody ever wrote a guide for it. That's basically an Edify script which calls binary command line tools to do the job. It needs 2 things to know: Edify and how to run a cli application. But first, we should check it out that we can create a working multiboot image, because writing a patcher is step further away. I just mentioned it because it can fix an important problem (make it working with any boot.img).

[Guest android@sam]

I don't think anybody ever wrote a guide for it. That's basically an Edify script which calls binary command line tools to do the job. It needs 2 things to know: Edify and how to run a cli application. But first, we should check it out that we can create a working multiboot image, because writing a patcher is step further away. I just mentioned it because it can fix an important problem (make it working with any boot.img).

Thanks!By the way just got the zte kernel source ad will start the compiling soon!

[Guest android@sam]

Tried the compiling.Compiled successfully but it breaks the recovery.So will have to try something different.

Edited July 17, 2012 by android@sam

[Guest Sulthekk]

Tried the compiling.Compiled successfully but it breaks the recovery.So will have to try something different.

Is the code looking for a specific button or any button triggers the alternate boot? What about changing it to look for a specific keycode, for example the home or the back button?