Dual kernel choice at boot time

[opengl1971]

Thanks leolas for the info , this explains a lot.
Can any one please explain the MTD blocks solution in more detail ?

[meddem]

Hello to everyone. Maybe kboot is what you are looking for.

http://forum.xda-developers.com/showthread.php?t=1522024

I was using the kboot with my old tablet to boot between GB, and froyo, and Linux.

I don't know if this can be applied on our sticks though.

[Finless]

Not exactly the same, picuntu flash a kernel with a initramfs, dont know exactly what is in this, cause I started with picuntu 2 days ago, if you flash a kernel alone picuntu don't works.

Good point! So if we have a boot.img with kernel in it, it will have initramfs. Thus theoretically you could flash this boot.img to recovery space and it should boot.

RK chips boot like this.
1) If kernel is in boot.img then on boot it will use kernel from boot.img.
2) If kernel is not in boot.img then it will boot and use kernel.img
3) If kernel is in recovery.img then boot to recovery will use kernel in recovery.img
4) If kernel is not in recovery.img (like CWM does it) then it will boot to recovery and use kernel.img


Bob

[leolas]

Re: Dual kernel choice at boot time

Good point! So if we have a boot.img with kernel in it, it will have initramfs. Thus theoretically you could flash this boot.img to recovery space and it should boot.

RK chips boot like this.
1) If kernel is in boot.img then on boot it will use kernel from boot.img.
2) If kernel is not in boot.img then it will boot and use kernel.img
3) If kernel is in recovery.img then boot to recovery will use kernel in recovery.img
4) If kernel is not in recovery.img (like CWM does it) then it will boot to recovery and use kernel.img


Bob

In fun cwm recovery there is a kernel inside for most of the devices, if there is not a specific image for the device, and we use the generic recovery (no kernel embedded) then it uses the kernel in kernel partition, I am now far of home (some days in beach with the family), but when I return home I will try to get more info about this. And the great Bob maybe can make for us a boot with kernel inside or I will try(I know how extract the kernel from boot but I dont know how pack it again), need to learn how do it.
This devices are really fun and great to learn.

[opengl1971]

Did you or bob had a chance to look at making a boot with kernel inside ?
Sorry for asking , I know that you two are very busy helping the whole community.

[opengl1971]

It worked , (only with the stock firmware) , what i did is:

1-Flashed stock rom (720p version) for imito mx1.
2-Flashed stock boot 1080p version into the recovery space.
3-The 720p version can be accessed from normal rebooting or unplug/replug the usb cable
While the 1080p version can be accessed by rebooting to recovery.

As i mentioned before this solution worked only with stock firmware , unfortunately not with
Finless 1.7 or 1.5 firmwares , i am suspecting that it has something to do with partition sizes
Which is changed in finless roms to give you more app space (not sure of course if this is the reason)

I would consider this a perfect solution if it worked with finless rom.
Any sugesstions or ideas To make this work with finless rom will be really appreciated.

[Finless]

I am pretty sure it is because the stock ROM has a kernel and ramdisk in boot.img and my ROM does not. I take it out of boot.img so people can use other kernels easily. So that is probably why.

When I get some time I am sure I can make a dual boot for you guys with my ROM.

Bob

[opengl1971]

Thanks bob for the explanation , i can verify what you said my self , because i tried with cwm
I made 2 system backups for 1080p and 720p of you rom then i needed to restore both
The kernel and the boot to make the resolution change , but when i did the same with the Stock rom i only needed to restore the boot to do the resolution change.

It will be really great bob if you do a dual boot for us , we got used to your roms so much that
Using the stock rom is like going to stone age , thanks again.

[opengl1971]

A little update:

When rebooting to recovery to access 1080p mode
When in 1080p mode the internal nand storage shows up as corrupted although it isn't
When rebooting normally to the 720p mode the nand storage shows up as working correctly.

[leolas]

A little update:

When rebooting to recovery to access 1080p mode
When in 1080p mode the internal nand storage shows up as corrupted although it isn't
When rebooting normally to the 720p mode the nand storage shows up as working correctly.

Yes, seems that you need a boot.img with kernel inside to make posibble the dual boot.

[opengl1971]

Yes, seems that you need a boot.img with kernel inside to make posibble the dual boot.

Thanks leolas for the reply , it works ok and boots at 1080p and everything works except the Apps that depend on the internal sd to work , what i don't understand is why the external sd And usb storage work While only the internal sd doesn't work ?
If the kernel is needed to access the internal sd shouldn't The external sd and usb storage
Be inaccessible too ?

[leolas]

Re: Dual kernel choice at boot time

Thanks leolas for the reply , it works ok and boots at 1080p and everything works except the Apps that depend on the internal sd to work , what i don't understand is why the external sd And usb storage work While only the internal sd doesn't work ?
If the kernel is needed to access the internal sd shouldn't The external sd and usb storage
Be inaccessible too ?

What did you install in the recovery?
A kernel.img alone?
Ok, now I see you installed the stock boot.img with the kernel inside. We need to compare both boot.img to see what is the problem. I am ending with a WiFi dongle problem that I had, and helping a guy to make it work. If I get some free time I will try to do this.

[opengl1971]

Thanks leolas i will hold on to that.

[opengl1971]

Any news about this , leolas or bob ?

[leolas]

Re: Dual kernel choice at boot time

Sorry, i am playing with the new kernel sources and learning some about modding. I will try with it when I have some time.