• After 15+ years, we've made a big change: Android Forums is now Early Bird Club. Learn more here.

Root Casio_C771_m130_Stock_Rom

Hey guys,
So in trying to make a custom ROM, I made several versions to try and build. I took the base of Monkeytools's ROM, and de-bloated it, added a custom boot animation, and updated Superuser apk and binary. I installed everything to system/bin directory, not system/xbin. I also did this on my phone. I went to use the update.zip, and restarted. My phone bricked. I'm going to guess that this brick had something to do with me moving the busybox installation.
If someone with more knowledge about this could confirm that would be great.
 
Upvote 0
I'd like to refine my question and post some notes to have them verified if anyone knows.

First: can you describe what happens on boot?

Second: did you ever successfully unlock the bootloader?

My reasoning behind this second question stems from your mentioning of moving system files. my understanding is that in a locked bootloader there is a signed file in the system that if the locked boot loader does not find it will not boot. this is supposed to be a method to prevent peeps like us from doing what we are doing put in place by manufacturers. As far as I have read and seen no one has posted reliable information on unlocking the bootloader.
the thread that says it does only uses the bootloader to install a cust recovery, but does not unlock it.
 
Upvote 0
Yes the bookcase is still locked. The system apps have nothing to do with the bootloader. I will get up with pollster tonight and see if I can help. If the phone starts to load at all he should be able to plug into pc and adb reboot recovery. And restore nandroid back up. I did this before trying out a ROM I had made that wouldn't boot up.
 
Upvote 0
Do you get any screen at all. When you try to turn it on.

Yes. The basic G/zone, then after a few seconds the g'zone lights up, but nothing after that. The red light for hard factory reset does not come up as well. This was the same problem that I had on my other phone when i erased the /system partition.
I tried to connect to the modem side using QPST, (could not find any helpfull menus on RevSkills), and I can get it into debug and download mode (modem version.) It was able to detect the user partitions, but not able to download them, and no option was their to upload.
You guys got any ideas?
 
Upvote 0
To MonkeyTools:
He is not talking about the android system apps, if that is what your are referring to. He is talking about the "modem side" of the phone.

To LimitedRelease:
My boatloader is still locked. I never made any attempt to unlock it. What you are saying makes sense. If there is a way to unlock it, then what would that do?
Sounds like there is hope?
 
Upvote 0
Upvote 0
To MonkeyTools:
He is not talking about the android system apps, if that is what your are referring to. He is talking about the "modem side" of the phone.

To LimitedRelease:
My boatloader is still locked. I never made any attempt to unlock it. What you are saying makes sense. If there is a way to unlock it, then what would that do?
Sounds like there is hope?

Can you adb to the device? Did you install the recovery information?
With my bootloader unloaded, If that's what it is you can adb to recovery and flash it back. Just thinking out loud


http://androidforums.com/showthread.php?t=671930

Casio C771 Unlock Bootloader and Install GNM Recovery via Fastboot
 
Upvote 0
Can you adb to the device? Did you install the recovery information?
With my bootloader unloaded, If that's what it is you can adb to recovery and flash it back. Just thinking out loud


Casio C771 Unlock Bootloader and Install GNM Recovery via Fastboot - Android Forums

Casio C771 Unlock Bootloader and Install GNM Recovery via Fastboot
I'm just going to summerize what I have:
G'zone loading comes up. Nothing after that. (/system is empty)
Device manager shows Casio USB composite device, Casio Virtual Serial Port COM13
Device manager does not show Android ADB interface nor Casio C771 Bootloader Interface.
I can NOT adb the phone.
I can NOT acccess the bootloader on the android, so no fastboot.
I CAN access the Download and Debug on the modem side.
QPST works for connecting to the modem side.


My guess is only two things can happen to make it work.
1. The Modem Bootloader has access to the "3ed Party User Partitions" code for the COM port in AT (whatever that is) can be made to push files to the /system directory.
2. The Modem Bootloader has access to the "3ed Party User Partitions" code for the COM port in AT (whatever that is) can be made to push the file that the locked bootloader needs in order to start. It would go to recovery. (this depends on if LimitedRelease's idea of the locked bootloader is correct)
3. The Modem Bootloader can have the COM port in AT (whatever that is) can be made to reboot into the recovery.

Now that I think about it, when the phone boots, it shows the unlit g'zone, then the g'zone loading. (goes to modem bootloader). When the RECOVERY is loading, it shows the unlit g'zone, then barely shows the g'zone loading when it goes to recovery. I know it sounds riskey, but what if I removed the bootloader. would that force it into recovery, having to boot into something?

Also, could someone explain what the difference/advantages of are having an unlocked bootloader versus locked? LimitedRelease did a good job describing locked, but what does unlocked do?

Thanks you guys for all your help so far with this.
 
Upvote 0
this article may help provide prospective.
I know I remember reading articles on the C771 bootloader from 2011 timeframe that noted it was 'weird'

anyways, unlocking the boot loader basically refers to making the bootloader proceed with the boot order (initialize hardware,load the OS, etc) no matter what is written in the locations where the boot sequence looks to boot. (generically called sector 0) I'm not familiar enough with android to know if this is perfectly accurate for the android os, however this is how other Linux distros work.
for example the Linux bootloader called grub (and grub2) can boot to multiple OSes (including windows) by partitioning a drive with multiple sectors as the starting sector for a given OS

each droid phone due to their unique hardware is likely to have with own special bootloader I'd expect.

edit: forgot link.. oops
http://www.addictivetips.com/mobile...-bootloader-on-android-phones-complete-guide/
 
  • Like
Reactions: Willster419
Upvote 0
this article may help provide prospective.
unlocking the boot loader basically refers to making the bootloader proceed with the boot order (initialize hardware,load the OS, etc) no matter what is written in the locations where the boot sequence looks to boot. (generically called sector 0)

ok thank you very much. I feel enlightened. Appareently, there are a lot of phones on ebay saying, "only boots to g'zone" or, those that know, "boot locked" very nice to know.

so, in theory, the bootloader unlocked would load (or attempt to load) what it can given any circumstance. again, in theory, instead of becoming bricked, would it load the OS, or lack of, where the hard reset keys can be pressed, or would it boot into recovery, seeing nothing else to boot in to?

i'm just guessing here.
 
Upvote 0
this article may help provide prospective.
unlocking the boot loader basically refers to making the bootloader proceed with the boot order (initialize hardware,load the OS, etc) no matter what is written in the locations where the boot sequence looks to boot. (generically called sector 0)
found the thread about the "weird" bootloader:
http://androidforums.com/commando-all-things-root/333496-interesting-security-commando.html

ok so I bought a new phone from ebay with a clean esn, and i'm sending my old phone back to casio to try to fix. here is what I will do:
When the purchased comes in, I will try the other rooting method that uses fastboot. According to GNM, a locked bootloader blocks the fastboot commands. I will try to use fastboot with locked bootloader. If that does not work, then I will unlock bootloader and try again. If that works, not only can I proceed with the rooting process, but it can confirm that the bootloader is unlocked (i think).
When (and if) my other phone comes back from casio, I might unlock the bootloader and re-create what happened to my phone (wiping the /system partition) to see what happens. What do you think will happen, and is this idea even a good one?

I think it will boot, skip the files that arn't there, and continue to /boot? then can adb?
The /boot partition would still be there, so would that make it work?
 
Upvote 0
The boot loader only holds the system set up file. And kernel and security. If you wipe system it wipes all sytem file this means it has nothing to boot too. This phone cant be flashed with fastboot to the recovery because it is locked down. I tried last night to fastboot a new boot.img. it would not flash. There also is no recovery in bootloader. The recovery I think is somehow part of the system side of the phone.I have pulled apart the bootloader. Looking for a way to by pass the securty or unlocked it. Will post more when I get a chance. The boot loader that I pm you willster have adb ready to go in it. There is no need for adb insecure now. I will include it in my rom.
 
Upvote 0
On the post that rasta4rest posted, he was able to fastboot a recovery image. In that case you could flastboot a boot image?
so in theory, if one could fastboot your boot.img to the phone, would it then have adb and/or fastboot abilities, even if the /system partition is erased? Maybe even able to then adb reboot recovery (if GNM recovery is installed)?
also, what did you use to open and edit the img file?
thanks
 
Upvote 0
here is what we did to flash recovery. (((I've guessed that "Bypass Booting" was bootloader lock "bypassing", but how can i use that to install recovery from stock device without root access ?

Here's the step by step guide assuming everyone here has been enabling "bypass booting" - ON & C771 Boot Loader Interface driver installed on their device , just googling it or search on this forum to get the correct driver:))) what we did is by pass the locked bootloader to flash the recovery. we didn't flash recovery from bootloader. and I used dsaxda rom kitchen to pull apart the bootloader.
 
Upvote 0
ok good to know. I looked at fastboot options and found that you can install a update.zip which can have the bootloader you made. SO, then adb is available if /system is wiped, right? It sounds like you could adb reboot recovery or bootloader if the above were to happen? then you could put the /system back on? it sounds like we have a way to "unbrick" a phone?
when my 2ed phone comes in i'm willing to test this to make sure. or maybe we can have someone else test it who is willing?
sorry for all the questions, just becoming exited that it might be unbrickable:p
 
Upvote 0
This will depend on if the boot loader is still intacted. After a system wipe is done.it sounds like it is from the way you are saying. That the gzone still comes up and it starts the loading screen. But there is no system to load because it has been wiped out. Have you tried to ask verison if they can flash your phone.Isay this because some carriers can take a phone that Iis not from them and flash it to there service. Dont know if they can do this phone or not.
 
Upvote 0

BEST TECH IN 2023

We've been tracking upcoming products and ranking the best tech since 2007. Thanks for trusting our opinion: we get rewarded through affiliate links that earn us a commission and we invite you to learn more about us.

Smartphones