ADB Curiosity - recognizes phone in normal boot, but not in fastboot
I'm cannot re-root my phone. I originally, successfully, rooted my GNex using the Samsung naked drivers from the XDA forums. I somehow fouled up my phone by installing and playing around with some (root-required) apps. So I reflashed back to stock images posted by Google. I did run into a lot of adb problems when I did that. My Gnex wasn't recognized as an adb device. Then suddenly it was (I don't know why) and I quickly reflashed back to stock.
But then when I went to re-root, adb wasn't working again. (Yes, I remembered to turn USB-debugging back on.) I tried everything I had read online, but nothing worked.
Here's the strange part. In trying different strategies to get adb to work I noticed when connecting my phone to my Windows PC, while it was on and normally booted into ICS, I could bring up a command prompt and adb would work. But when I used "adb reboot bootloader" the phone would cease being recognized and no adb commands would work. It also wouldn't work if I went into fastboot by pressing volume up/down & power. But then if I select "Start" to boot normally, adb would work again once boot had finished.
I also notice that when adb works (while the phone is normally booted), the phone is listed by Windows Device Manager as "Samsung Galaxy Nexus ADB Interface". When adb doesn't work (while the phone is in fastboot) it is listed as "Samsung Galaxy Nexus Bootloader Interface". I did try to manually install the USB driver and choose "Samsung Galaxy Nexus ADB Interface" as the hardware when in fastboot but that option disappears.
Does this mean anything to someone who knows what they're doing? I'm sorry my first post is a help needed post but I appreciate any and all responses.
Last edited by blue whale; February 3rd, 2012 at 10:36 AM.
Re-rooted with driver combo, but still have questions
Well, I was able to re-root my phone. Ultimately, what worked was a combination of two drivers in a particular order. First, I disabled my phone in the Windows Device Manager and uninstalled the current driver. I unplugged and rebooted both my phone and computer. Without plugging my phone back into the computer, I installed the driver from the Samsung site. Then, with my phone booted into Android, I plugged it into the computer. I pushed the su.zip file over to the phone with adb. Then I used "adb reboot bootloader" to boot into recovery. The phone hung there with a "waiting" message. At this point I manually upgraded the USB driver with the Samsung naked driver from XDA. Once my phone was recognized I used fastboot to flash CWM.
I think one problem I had was that Windows would automatically install a driver of its choice and it would either block or overwrite any driver I would install.
Of course afterword, my phone went back to being unrecognized as an adb device.
Am I missing something? How do I get adb to work in recovery mode?
The Following User Says Thank You to blue whale For This Useful Post:
I've been doing more reading and found out I've been confusing fastboot and recovery modes. At this point I'm not sure that adb commands are intended to work in fastboot mode. But obviously even if they are, there are ways to root without doing so, as I just did.
But I would like to know if there is a hardware/button-combo method to boot into recovery with the GNex. If anyone knows, please, leave a comment.
Until then, I'll continue reading on my own and trying to learn more.
I think I get what you are asking, so let me take a quick shot at it...
The two modes you are asking about are (as you've discovered) distinctly different, but their uses and context can be a little confusing.
fastboot (or bootloader) mode is the state where now operating system or custom recovery is running--its really just the bootloader that you interacting with on the phone. The off-phone means of communicating in that mode is via the fastboot utility (hence the dual names of fastboot / bootloader mode). fastboot can be used for flashing new images and installing updates.
adb mode is when either an adb (Android Debug Bridge) daemon (background service) is running when Android proper (with USB debugging being enabled) or when a custom recovery is running. adb doesn't know how to talk to the device when in fastboot / bootloader mode because it needs some kind of kernel running that can host the adb daemon that the adb client (i.e., the component on your PC) to communicate with.
And, as you've seen, the USB drivers that are used by adb and fastboot are a little different--finding one that works nicely with both is a little tricky (I've had great success with the Naked 1.7 drivers (How to install the adb & fastboot USB drivers (MS/Windows users only)).
Below is a link to a post I made about how to enter fastboot / bootloader mode and/or custom recovery.
from a powered-off state, press (and hold!) volume-UP and volume-DOWN and power (keep holding all three until you see the little green Android laying down with his chest plate open)
if you are already in fastboot / bootloader mode, you can issue the "fastboot reboot-bootloader" command to re-launch
if you are in an adb mode (i.e., USB debugging is enabled while Android is running or you have custom recovery (ClockworkMod) running), you can issue an "adb reboot bootloader" or "adb reboot-bootloader" command to put your phone in fastboot / bootloader mode
---------------------------------------------------------------------------- . Q: how to enter into recovery (custom or stock)?
A: several ways:
put your phone in fastboot / bootloader mode (see above) and use the volume up/down keys to toggle the mode (displayed at the top of the screen) to "Recovery" and select that mode by pressing the power button
Thanks, Scary Alien. That does clarify things and better directs my learning efforts. I realize now I've started a useless thread. In fairness, though, I think most beginners do a lot of research before asking questions. But as you can see, sometimes we think our problem is one thing when in actuality it is quite another. But I appreciate your forbearance and your help.
Another problem is that our play/experimentation devices are the same as our survival devices. It would be nice to have two sets of everything.
The Following User Says Thank You to blue whale For This Useful Post:
Thanks, Scary Alien. That does clarify things and better directs my learning efforts. I realize now I've started a useless thread. In fairness, though, I think most beginners do a lot of research before asking questions. But as you can see, sometimes we think our problem is one thing when in actuality it is quite another. But I appreciate your forbearance and your help.
Another problem is that our play/experimentation devices are the same as our survival devices. It would be nice to have two sets of everything.
Oh, your thread is not useless at all! There's so much information out there and its not all totally easily retrievable--you've often got to know what the right keyword(s) to search for and in what combinations. Often, the search functions don't really zero-in on what you need or the answer is buried too far down.
Asking questions is how we learn and that's very encouraged here at AF .
These drivers can be a bit fiddly, but I used the ones in GNex ToolKit and it was relatively painless. It did take me a couple of times connecting/disconnecting and switching between adb and fastboot until it was happy in both modes.
The Galaxy Nexus is the third official phone contracted by Google and the first phone to come with Android 4.0 Ice Cream Sandwich. Specs include a 1.2GHz dual-core processor, 1GB of RAM, 16/32GB of internal storage, a 4.65 inch 720p HD Super AMOLED... Read More
ADB Curiosity - recognizes phone in normal boot, but not in fastboot
and that's very encouraged here at AF 
