Need Help: How to debug boot crashes? - Google Pixel 4a Questions & Answers

I am trying to build a custom ROM for pixel 4a. I was able to build the images successfully. After I flash, the phone boots but gets stuck in Google logo. How can I debug this? Device is not listed in adb at this point of time. Any suggestions/guide to debug the device preferably without rooting in this scenario?

I'm assuming you are hitting a problem with the kernel. Your best, maybe only option is to connect a serial console to the device. Luckily, it seems you don't have to disassemble the phone to reach solder pads anymore, but you do have to create an adapter to get console out of the USB port. I found these links that might be helpful. I did not find anyone selling pre-made adapters.
Serial debugging:Cable schematics - postmarketOS
wiki.postmarketos.org
GitHub - Peter-Easton/android-debug-cable-howto: This is a simple how-to to create your own android kernel debugging cable using commercially available parts.
This is a simple how-to to create your own android kernel debugging cable using commercially available parts. - GitHub - Peter-Easton/android-debug-cable-howto: This is a simple how-to to create y...
github.com
GitHub - google/usb-cereal: USB-Cereal is a debugging and development tool for designs that use USB-C port and bring out serial TX/RX lines into SBU1/2 pins. USB-Cereal is made compatible with both 1.8V and 3.3V signalling.
USB-Cereal is a debugging and development tool for designs that use USB-C port and bring out serial TX/RX lines into SBU1/2 pins. USB-Cereal is made compatible with both 1.8V and 3.3V signalling. -...
github.com
If the kernel finishes booting, and you have an Android problem, you might have other options.
If storage can be mounted, you could dump logs there.
If the network is up you can dump logs remotely. You'd need another device on the network to receive the logs. A USB LAN dongle might be better than WiFi for this...
There was a bootsplash mod that printed console messages. I don't know how easy it is to just write on the screen but if you can leverage an existing project like this it might be manageable.

Are you not using any kind of emulation for testing prior to pushing to the device? Emulation will give you the capability to capture dump/log data for analysis.

Actually I have made few changes in the some xml files that goes into vendor.img. For emulators, we dont need vendor .img right?

Related

Serial port kernel and wlan.ko, ready to go

Find included a 2.6.27 kernel and corresponding wlan.ko with serial port enabled. This will work with JF, mikhael's build and so on that use the 2.6.27 kernel. Wifi works, bluetooth works, all that stuff works.
Serial port is /dev/ttyMSM2 with default at 9600 baud. I am turning my ADP into the brains of a UAV, so this should let me control servos with it.
Have fun! 2.6.29 (or whatever will be current) coming when I get off my lazy bum and move to it.
Installation is the usual "rename to update.zip, put in sdcard, start the phone in recovery mode" dealie.
BACK UP YOUR BOOT.IMG AND /SYSTEM/LIB/MODULES/WLAN.KO if you want to revert!
Here's a newer version with a terminal program (dterm, recompiled for g1/g2), or just the terminal by itself. If you flash the terminal ends up in /system/sbin and automatically goes to /dev/ttyMSM2 (see source), again it's just dterm with some cleanups.
By the way, does anyone care about this stuff at all?
I couldn't upload the kernel so here it is http://www.spirit-plumber.com/portfolio/robotics/kernel_serial_term.zip
It sounds very promising/interesting but I'm not exactly sure what it does. Does is it enable accessing the baseband via serial or something? This is something that was used on the original iPhone to try to unlock it.
I think if you explain more clearly what it does then more people will seem interested, & remember no contribution here is a bad one, someone will have a use for it.
It gives you a serial port that can be used as a device rather than just for debugging, as shown here
http://www.instructables.com/id/Android_G1_Serial_Cable/ (not by me btw) This software stuff makes it usable for general purpose IO. That allows a G1 and an inexpensive microcontroller, arduino/picaxe/etc to control servos, talk to a second GPS, and so on.
I develop autopilots for RC planes and the G1 would be a great platform for that since it has a gps, compass, accelerometer and camera already integrated in a relatively small/light package.
Also, ROBOTS! http://hackaday.com/2009/01/25/forknife-android-g1-controlled-robot/ This was done using the audio port, but having a serial port on board bypasses all the DTMF stuff and allows for a lot more bandwidth. (Also not by me, if you do want to see stuff by me, search spiritplumber on youtube!)
I'm also very interested in such a kernel as a friend and I are interested in interfacing a phone to a serial robot controller.
However, I am currently running Cyanogen 4.0.4 on a MyTouch and loading this kernel effectively breaks the phone. No radio, GPS, etc. and many apps are missing/broken. The serial port does work and we got it talking with our robot but otherwise it's not much use to me.
So atm it's either a phone or an overly expensive microcontroller but not both.
You could submit the patches to cyanogen to see if he'd be willing to incorporate it in his build.
this is kernel version 2.6.27 and i think the build you use has kernel 2.6.29 which is why everything'd break. i will build 2.6.29 at some point, for now use a build that still use .27? i useJF151 with good results.
Hi, I'm interested in this stuff, I just wonder how can I use this to interface G1 to Arduino? any idea/tips will be helpful. TIA.
You end up with a new device, /dev/ttyMSM2 which is a standard issue serial port that can be used to talk to microcontrollers. The voltage is 2.8V which means it will work with a 5V micro in the phone-->micro direction, but if you want to go the other way you'll need a divider.
(see the other thread i posted in for a schematic)
I should probably get cracking on a donut version
Wow
Interesting stuff. I just wish I had the ability to take advantage of this. I think this would bring it one step closer to being able to use the G1 as an OBD-II car scanner. But I'm afraid that will take way more technical ability than I have.
Not really...
http://www.suntekstore.com/OBD2-16Pin-to-DB9-Serial-Port-Adapter-Cable-.html
http://www.instructables.com/id/Android_G1_Serial_Cable/
+ my kernel
Nice work
spiritplumber said:
...
I develop autopilots for RC planes and the G1 would be a great platform for that since it has a gps, compass, accelerometer and camera already integrated in a relatively small/light package.
Click to expand...
Click to collapse
Genius! Well done for bringing this all together!!!!
I found your thread while trying to investigate the same project you've done already - making an autonomous drone using the G1 !!!
- I'd be very interested to see videos/info/photos of your drone.
I've seen all the bespoke UAV controllers on DIYdrone.com, but was more interested in the challenge of making my G1 with all it's sensors directly control a servo controller board via serial.
I'm a bit worried that the screen must stay on, which will burn through the G1's battery in no time! - is this still necessary?
I'm really impressed and thankful for what you have done, and making it public!!!
I'm currently on Cyanogen 4.0.4. so I guess the first step is to back track to an earlier Kernel version...
Unless you're close to rebuilding 2.6.29 ???
Thanks for the 'instructables' for the cable too, I've ordered the bits and hope to test in the next few days - ironically I found that before this thread!
Hmmm...
I've just studied your cable making instructions and have some questions!
The USB-Serial converter board... is that any use at all other than a PC interface?
I shouldnt actually need this to talk directly to another serial device from my G1?
- I got the impression the USB/Serial board was to convert the G1's USB to Serial...
Could I send a serial TX messages directly from the break-out board to a serial RX pin... (Servo controller) does that sounds correct?
Sorry for the torrent of questions...
If you want to talk to a different device you just need to flip pins 2 and 3 on the serial port and use a male rather than female connector so yes you can definitely do that!
In fact you can do two at the same time: Here's me using the G1 to relay data from a GPS to a servo controller. If you'd like the schematics for that let me know. If you have any sort of work related to this DEFINITELY let me know.
By the way, I'm using a 74HTC14 for doing the level shifting and inverting: it's a very cheap part and also has the advantage of cleaning up the waveform nicely. Or you can use some transistors.
EDIT: Attachment is being stupid so go here for photos: http://spirit-plumber.com/robotseverywhere/gallery/images/other/gphone/
spiritplumber said:
If you want to talk to a different device you just need to flip pins 2 and 3 on the serial port and use a male rather than female connector so yes you can definitely do that!
In fact you can do two at the same time: Here's me using the G1 to relay data from a GPS to a servo controller. If you'd like the schematics for that let me know. If you have any sort of work related to this DEFINITELY let me know.
By the way, I'm using a 74HTC14 for doing the level shifting and inverting: it's a very cheap part and also has the advantage of cleaning up the waveform nicely. Or you can use some transistors.
EDIT: Attachment is being stupid so go here for photos: http://spirit-plumber.com/robotseverywhere/gallery/images/other/gphone/
Click to expand...
Click to collapse
Hi Spiritp,
Thanks for your comments, I'll give that a whirl then!
I'll definitely keep you posted!
My basic plan is:
Use accelerometer for auto-leveling control, use pre-defined GPS routes so I know the take-off / landing site altitude above sea level, and eventually get the G1 to take photo's at GPS waypoints.
Probably ambitious considering my electronics knowledge, but I'll keep you posted with progress.
If you have any pointers of how to send Serial commands from within the Android App layer, I'd really appreciate it.
With so many 'rooted' applications doing kernel based tasks I'm pretty sure it'll be possible... but I'm also fairly green on linux & java, so this will be a challenge for sure. (Time to hack my way through other people's work and understand what's going on!!!)
Thanks for your response,
Andy
spiritplumber said:
By the way, I'm using a 74HTC14 for doing the level shifting and inverting: it's a very cheap part and also has the advantage of cleaning up the waveform nicely. Or you can use some transistors.
Click to expand...
Click to collapse
Question 1:
When you say 'level shifting' is this to bring the TX/RX voltage to the same level? (i.e. 5v --> 5v, rather than 2.8v --> 5v)
Question 2:
If I plugged a 5v serial device into the G1's RX connector, would this damage the G1?
Question 3:
Please help explain how non-printing byte-level data (Servo commands) can be sent from DTerm... I've had a poke around on the internet but with no success...
Question 4:
I have installed your Kernel/DTerm... which runs DTerm ok, but the commands 'ls' return the error 'not found'.
- which worked before adopting your kernel..
Is this normal? How can I fix this?
EDIT:
Ok, I think I'm half way there... I've now bought one of these:
http://www.coolcomponents.co.uk/catalog/product_info.php?products_id=194
//
spiritplumber said:
If you want to talk to a different device you just need to flip pins 2 and 3 on the serial port and use a male rather than female connector so yes you can definitely do that!
Click to expand...
Click to collapse
Reminds me of the HP48 token ring networks. http://www.hpcalc.org/details.php?id=3603 In essence, device 1 would transmit data to device 2. Device 2 would see that the packet was meant for a different device and retransmit the packet to device 3, the intended recipient. If device 2 had been transmitting a packet to device 1, it would have passed through 3 on the way back around. Adding another device to the network was as simple as breaking the chain and adding a new one. Building the cables to do that wouldn't be too difficult.
Level shifting:
Internally the G1 uses 2.8 volts. This is nice if you've a 5V interface because:
On going G1--->other part, 2.8 is high enough to register as "high", you may need a pullup resistor (try 10k).
On going other part--->G1 you just need a voltage divider! That's two resistors of equal value, this makes the other part effectively output at 2.5v which the G1 will happily accept! (If this confuses you, see "voltage divider" on wikipedia..... it's literally just 2 parts). Here's a picture on page 5: http://forum.xda-developers.com/showthread.php?t=496976&page=2
If you need to do stuff in that sense I recommend just having the servo controller take in ascii stuff. Or you can modify dterm. Or I can give you a modified copy of dterm that has that functionality let me know!
If you use a 3.3V microcontroller such as the Parallax Propeller, just slap two 1KOhm resistors on the rx and tx lines and go do stuff: it works.
Controlling servos via G1 is very painless and easy, I already do that, let me know if you want tips.T
spiritplumber said:
Level shifting:
Internally the G1 uses 2.8 volts. This is nice if you've a 5V interface because:
On going G1--->other part, 2.8 is high enough to register as "high", you may need a pullup resistor (try 10k).
On going other part--->G1 you just need a voltage divider! That's two resistors of equal value, this makes the other part effectively output at 2.5v which the G1 will happily accept! (If this confuses you, see "voltage divider" on wikipedia..... it's literally just 2 parts). Here's a picture on page 5: http://forum.xda-developers.com/showthread.php?t=496976&page=2
Click to expand...
Click to collapse
That's excellent, I think I have a solution for the voltage, but thanks a lot for your electronics expertise!!!!!!!
spiritplumber said:
If you need to do stuff in that sense I recommend just having the servo controller take in ascii stuff. Or you can modify dterm. Or I can give you a modified copy of dterm that has that functionality let me know!
Click to expand...
Click to collapse
I'm actually using a Pololu micro serial servo controller (SSC) - I'm fairly sure it doesnt support ASCII characters, the manual only explains how to compile a '3 byte sequence' :
To set the servo position, send a sequence of three bytes. The first byte is a syncronization value that must always be 255. Byte 2 is the servo number, and it can be 0-254. Byte 3 is the position to which you want the servo to move, also 0-254. (sync= 0xFF,servo= 0x00-0xFE,position= 0x00-0xFE)
If you can help / let me know how to modify dterm I would really appreciate it!!
Although I'm still not sure how I'm going to access this from the Android Application layer - making calculations from accelerometer & GPS, then sending the calculated servo movement down to a kernel app?
Any help in this area would be greatly appreciated!
spiritplumber said:
Controlling servos via G1 is very painless and easy, I already do that, let me know if you want tips.T
Click to expand...
Click to collapse
I would find any tips interesting !!!
Thanks again for your comments & help, you're making this project far easier than I could have hoped!!!!! hopefully I will be able offer you help in my areas of expertise some day!
- I'm an application developer by day, using VB.net/Sybase Powerbuilder/Pocketbuilder/SQL/Microsoft-based network admin.
Just a quick final question (for today!!) - my Wlan seems to have been knocked out by your kernel image... the android manager can see AP's but always reports that it was unsuccessful when trying to connect.. and ideas?
- I'm on JF1.51 ADP1, no other mods or changes.
Andy

system call -> SOFTAP on -> infrastructure mode

Hello,
Has anyone taken a look at the bcm4329's kernel module? I've been looking around and trying to figure out how the Sprint Hotspot application works and I've found it calls the SIOCSIWPRIV system call on the interface to bring up this mode.
Does anyone have any experience on this matter? I'm looking to get infrastructure mode working.
My current approach is to write a native C app, do the ioctl with some sort of struct (I'm tempted just to memalloc and hand-write the first one), and see what happens.
The driver throws a bunch of debug info into the kernel log when you invoke the command so its dead easy to spot.
Any suggestions?
andrew500 said:
Hello,
Has anyone taken a look at the bcm4329's kernel module? I've been looking around and trying to figure out how the Sprint Hotspot application works and I've found it calls the SIOCSIWPRIV system call on the interface to bring up this mode.
Does anyone have any experience on this matter? I'm looking to get infrastructure mode working.
My current approach is to write a native C app, do the ioctl with some sort of struct (I'm tempted just to memalloc and hand-write the first one), and see what happens.
The driver throws a bunch of debug info into the kernel log when you invoke the command so its dead easy to spot.
Any suggestions?
Click to expand...
Click to collapse
im definitely not up to speed on this but if you wanna post some links to the source files you're referencing, it might help me and anybody else who is interested to get up to speed quicker and provide suggestions.
appreciate your work on troubleshooting and experimenting with wifi tether!
joeykrim,
I'm knee deep in it right now. I'm taking the source code to iwconfig and using it as a template to implement the system calls I need, using a hybrid of the structs in wireless.h and in the bcm4329 driver source, from the bravo kernel. Basically I create a big struct in memory and pass it into the driver using a pointer to a iw_point struct, which holds my big master struct, and then the driver copies it out of user-space into kernel space and acts upon it.
I'll put together all the details once they are a little more solid.
It looks like infrastructure-mode on the EVO is a very distinct possibility, this code will also translate into the workaround for built-in tether on Froyo, from what I've seen they are exclusively using this broadcom interface so far.
It's a hardware specific hack, but many of the phones that have come out lately are using the bcm4329 (and with good reason, chip has freakin everything).

[Q] Android USB Programming: How to handle VID/PID's, etc.?

(I would have posted this in the development forums but apparently I don't yet have enough "karma" or something {grin})
I'm on a project to use Android tablets to exchange data via USB with an embedded microcontroller environment. At present I'm using a Nexus 7 (because it supports USB Accessory mode, so it can be powered by the other end) and an Arduino Due (because it has two USB interfaces). I've read countless articles and scoured everything I can find on the topic of programming for USB, but still have some fundamental questions.
The biggest one concerns how the host and device interfaces "identify" each other. Seems like each end needs to expose a USB interface with VID/PID values that the other end knows about and looks for during initialization. This implies that the code on each end would need to control the PID and VID values, as well as other USB descriptor values. Yet none of the code examples I've found ever discuss this.
Example: I've found that the Nexus 7 exposes one PID value (0x4E42) when its USB port is configured in "media device (MTP)" mode, and a different PID value (0x4E44) when its USB port is configured in "camera (PTP)" mode. The protocols for interacting with these two configurations is different, and the code on the other end of the wire needs to know how to handle that. I haven't checked yet but I suspect the values in the usb_interface and usb_interface_descriptor structures also change along with the PID value, since usb.org defines a whole bunch of standardized values for various device types. A connecting device would retrieve these values, potentially from multiple exposed logical interfaces on the same physical USB port, and select a compatible one.
Since I'm writing the code on both ends of the wire, doesn't my code need to somehow convey these values into the USB interface hardware? How is that done, for example, under Android? Do the code examples just omit this because everyone but me knows how to do it?
If I just "ignore" this question, then when the Arduino (acting as USB Host) polls the Nexus 7 it will have to select from whatever interfaces are offered. So... whose code is in charge of those interfaces? How does my code tell the Android OS which of these "default" interfaces it will be handling? My suspicion is that, if a USB interface is being advertised, there is *already* code behind it. That brings me full circle to the question of "How does my code inform Android that it wants to use certain VID/PID values?"
I hope I've explained this clearly. It's a pretty detailed question, so if it's unclear I can try to ask it differently. Thanks in advance for any guidance, tips, RTFM's, etc.!
For interacting arduino with android device, it can be written under eclipse, you can learned it from "Beginning Android ADK with Arduino" which can be downloaded from torrent market. VID/PID mostly used to allow your device to be recognised to your computer.
koklimabc said:
For interacting arduino with android device, it can be written under eclipse, you can learned it from "Beginning Android ADK with Arduino" which can be downloaded from torrent market.
Click to expand...
Click to collapse
Thanks, I'll look for that reference!
VID/PID mostly used to allow your device to be recognised to your computer.
Click to expand...
Click to collapse
Yes, but those parameters (along with a couple of others) are used to 1) confirm that the two devices recognize each other, and 2) in some cases to launch the proper code to handle that interface/protocol. So you must have control over them, and must initialize the USB system with the proper values in some manner. I presumed it would be in the Android API but I can't find any reference to setting the low-level values for USB connections.
Thanks again for the response! Anyone with additional data? It would be greatly appreciated!

Fly-OS Development

We're yet to choose a License so treat is a GPL v3 code right now (this is subject to change)
But we've got Fly-OS under massive development.
My Github is CakeWafflez (I can't post links yet...)
My Skype: CakeWafflez
Currently we have a serial driver, bare memory manager, a IDT table setup and a GDT setup. We're working on Paging and virtual memory addresses and debating on how we shall setup a STDIO.
At the current moment as of writing the os will not compile due to some errors in incomplete code that is being completed as we speak, specifically the keyboard driver that I am writing.
If you'd like to join in or contribute you can contact me on skype and fork the repo. For safety we're not adding anyone else into the repo at the moment.
Ok the keyboard driver is completed and we're starting to work out more memory mangment.
We're also figuring out how to handle ATA / ATAPI controllers and the floppy drive controller in order to start getting data in / out
As with that we're working on a way to send data around between functions.
The keyboard driver is broken at the moment, but it works.
Here is a bootable floppy image you can use in Vmware (Just replace the spaces with periods...)
Link: www solidfiles com/d/c1476aff59/

Rooting the Anki Vector Robot - a robot that runs Android

Hi,
my name is Melanie, I'm part of an effort to root the Vector robot made by Anki.
Anki has recently gone into administration, with the IP of the company winding up as collateral for an emergency loan that was never paid back.
Vector is very much dependent on the "cloud", namely, Anki's servers running on AWS. The SSL certificate for these servers is due to expire in September. There is little chance of it being renewed since the company has no funds.
A group of tech-savvy owners have got together on Discord to discuss how to help Vector survive the coming demise of his servers. They had already collected a not insignificant amount of information in the form of datasheets and observations as well as images of the internals of the robot and images of jigs Anki used during development.
I'm bringing this project to this forum because, internally, Vector is really a phone without the GSM part.
He is powered by a Qualcomm APQ8009 (Snapdragon 212), which has been paired with a combination ram/flash chip by Kingston, 04EMCP04-NL3DM627. There is also a Wifi/BLE module and a screen and 4 microphones.
The Snapdragon runs an Android boot loader and Linux kerner version 3.18.66-perf.
This is where he becomes different from a phone in that he doesn't start Zygote, but rather runs a number of daemons from systemd.
As shipped, there is no user accessible wired IO.
There are a number of wirepads on the PCB, as well as unpopulated pads for a micro USB port. When I joined the project, the serial port was already known, but while it provides a boot log, there is no getty on it.
The USB port had to this point not been successfully activated.
Since I'm a hardware person, that is where i placed my lever. I populated the USB port and started digging. Finally I found a solder pad labeled F_USB which was not even close tot he USB port, but turned out to be a boot mode pin from the CPU. Pulling it to VCC made the USB port enumerate in EDL mode. Qualcomm call it QDL or QDLoader, but it basically an interface to the ROM in the CPU, just like phones have.
From this I managed to grab a CPU ID but not much more.
Meanwhile, we reverse-engineered the phone app that comes with it and are currently writing a general purpose library to talk to Vector over BLE.
At this point, I found that I was facing a thicket of software, mostly either cracked or containing malware, or both, but very little legit options.
I see a few options to go forward on this:
- Find a software that can talk to the Snapdragon 212 to extract the current image
- Desolder the flash to extract the image via a programmer
- Desolder the CPU to access the flash's data lines without having to heat the flash, which could corrupt it
The last two options are bound to be destructive and all us owners have found a connection to their robots and are loath to sacrifice them. Also, they require a bit of investment and are, because of that, no quick wins.
I'm hoping that someone here may have the missing pieces I need to get from QDL 9008 mode to an image of the flash on my disk. We believe we have another way to flash it, not needing the USB port, but we don't have an image to try it with and flashing something like all zeroes would needlessly destroy a robot.
- Melanie
PS: I would post links but I'm too young to do so. There is a google group called "Project Victor" that has the info we have so far called anki-vector-rooting, a.k.a. Project Victor.
https://groups.google.com/forum/m/#!forum/anki-vector-rooting
You are welcome to PM links to me and I will post them as a work around.
hope the best!
Link to Project Vector
http://projectvictor.my.to/
Sent from my ocean using XDA Labs

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