make kexec guestable kernels - Android Software/Hacking General [Developers Only]

make kexec guestable kernels - Android Software/Hacking General [Developers Only]

hi all,
i'm going to support multiple android roms loading in my kernel_chooser + root_chooser project.
in few words it will be a powerful bootloader for android.
this is what it will be able to do ( many points are yet working ):
kernel loading thought kexec
boot from external devices
boot from subfolders
custom background
change android /sytem partition
change android /data partition
wipe android /cache partition
what i'm asking to you it's to make your android rom's kernel kexec-ready, applying them a kexec guest patch.
thus to make them ready to load for me.
if not i have to patch your kernel every time you modify it.
kernel_chooser and root_chooser are hosted here: https://github.com/tux-mind/tf201-dev
they are made for the asus transformer prime ( TF201 ), but they can run on any android device with your help.
i will add you to the github collaborators if you want to help.
now we are working on multiple android roms support.
thanks in advance for your time.
-- tux_mind

@tux_mind sounds like an interesting idea. So this works for all device's kernels? Once I apply the patch to my kernel source, what happens after that? I'll make sure to follow your progress, good work

HTCDreamOn said:
@tux_mind sounds like an interesting idea. So this works for all device's kernels? Once I apply the patch to my kernel source, what happens after that? I'll make sure to follow your progress, good work
Click to expand...
Click to collapse
thanks
yes, this should work for all devices, except for a little tuning of the partition with the configuration data ( /data ).
i have to make it to self-detect the /data partition.
let's say for example that you want to use it on your HTC Vision.
i have to build an host kernel by the stock one applying the host kexec patch.
than i have to build an android boot image which contains kernel_chooser as initrd and the above kernel.
this android boot image will be written to your current one though fastboot.
after that kernel_chooser will be able to load any kernel patched with the guest patch.
obviously the loaded kernel must be made for that device
it can also load a custom initrd and use a custom kernel CMDLINE.
so, after i made a HTC Vision kernel_chooser, your rom it's ready to load if you applied the guest patch to you kernel.
i can't explain well how to make you rom "bootable" because we are developing this
but if your kernel is kexec-loadable it will be supported by kernel_chooser.
i will update you in the next days
bye!

Really great idea! As it support other devices I can throw in my kernel which is a kexec one for the Motorola RAZR, because of our locked bootloader. The question is: how different are the methods to use kexec?
M.o.t.o.r.o.l.a.R.a.z.r - JBX-Kernel 0.5a - Tapatalk4

@tux_mind this'll sound really stupid but how do actually patch our kernels for this? Do I have to build kexec from here or something?

dtrail1 said:
how different are the methods to use kexec?
Click to expand...
Click to collapse
kexec it's a syscall, so it's the same on every arm device.
HTCDreamOn said:
@tux_mind this'll sound really stupid but how do actually patch our kernels for this? Do I have to build kexec from here or something?
Click to expand...
Click to collapse
there is a good explaination here:
http://forum.xda-developers.com/showthread.php?t=2104706
look at the "Compatibility patch".
for my tf201 the guest patch is this: http://git.lilstevie.geek.nz/?p=ubu...ch;h=54c2e480682afb0629f3854dfea4154f528421e5
which is almost the same...
i hope that almost all kernels have the same host/guest patch, in order to save us a lot of work.
the patch isn't need for kexec, but for hardboot kexec, thus to physically shutdown and restart the device with your kernel, from 0.
the standard kexec it's a assembly jump to 0 ( jmp 0x0 ) with the new kernel loaded in the .text section.
but the standard method don't reinitialize the devices and many other things that could rest in a undefined state.
btw, i have almost done my work.....i'm fighting the android udev which is overwriting my symlinks..
see you!

i got it!
my initial target was to remove devices created by ueventd and replace them with symlink to loop devices.
but android respawn ueventd and replaces my symlinks...
i tried to start the android ueventd, leave it running, and replace the /sbin/ueventd with a infinite sleep static program
but android dont' start at all..i can't even access via adb.
so, the "final" solution is to edit the /fstab.$hardware, which should be in any andoird boot image ( right ? ).
please feel free to suggest any other way to hack the mount process.
you can find the sources here: https://github.com/tux-mind/tf201-dev/tree/master/android_chooser
the program read the paths from kernel cmdline.
the syntax is that:
Code:
newandroid=blkdev:initrd_path:fstab_path
where
blkdev is the linux name of the blockdevice containing the next args ( e.g. /dev/mmcblk0p8 )
initrd_path is the path on the previous blockdevice of the android initrd ( gzipped or not )
fstab_path is the path on the previous blockdevice of the fstab file
the fstab file have this syntax:
Code:
/android/mountpoint /path/to/image/file
where
/android/mountpoint is the android mountpoint to overwrite ( e.g. /system )
/path/to/image/file is the path to the filesystem image file ( on blkdev ) ( e.g. /boot/unrooted.img )
i don't make any documentation until i will be sure that there is no better way to do this.
thanks in advance for your testing
ah, some other useful info.
because we are in testing the program write a log file with some debug info in the root of your blkdev.
so you will find /android_chooser.log on your blkdev with these info in case of errors.
tux_mind

Please
dtrail1 said:
Really great idea! As it support other devices I can throw in my kernel which is a kexec one for the Motorola RAZR, because of our locked bootloader. The question is: how different are the methods to use kexec?
M.o.t.o.r.o.l.a.R.a.z.r - JBX-Kernel 0.5a - Tapatalk4
Click to expand...
Click to collapse
Dtrail could you explain me kexec and its components required for loading new kernel because my device(electrify 2) is similar to droid razr. Using bmm kexec is boot able because I had checked by flashing droid razr's kernel which gave a boot loop.
I would be pleased and thankful to you if you help me.

Related

[DEV] Trying a new direction for unlocking bootloader

target:
loading kernel from SD card
papers:
http://processors.wiki.ti.com/index.php/Optimize_Linux_Boot_Time#Use-case_1:_Boot_from_SDHC_Card
sources:
http://arago-project.org/git/projec...;h=refs/heads/qb_v2010.06_OMAPPSP_04.02.00.07
how - general idea:
finding a way to change U-boot config to load kernel from SDHC and not from NAND.
relevant commits:
1.
omap3evm: quickboot: Config file for boot from MMC
This patch adds the minimal config to boot from MMC only.
http://arago-project.org/git/projec...it;h=20d00835c403857268feacbd23339226b834aeae
2.
ti816x: Support for boot script for setting ENV
This patch enables support for executing a script stored in MMC/SD card
to set ENV variables.This is necessary for systems which have no flash storage
and ENV needs to be set without rebuilding U-Boot binary with hardcoded values.
To generate the script named boot.scr create a file boot.txt with the normal
U-Boot commands for setting ENV. Eg: setenv bootcmd 'dhcp; tftp; bootm'
Then use mkimage utility (./u-boot/tools/mkimage) in the following manner:
mkimage -A arm -O linux -C none -name script -d boot.txt boot.scr
Copy this file to the FAT partition on the MMC/SD card and let the system boot.
Note: The script will be executed automatically in case there is no flash storage
or if nothing has been saved to the ENV section of the flash.
http://arago-project.org/git/projec...it;h=0befaf9511ec2908161c634172a0061fb8547c82

Wow! Developers are seriously taking unlocking motorola defy

So you are trying to do this or is this a guide for developers?

we need to know how to make a 2nd boot. I've asked a few times, but nobody seems to know how to configure 2nd boot in BootMenu. Also, the prototype board "BeagleBoard" has the same processor, and its a good start because a lot of software and info is available for that.

Jefgenowitsch said:
So you are trying to do this or is this a guide for developers?
Click to expand...
Click to collapse
Both
Yet I don't have much knowledge about defy boot process as top defy devs like Quarx EP3 & maniac & Koreans

Contact tom3q https://github.com/tom3q he developes new kernel for spica and loads dev kernels with kexec i am sure he will gladly help.
Sent from my MB525 using XDA App

As far as I know if you try to boot kernel from sdcard it still needs to be signed, and about 2ndboot, although it's possible to boot another kernel the devs haven't been successful to boot baseband kernel, and I don't know if they have done any more progress so far...

good idea but...
I'm thinking about a bootable mini-sd card for a while now, but not only for motorala (and I don't own one).
The idea is a universal bootable mini-sd to rescue brick tablets or phone. When you start device, it automatically force to boot from the mini-sd.
For this, we have to get on the mini-sd card:
- u-boot bootlaoder on mini-sd based on generic arm
- generic arm kernel
- busybox
- tool to flash any NAND or intenral mini-sd hdd form the rescue mini-sd to the device memory.
- a tty to use tools.
I know it's possible, but I'm not so far familiar in crosstools to build kernel and u-boot. Ask me anything about linux or grub... that's OK, but for u-boot....
I'm the happy owner of an Aishuo and a Dreambook tablets, the first boot from mini-sd internal card, the second from NAND, both with u-boot, both are bricked (mea cilpa, mea culpa, mea culpa), you see know why I explore tis idea....

people it's really better than waiting for moto to unlock it.
i think the whole xda members will be so thankfull if anyone can do it.

vick33 said:
Contact tom3q https://github.com/tom3q he developes new kernel for spica and loads dev kernels with kexec i am sure he will gladly help.
Sent from my MB525 using XDA App
Click to expand...
Click to collapse
Vick33 tom3q developed a 3d driver for the Spica I don't think he can help in this
Nice to see another Spica user
Sent from my MB525 using XDA App

Now he is developing a new kernel. There is a video on youtube when he is loading a new 2.6.38 kernel with kexec
Sent from my MB525 using XDA App

mk67 said:
I'm thinking about a bootable mini-sd card for a while now, but not only for motorala (and I don't own one).
The idea is a universal bootable mini-sd to rescue brick tablets or phone. When you start device, it automatically force to boot from the mini-sd.
For this, we have to get on the mini-sd card:
- u-boot bootlaoder on mini-sd based on generic arm
- generic arm kernel
- busybox
- tool to flash any NAND or intenral mini-sd hdd form the rescue mini-sd to the device memory.
- a tty to use tools.
I know it's possible, but I'm not so far familiar in crosstools to build kernel and u-boot. Ask me anything about linux or grub... that's OK, but for u-boot....
I'm the happy owner of an Aishuo and a Dreambook tablets, the first boot from mini-sd internal card, the second from NAND, both with u-boot, both are bricked (mea cilpa, mea culpa, mea culpa), you see know why I explore tis idea....
Click to expand...
Click to collapse
Hi!
Have you already seen this?
https://www.droid-developers.org/wiki/How_to_load_mbmloader_from_SD_card

No, I wasn't. But I did now.
This is effectively interesting, alas, the matter is that this is a motorola signed ko. Need to find other 2ndboot_mmc_usb.ko from other kernel. Generally, most of china tablets or else can already boot from external sdcard for their updates, there may be a way to explore.
I don't usually hack, but many know here.
I don't want to polute motoral dedicated threads, so I'm going to open a new one in general devel one.
I have to meditate seriously the exact goal of the idea before that, but I continue to think this is a serious interesting way for a king of universal boot system, at least, for boot device to finally root them.

bumpty bumpty bump

yes, any news?

[PATCHES] Kexec syscall support, boots kernels from SD or USB (11/6/11, GB support)

11/6/11 Update: Added statically-linked kexec to kexec_patches.tar.gz and example update.zips. Now works in stock recovery and CM7 CWM (with a kexec-patched kernel).
10/19/11 Update: Added patches for the recently released GB sources to kexec_patches.tar.gz.
Attached is a set of patches (kexec_patches.tar.gz) against EC05, and the recently released GB sources, to implement kexec syscall support in the Epic's kernel. kexec enables the booting of kernels "directly" from the SD card or over USB without having to flash them to the device first. This allows us to easily use, test, and switch between many kernels, not just the one (two with recovery) there's room for on flash.
When used in conjuction with modified init.rc scripts, this allows entire ROMs (with their own kernels) to run from SD card. In short, this allows us to run custom-kernel ROMs (e.g,. CyanogenMod) alongside each other or a stock kernel without having to flash back and forth.
Also attached is a modified version of the kexec userspace tool (also in kexec_patches.tar.gz, along with source and patches) that facilitates the proces of loading and kexecing a kernel image. Finally, attached is a demo EC05 kernel with kexec enabled (demo_kernel.tar.gz; mostly stock: RFS support only, testkeys recovery w/adbd, but does inlcude the keyboard patches), example update.zips that kexec an SD-card kernel from recovery--either as a normal boot (boot_zImage.zip) or recovery boot (boot_zImage_recovery.zip), and a script (patch_decomp_cachebufram.sh) to binary patch unmodified kernels to kexec boot faster.
Note, this thread is primarilly intended for kernel developers. Kexec probably won't be of great utility to end users until commonly-used kernels are patched. Also, although stock kernels can be kexec'd, they need some init.rc modifications boot an entire ROM from SD card. Hopefully the fine folks here will come up with a user-friendly implementation of this work that's easy for everyone to use.
Instructions:
Flash a kexec-enabled kernel (e.g., the attached demo kernel) to either /dev/block/bml7 or /dev/block/bml8. For testing purposes, this kernel needs either "ro.secure=0" or "ro.debuggable=1" set in default.prop, and also needs recovery.rc/fota.rc modified to spawn the adbd service, so that an adb root shell is available while in recovery. Also copy the attached kexec tool to a convenient location on the device (e.g., /data/local/tmp/kexec).
Reboot into recovery. If the kexec kernel is installed to bml7, run "adb reboot recovery" while the phone is running. If installed to bml8, power down and boot into recovery by holding the volume-down, camera, and power buttons.
Make sure adb is running as root. If it's not, try running "adb root".
Find the kernel (zImage) you wish to boot. These can be extracted from a kernel update.zip or Odin .tar file, or use the demo kernel again.
Push the zImage into RAM (tmpfs) with:
Code:
adb push zImage /tmp
Now, open an adb root shell with "adb shell" and run the commands:
Code:
mount -ro remount /dev/block/stl6 /mnt/.lfs
mount -ro remount /dev/block/stl9 /system
mount -ro remount /dev/block/stl10 /data
mount -ro remount /dev/block/stl11 /cache
/data/local/tmp/kexec --load-hardboot --mem-min=0x50000000 --append="console=ttySAC2,115200 loglevel=4" /tmp/zImage
sync
/data/local/tmp/kexec -e
after which the phone will reboot, show the SAMSUNG logo, and eventually boot the kexec'd kernel. Do note that when booting unmodified kernels (see below), the SAMSUNG logo will persist for ~30 seconds longer than usual.
Also note that kexec performs an "abrupt" reboot, i.e., it doesn't shutdown the system normally. Hence it's important to kexec from recovery where few services are running. It's also prudent to remount file systems read-only and sync them to avoid any potential (although unlikely) of corruption.
In the future, kexec could be better integrated into the Android framework to allow for a clean shutdown. Otherwise, probably the best way to deploy kexec is through an update.zip file that boots a kernel from the SD card. See the attached example update.zips.
Technical details:
kexec is feature of Linux that allows it to directly execute (boot) a new kernel in place of itself, allowing Linux to effectively serve as its own bootloader.
The kexec procedure is two step. The first "kexec" command loads a zImage from disk, constructs parameters (e.g., the kernel command line), and stages it in memory, after which Linux continues to run as normal. The second "kexec" command tells Linux to execute (boot) the staged kernel.
In the standard implementation, Linux "soft boots" kexec'd kernels. That is, on "kexec -e" the running instance of Linux shuts-down all devices, drivers, and goes through the process of unloading itself as it does during a normal reboot. However, instead of invoking a hardware reboot, Linux, at the final stage of unloading itself, jumps to start executing the new kernel.
This soft boot process requires that Linux hardware drivers are fully capable of unloading, reloading, and reinitializing the associated hardware without hardware-reboot or bootloader assistance. Since, for many built-in drivers, this capability is only used by kexec, hardware is often left in an unexpected or unknown state on unload, and thus the kexec'd kernel hangs on boot. Unfortunately this is the case with the Epic kernel, and soft booting doesn't work.
To work around this, the attached patches implement a "hard boot" method for kexecing kernels. Here, we use kexec to stage a kernel in memory as usual. On "kexec -e", Linux shuts-down as before, and at the very end of the unloading process it does two things: (i) scribble some information on how to boot the kexec'd kernel to a "special place" in memory, and (ii) performs a hardware reboot, invoking the Epic bootloader as a normal reboot does.
On reboot, the bootloader loads the (previously-running) bml7 or bml8 kernel and starts executing it. Here, the hardboot patch modifies the Linux the zImage decompressor code to check the "special place" in memory to see if we're actually kexecing a different kernel. If so, it switches over to the other kernel, already staged elsewhere in memory.
Known Issues:
Kernel Command Line:
Kexec (via hardboot) can boot stock or non-kexec-modified custom kernels. However, unless the copy_atags patch is applied, they can only use the kernel command line provided by the bootloader, as opposed to the custom command line provided by kexec. Although this isn't a problem when kexecing from a bml7 boot kernel, kexecing from a bml8 kernel runs recovery (fota.rc) instead of a normal boot (init.rc).
With the copy_atags patch, the command line for the kexec'd kernel must be provided by with kexec's --append option. These are the command lines provided by the bootloader in normal boot and recovery scenarios, any of which may be used:
Code:
Normal boot (init.rc):
console=ttySAC2,115200 loglevel=4
"adb reboot recovery" (recovery.rc):
bootmode=2 console=ttySAC2,115200 loglevel=4
Three-finger recovery boot (fota.rc):
bootmode=3 console=ttySAC2,115200 loglevel=4
Slow Booting:
Kexec booting of a stock or non-kexec-modified custom kernel is known take significantly longer than a regular boot, sitting at the SAMSUNG logo for 35 seconds instead of 8. The decomp_cachebufram patch resolves this issue for modified kernels. In addition, the attached patch_decomp_cachebufram.sh script will binary patch the decompressor code for any (to my knowledge) Epic kernel.
Many more details on the patches themselves are in the accompanying READMEs.
Mirror links:
Kernel & kexec-tools patches: kexec_patches.tar.gz
Kexec EC05 demonstration kernel: demo_kernel.tar.gz
Recovery script to boot /sdcard/zImage (normal boot): boot_zImage.zip
Recovery script to boot /sdcard/zImage (recovery boot): boot_zImage_recovery.zip
Script to binary patch decompressor code: patch_decomp_cachebufram.sh

Is this different in function than rodderik's dual boot support?
I know his didn't include usb booting support, but sdcard booting appears to be the same...although this seems a little cleaner, possibly
Sent from my SPH-D700 using xda premium

squshy 7 said:
Is this different in function than rodderik's dual boot support?
I know his didn't include usb booting support, but sdcard booting appears to be the same...although this seems a little cleaner, possibly
Sent from my SPH-D700 using xda premium
Click to expand...
Click to collapse
His uses a modified init, which then choses to load which init.rc, the one names init.rc.sdcard or normal init.rc. This (kexec method) reminds me A LOT like how they ran linux/android on winmo devices...it shuts down android and then runs the kernel they want (if I read correctly).

squshy 7 said:
Is this different in function than rodderik's dual boot support?
I know his didn't include usb booting support, but sdcard booting appears to be the same...although this seems a little cleaner, possibly
Sent from my SPH-D700 using xda premium
Click to expand...
Click to collapse
Yes. The genocide implementation allows a ROM to boot from the sd card as long as the kernel on the main ROM supports the sd ROM. this means you cannot dual boot a gingerbread and a froyo ROM because the need different kernels .
With this patch that limitation is removed as the sd based ROM can use its own separate kernel. This you may run stock ec05 and keep cyanogen or a gingerbread on the sd card to test and play with.
Great work mkasick
Sent from my SPH-D700 using Tapatalk

I was never interested in the dual boot feature since that was ROM's only and itwas limited by kernel support.
But now this really interest me, can't wait till we see some developers take advantage of this.
Sent from my SPH-D700 using xda premium

All I have to say is hope you stick with the epic your amazing
Sent from my SPH-D700 using Tapatalk

Yes, this is complementary to Rodderik's dual boot. Kexec allows one to load a different kernel, but it still defaults to booting the ROM stored in flash. Which is great for kernel testing, but not of much use otherwise.
It's easy enough to modify a kernel to load a ROM only from SD, but then we'll start seeing a divide between "bml kernels" and "SD kernels", when really it'd be nice to have init scripts that support both. That's where Rodderik's work comes in.
Probably the best is to have a kernel command line parameter that specifies where the ROM is located, so it can be passed in. Something like "console=ttySAC2,115200 loglevel=4 systemfs=mmcblk0p2 datafs=mmcblk0p3 cachefs=mmcblk0p4". These would default to stl9, stl10, stl11 respectively if unspecified. The kernel command line is available to init through "/proc/cmdline", and it's easy enough to parse in a shell script.
But yes, keeping a working ROM on flash while testing/debugging CyanogenMod was my primary motivation, since I need a working phone "during the day" and can't touch CyanogenMod otherwise.
formula84 said:
All I have to say is hope you stick with the epic your amazing
Click to expand...
Click to collapse
Thanks!
I'm much of a year out on a full upgrade, and I'm not considering a new device sooner as long as my Epic still works.
Edit: An obvoius limitation is modem compatibility. I've avoided the GB leaks thus far, so I'm not sure what's the status with that. But if GB supports the EC05 modem, then you can dual boot EC05 and GB-whatever. Same if EC05 supports newer modems.
Speaking of which, anyone know what GB modem compatibilty is like?

mkasick said:
Yes, this is complementary to Rodderik's dual boot. Kexec allows one to load a different kernel, but it still defaults to booting the ROM stored in flash. Which is great for kernel testing, but not of much use otherwise.
It's easy enough to modify a kernel to load a ROM only from SD, but then we'll start seeing a divide between "bml kernels" and "SD kernels", when really it'd be nice to have init scripts that support both. That's where Rodderik's work comes in.
Probably the best is to have a kernel command line parameter that specifies where the ROM is located, so it can be passed in. Something like "console=ttySAC2,115200 loglevel=4 systemfs=mmcblk0p2 datafs=mmcblk0p3 cachefs=mmcblk0p4". These would default to stl9, stl10, stl11 respectively if unspecified. The kernel command line is available to init through "/proc/cmdline", and it's easy enough to parse in a shell script.
But yes, keeping a working ROM on flash while testing/debugging CyanogenMod was my primary motivation, since I need a working phone "during the day" and can't touch CyanogenMod otherwise.
Thanks!
I'm much of a year out on a full upgrade, and I'm not considering a new device sooner as long as my Epic still works.
Edit: An obvoius limitation is modem compatibility. I've avoided the GB leaks thus far, so I'm not sure what's the status with that. But if GB supports the EC05 modem, then you can dual boot EC05 and GB-whatever. Same if EC05 supports newer modems.
Speaking of which, anyone know what GB modem compatibilty is like?
Click to expand...
Click to collapse
As far as I know, and from experience, modems are a free for all except for bonsai. Ec05 modem works on gb, leaked modems work on ec05.

this is definitely very cool, thanks mkasick!
Sent from my SPH-D700 using XDA Premium App

mkasick you never cease to amaze me...i'll definately play with this, this week if i have the time!

Rodderik said:
mkasick you never cease to amaze me...i'll definately play with this, this week if i have the time!
Click to expand...
Click to collapse
Great!
If you run into something not particularly straight forward, or think there's something I can clarify, please ask. I've been playing around with this long enough that I fear I might've overlooked documenting a detail or two that would be helpful for others.

So to patch any kernel u just point the script to the zImage?
sent from my epic 4g. with the key skips.

ugothakd said:
So to patch any kernel u just point the script to the zImage?
Click to expand...
Click to collapse
The script only implements one patch, it allows any kernel to boot ~30 seconds faster when kexec'd.
But yes, "./patch_decomp_cachebufram.sh zImage" modifies that zImage to boot faster. It requires the xxd hexdump tool that's packaged with vim.
Kexec support itself, along with the slew of other source patches, has to be applied to a kernel source tree, from which a new kernel must be built to take advantage of them.

mkasick said:
The script only implements one patch, it allows any kernel to boot ~30 seconds faster when kexec'd.
But yes, "./patch_decomp_cachebufram.sh zImage" modifies that zImage to boot faster. It requires the xxd hexdump tool that's packaged with vim.
Kexec support itself, along with the slew of other source patches, has to be applied to a kernel source tree, from which a new kernel must be built to take advantage of them.
Click to expand...
Click to collapse
I see...so its a no-go for gb. Or at least quick gingerbread.
sent from my epic 4g. with the key skips.

ugothakd said:
I see...so its a no-go for gb. Or at least quick gingerbread.
Click to expand...
Click to collapse
You should be able to kexec a GB kernel, but you'd need an EC05-ish /system on flash to boot recovery. Unless GB recovery is compatible with Froyo kernels.
If you're going to boot a GB kernel, you'd probably want to repackage the initramfs with an init.rc that loads the rest of the GB ROM off SD. It's actually not a bad way to keep EC05 around for a stable, working phone, and to test GB leaks as they happen. Which, hopefully, shouldn't be much longer.

wow mkasick, you never cease to amaze me bro...
I wish I wasn't working so many damned hours now, with your patches, I really want the dual boot now. Like you, the need for a working phone at all times is what keeps me from flashing more ROMs, including EpicCM and the gb leaks...
I hope Rodderik figures this out pretty quickly, as most of my dev time is spent on the IRC channels, and he's usually around to help and answer questions.
Once I can get my Clean Kernel working with this, I'll be stoked... I have had a tough time dealing with patches thus far, I usually git cherry-pick and/or manually edit, so I need to figure out how to use the patches correctly.
Anyways, gotta go to work now (I'm working 50+ hour weeks now, hence the time constraints), but hopefully I can get the time to get it into my kernel.
Thanks, mkasick!
Sent from my Samsung Epic4G

DRockstar said:
I have had a tough time dealing with patches thus far, I usually git cherry-pick and/or manually edit, so I need to figure out how to use the patches correctly.
Click to expand...
Click to collapse
What environment (OS, etc.) are you using? Is the "patch" utility working for you?
The patches are split up based on functionality. In each patch directory there's a "series" file that lists the order they should be applied. There's a program, quilt that can help manage them but it's not necessary. If you're running a bourne shell (e.g., bash) in the "Kernel" directory of the kernel sources, you should be able to apply the patches with:
Code:
while read i; do patch -p 1 < "/path/to/kexec_patches/kernel-EC05/$i"; done < "/path/to/kexec_patches/kernel-EC05/series"
Whether they'll apply cleanly or not is a different story, but that's the general idea.
And yeah, time ....

Thank you mkasick, that's a great explanation, I think I can handle that, much appreciated!
For the record, I compile by ssh into dev boxes donated for dev use. They all run linux in different distros. I find this most convenient since I can do most everything from the command line using your brilliant connectbot for epic
Sent from my Samsung Epic4G

With those recovery scripts, doesn't Clockwork Mod have to have kexec set up?

ugothakd said:
With those recovery scripts, doesn't Clockwork Mod have to have kexec set up?
Click to expand...
Click to collapse
You mean for boot_zImage_recovery.zip to work?
The CWM kernel doesn't need full kexec support in order to be booted via kexec. But it does need the copy_atags patch in order to respect the "bootmode=3" kernel argument.
Actually, you can take any existing Epic kernel and somewhat-easily fix it to be bootable via kexec. Steps are:
1. Extract EC05 kernel sources. Or use the GB sources, it doesn't matter, it doesn't even have to match the version of the kernel you're fixing.
2. Apply "decomp_cachebufram" and "decomp_copy_atags" patches.
3. Build a kernel. Config options don't matter much since this kernel is going to be thrown away.
4. Find the zImage for the kernel you want to fix. Run:
Code:
skip=`grep -Fabom 1 $'\x1f\x8b\x08' zImage | head -n 1 | cut -d : -f 1`
dd if=zImage bs=1 skip="$skip" | gunzip > Image
cp Image arch/arm/boot/Image
which extracts the decompressed kernel payload from the zImage, and replaces the "Image" that was previously built with the one you've extracted.
5. Run "make" in the kernel source directory again. You might have to append a "CROSS_COMPILE=" path to match the one used in a build script. The output should be:
Code:
CHK include/linux/version.h
make[1]: `include/asm-arm/mach-types.h' is up to date.
CHK include/linux/utsrelease.h
SYMLINK include/asm -> include/asm-arm
CALL scripts/checksyscalls.sh
CHK include/linux/compile.h
Kernel: arch/arm/boot/Image is ready
GZIP arch/arm/boot/compressed/piggy.gz
AS arch/arm/boot/compressed/piggy.o
LD arch/arm/boot/compressed/vmlinux
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
Building modules, stage 2.
MODPOST 13 modules
which shows that the build process took the existing, extracted Image, compressed it, and attached a new kexec-compatible decompressor to it.
The resulting "arch/arm/boot/zImage" can be kexec'd, and command line arguments should be respected, e.g., if you want to boot into CWM recovery.

[Q] GT-I9000M kernel compiling

I've got this side project going where I've decided to try to modify the stock kernel for my GT-I9000M.
I'm a Gentoo linux user and have cross-compiled kernels for embedded systems with or without initramfs and modules successfully many times. Rather than just grab and flash the latest mod from the net I want to understand exactly how to create my own.
I already have access via a chroot to a working Gentoo install, however that runs in a sandbox inside android userland, which can be irritating to say the least. I'm already able to create binaries for armv7a on the phone itself, which is a time and power-consuming novelty.
I setup a development environment on my main computer and made sure I could create working binaries for the armv7a.
I backed up all the bml partitions on my phone.
Next, I made sure I could access Download Mode and experimented with Heimdall until I was satisfied I was able to recover from any bad kernel flashes.
I altered the first boot logo in param.lfs with dd, but that's a whole other story.
Next, I downloaded Samsung's source for Froyo and followed the instructions to create a zImage.
aries_eur_defconfig selects the FM radio module and the Samsung TV out driver which are broken. No problem, I figured I could check that out later so I disabled those options for now. it compiles! great! But it didn't boot. I turned to the internet for ways to solve the problem.
There was a lot of conflicting information. I ended up trying a lot of different approaches, modules, firmware, version info, kernel command lines, fbcon... well I messed around.
Some time later, I find myself happily booting with my own kernel. The bootloader displayed my custom logo in param.lfs, but fbcon didn't work and I got a stock samsung gt-i9000 logo before android booted up! The phone worked, wifi worked, bluetooth worked, it was awesome (for 2.6.32.9 that is )!
So, great! Except I got overconfident and cocky. I made a slew of changes trying to get fbcon to work and to top off the evening I overwrote my working zImage with a broken kernel (without a backup of my working custom zImage or .config). I still have backups otherwise of course and haven't lost the functionality of my phone in any way, but now I'm just irritated.
Anybody else working on compiling from source on the GT-I9000M?

I pressed ahead and tried to recreate the conditions that got me a working kernel and as of yet I've been unsuccessful Luckily I've got a kmsg from the kernel when it booted. I can see the kernel command line on the custom kernel that booted was simply "console=ttySAC2,115200" although I do recall trying different values for init= ... The default init in the sources is /linuxrc which doesn't exist in initramfs.
There are also settings for the kernel command line and version information in arch/arm/mach-s5pv210/include/mach/param.h
Is there a known good method to compile from Samsung's sources?

I unpacked a known good zImage, played with it's initramfs, repacked it and it boots just fine.
I've tried again with a fresh copy of the gt-i9000 froyo-samsung branch:
- unpack initramfs from a known good 2.6.32.9 kernel
- make clean
- make aries_eur_defconfig
- make menuconfig, add initramfs, remove Samsung TV driver and FM radio module
- make
the resulting vmlinux is: ELF 32-bit LSB executable, ARM, version 1 (SYSV), statically linked, not stripped (I know, it's zImage not vmlinux but I'm just doing sanity checks)
I have a custom logo in param.lfs which always displays on boot. A second logo is compiled into the kernel, and I do see a change in the logo when my kernel boots (it shows GT-I9000 instead of GT-I9000M after the first logo). This leads me to believe that the kernel is booting... but the phone powers off after booting.
I've tried the recommended changes to default.prop to use adb to obtain the kmsg of the new kernel. This has not worked however, which could mean that the kernel doesn't get as far as initramfs.
the kernel command line from the kmsg I have from the one time that a custom kernel of mine booted is simply: "console=ttySAC2,115200 loglevel=4" . There's no mention of init, which I think should be init=/init although aries_eur_defconfig seems to think that init=/linuxrc is appropriate (linuxrc doesn't exist?) Regardless, it doesn't seem to matter what I specify for init.
Which leaves proprietary Samsung kernel modules. If they can't load, this could explain everything I'm experiencing. It isn't clear what specific version the proprietary modules are expecting.

Maybe this will help somebody else. I've got it working now.
Attached is my working config.

Kexec-hardboot patch

In this post, I would like to explain what kexec-hardboot patch is and also bring it to light a bit more since until now, it was only burried in MultiROM thread.
@kernel developers: I would like to ask you to merge this patch to your kernels, because it is essential part of MultiROM - it allows me to boot any kernel without changing the boot partition. I realize that it is no small request, but the patch is not big, touches relatively stable parts of kernel and should not cause any problems. Thank you.
What is kexec?
It is syscall of Linux kernel, which allows you to boot another Linux kernel without restarting the device - "Linux boots itself". The functionality is equivalent to fastboot -c *cmdline* boot zImage initrd.img, but without PC and fastboot. It is fairly known thing, so more info at wikipedia and man kexec.
Standard kexec call unfortunatelly does not work on Nexus 7. It freezes somewhere, and it is very difficult to find out where - probably some of the drivers are not shut down/re-initialized properly, it is a commong thing among Android devices, which is why kexec-hardboot was made.
What is the difference between normal and hardboot exec?
Kexec-hardboot patch adds a real device restart to that process, so that all the drivers can be properly reinitialized. It stores new kernel to RAM, reboots the device as usual, and kernel from boot partition immediately jumps to the one which was stored to RAM before reboot.
Another difference is that both kernels must be patched. The "host" kernel requires a full patch, the one which is being kexecd' requires only two small compatibility patches.
To sumarize the process:
kexec --load-hardboot.... is called and kernel it loaded into RAM.
kexec -e is called. Special info is written to memory (to area which is not overwritten on reboot) and the device is rebooted.
After reboot, very early in the boot process, kernel checks if that special info is present in RAM and if so, it loads new kernel from RAM and jumps to it.
Kexecd' kernel starts and boots.
For more info, read the original thread.
Patches:
Full kernel patch: https://gist.github.com/4558647, 4.1 kernel repo, cm 10.1 kernel repo
This is the full kernel patch. Kernels with this patch can be both "host" and "guest" kernels.
Related CONFIG options:
CONFIG_KEXEC=y
CONFIG_KEXEC_HARDBOOT=y
CONFIG_ATAGS_PROC=y
CONFIG_GROUPER_HARDBOOT_RECOVERY=n
First three options must be enabled. Last one, GROUPER_HARDBOOT_RECOVERY, specifies if the kexec call should reboot to normal mode or to recovery. This can be useful if you don't have the kernel in boot partition but only as kernel in recovery partition. You usualy want to disable this option.
Compatibility patch: https://gist.github.com/4458581
This patch only makes the kernel bootable via kexec, ie. it can't be the host kernel. This was made for Ubuntu kernel (and it was accepted), because I did not want to drag the whole patch in there. If your kernel is for Android ROMs, you should use the full patch.
Userspace kexec binary: View attachment kexec-tools.zip
That ZIP file contains kexec source, patches and README. It is from the original patch from Mike Kasick. It also contains precompiled, statically linked kexec binary, so you probably just want to use that.
Usage:
Once you have the kernel patches and kexec userspace binary in place, just run following command to boot into new kernel:
Code:
kexec --load-hardboot zImage --initrd=initrd.img --mem-min=0x85000000 --command-line="$(cat /proc/cmdline)"
kexec -e
Note the command line parameter - cmdline from bootloader is not added automatically, you have to put it there by yourself.
Currently used by:
MultiROM - I use it to boot different kernels (eg. Ubuntu).
MOSLO - Part of Plasma Active for Nexus 7, also usefull tool for every N7 developer - read more: http://ruedigergad.com/2012/12/09/nexus-7-easily-flashaccess-entire-userdata-partition/
Authors:
This patch was made by Mike Kasick for Samsung Epic 4G. Since that, it was ported to several devices, one of them is Asus Transformer TF201 - I used patch from TF201 and modified it a bit (basically just changed few SoC specific constants). People at #ubuntu-arm helped me out with that, thanks.

Hi Tasssadar,
im trying to get this to work on the HOX in order to have a shot at multiboot,
the patched applied with no problem... however on compiling i gett this error
"Adress for kexec hardboot page not defined"
ask this error naturely defined to kick in with every device beside N7 i that comment completely....
and that ended up giving me an error about KEXEC_HB_PAGE_ADDR not defined,
so i readded it, but i removed the "#if defined(CONFIG_MACH_GROUPER)"
now trying to compile it, its gets pretty close to the end... but failed with unexpected string error at line OUTPUT_ARCH(arm) in file linux/arch/arm/boot/compressed/vmlinux.lds
Code:
/*
* linux/arch/arm/boot/compressed/vmlinux.lds.in
*
* Copyright (C) 2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
OUTPUT_ARCH(arm)
ENTRY(_start)
SECTIONS
{
/DISCARD/ : {
*(.ARM.exidx*)
*(.ARM.extab*)
/*
* Discard any r/w data - this produces a link error if we have any,
* which is required for PIC decompression. Local data generates
* GOTOFF relocations, which prevents it being relocated independently
* of the text/got segments.
*/
*(.data)
}
. = 0;
_text = .;
.text : {
_start = .;
*(.start)
*(.text)
*(.text.*)
*(.fixup)
*(.gnu.warning)
*(.glue_7t)
*(.glue_7)
}
.rodata : {
*(.rodata)
*(.rodata.*)
}
.piggydata : {
*(.piggydata)
}
. = ALIGN(4);
_etext = .;
.got.plt : { *(.got.plt) }
_got_start = .;
.got : { *(.got) }
_got_end = .;
_edata = .;
. = ALIGN(8);
__bss_start = .;
.bss : { *(.bss) }
_end = .;
. = ALIGN(8); /* the stack must be 64-bit aligned */
.stack : { *(.stack) }
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
.stab.exclstr 0 : { *(.stab.exclstr) }
.stab.index 0 : { *(.stab.index) }
.stab.indexstr 0 : { *(.stab.indexstr) }
.comment 0 : { *(.comment) }
}
also, im booted into windows now... so i can't provide the exact error.

I'm afraid "comment everything which doesn't work" won't work here. The KEXEC_HB_PAGE_ADDR and END_MEM is device-specific, it will most likely be different for HTC One X. You can find out what address is it supposed to be by examining /proc/iomem on your device. For example, here's memory map from grouper:
Code:
...
80000000-be9fffff : System RAM
80008000-808faba7 : Kernel text
80940000-80b8228f : Kernel data
beb00000-bebfffff : ram_console
...
So, for grouper, END_MEM is 0xbe9fffff + 1 = 0xbea00000.
KEXEC_HB_PAGE_ADDR is located 1MB before console RAM, which is in this case also immediatelly after System RAM, so for grouper, it is also 0xbea00000.
but failed with unexpected string error at line OUTPUT_ARCH(arm) in file linux/arch/arm/boot/compressed/vmlinux.lds
Click to expand...
Click to collapse
That doesn't seem to be related to this patch. Are you using correct cross-compiler?

Tasssadar said:
I'm afraid "comment everything which doesn't work" won't work here. The KEXEC_HB_PAGE_ADDR and END_MEM is device-specific, it will most likely be different for HTC One X.
Click to expand...
Click to collapse
i figured
but im walking you through what i did.
You can find out what address is it supposed to be by examining /proc/iomem on your device. For example, here's memory map from grouper:
Code:
...
80000000-be9fffff : System RAM
80008000-808faba7 : Kernel text
80940000-80b8228f : Kernel data
beb00000-bebfffff : ram_console
...
So, for grouper, END_MEM is 0xbe9fffff + 1 = 0xbea00000.
KEXEC_HB_PAGE_ADDR is located 1MB before console RAM, which is in this case also immediatelly after System RAM, so for grouper, it is also 0xbea00000.
Click to expand...
Click to collapse
Code:
7d000000-7d003fff : tegra-udc.0
7d000000-7d003fff : tegra-otg
7d000000-7d003fff : tegra-udc
7d004000-7d007fff : tegra-ehci.1
80000000-beafffff : System RAM
80008000-8094000f : Kernel text
809a8000-810b940f : Kernel data
beb00000-bebfffff : ram_console
bec00000-beffffff : fbmem
bf000000-bf7fffff : fbmem
0xbeafffff + 1 = 0xbeb00000
grrr that would put me inside the ram_console...
aaaa would it wok if i used the address before??
7d00800
Edit:
or did your ram RAM end earlier because you set you END_MEM 0xbea00000
in that case, it works out just the same with the HOX
That doesn't seem to be related to this patch. Are you using correct cross-compiler?
Click to expand...
Click to collapse
i would have guessed so, but the kernel compiled and is working before the patch.
im using the one provided by google (Android NDK r9) while it contains booth gcc 4.6/4.8 im using 4.6 (arm-linux-androideabi-)

The patch will move ram_console 1MB further, see https://gist.github.com/Tasssadar/4558647#file-n7_hardboot-diff-L387 . You'll have to modify this part of the patch, it will be in different file for your device.

Tasssadar said:
The patch will move ram_console 1MB further, see https://gist.github.com/Tasssadar/4558647#file-n7_hardboot-diff-L387 . You'll have to modify this part of the patch, it will be in different file for your device.
Click to expand...
Click to collapse
HOX is also a Tegra 3 device... so im guessing i wont need to touch a thing?
also note... that iomem provided is from an unpatched kernel (as i cant compile a patched one)
also,
im currently on freenode #htc-one-x
if you dont mind joining.

I've been looking through the kexec-hardboot patch these last few days, trying to actually understand it instead of just blindly porting it and after several hours of messing with assembler with no means to debug it, I've managed to remove the need for guest kernel to be patched. This is not really useful for grouper, since thanks to multirom and accepting kernel devs, nearly every third-party kernel has the proper patches. But, if I'll port multirom to some other device (hello, flo), it will be very useful
To know more see the changes in this commit, but you'll probably need to understand how the patch does things: https://github.com/Tasssadar/androi...mmit/2ce4130061f72430a8ddfde25346c4e528c5c30b
@mkasick: Could you please look over this? I'm afraid there's some good reason why you didn't do this in the first place, like rewriting some part of memory which shouldn't be rewritten or something like that. Thank you.

Tasssadar said:
I've been looking through the kexec-hardboot patch these last few days, trying to actually understand it instead of just blindly porting it and after several hours of messing with assembler with no means to debug it, I've managed to remove the need for guest kernel to be patched. This is not really useful for grouper, since thanks to multirom and accepting kernel devs, nearly every third-party kernel has the proper patches. But, if I'll port multirom to some other device (hello, flo), it will be very useful
To know more see the changes in this commit, but you'll probably need to understand how the patch does things: https://github.com/Tasssadar/androi...mmit/2ce4130061f72430a8ddfde25346c4e528c5c30b
@mkasick: Could you please look over this? I'm afraid there's some good reason why you didn't do this in the first place, like rewriting some part of memory which shouldn't be rewritten or something like that. Thank you.
Click to expand...
Click to collapse
Perfect timing, just finished my last exam
Edit:
Also, this applies on top of the original patch right??
Edit2:
i can't seem to get it to kexec boot, but i didn't do much testing, maybe 2morrow night!
Edit3:
fixed, it was a problem with min-addr,
changed it to 0x82000000 and it worked

One more question...
TEGRA_PMC_BASE is also device specific, ain't it???
So, for a Qualcomm device, what should I be using? I am guessing it is MSM_RPM_BASE, which I got from here: http://forum.xda-developers.com/showpost.php?p=31127486&postcount=7

Yes, it is SoC-specific. This is using some special register to reset the chip, I'm not sure if that is available on msm chips - probably yes, but in some different form. Your best chance is to examine restart sequence in arch/arm/mach-msm/restart.c and port it to assembler.

Tasssadar said:
Usage:
Once you have the kernel patches and kexec userspace binary in place, just run following command to boot into new kernel:
Code:
kexec --load-hardboot zImage --initrd=initrd.img --mem-min=0xA0000000 --command-line="$(cat /proc/cmdline)"
kexec -e
Click to expand...
Click to collapse
The address of 0xA0000000 is not necessarily the best choice going forward. It originally made perfect sense, as it is well above everything else. But now that we can boot unpatched guest kernels, we can hit the interesting situation where the guest decompression may take a full minute. At least it's when I've seen on the Ouya game console that's running the next chip after Grouper.
When I realized what's going on, I changed to 0x8E000000, as it gets me just below the 256 MB limit of cache-enabled memory that's present on a typical guest at that early decompression stage. It's enough to hold a typical 8 MB boot image kernel/ramdisk. Now the guest kernel startup is fast in all cases.
Thank you Tasssadar for continuing your work in this area, especially with finding that way to allow unpatched guests.

Indeed, that's actually what I'm using in MultiROM for flo and mako (and grouper, but it is useless 'cause not all 3rd-party kernels have been updated), I just kinda "forgot" to update these threads.

Would it work on devices with locked bootloaders (Xperias). I mean :does the idea of this patch would also work on bootloader unlock allowed :no devices?
Sent from my LT22i using xda app-developers app

I am trying to build a kexec patched kernel integrated into a ROM. I make sure that the following code is there in the defconfig:
CONFIG_KEXEC=y
CONFIG_KEXEC_HARDBOOT=y
CONFIG_ATAGS_PROC=y
The ROM works well, except that it does not boot my secondary ROMs - kexec hardboot patch missing. I have multi ROM and TWRP recovery installed
What am I missing?

Logs or it didn't happen.
Show me dmesg from normal boot into android, with MultiROM and your kernel installed.
Code:
adb shell
su
dmesg > /data/local/tmp/dmesg.txt
exit
exit
adb pull /data/local/tmp/dmesg.txt

Porting?
Tassadar which things do I need to boot kexec kernel on my device (Motorola Electrify 2) .

@Tasssadar, Sorry for picking up this kinda "old topic" but I'm sadly experiencing some problems while trying to port kexec-hardboot to the Sony Xperia Z2 (aka sirius). I applyed all needed commits (cherry-picked from a apparently working Z1 repo for stock kernel) to my CM based custom kernel (https://github.com/Myself5/android_kernel_sony_msm8974/tree/kexec-cm-12.0) and it does not boot at all. It's stuck on the Sony Logo, and it seems like I can't get any log either. I also tryed the stock cm kernel with the patch (https://github.com/Myself5/android_kernel_sony_msm8974-kexec) cause I tought it might be some incompatibility, but sadly it wasn't. Hope you have any ideas to solve my problems, cause I'm out of ideas ATM. I also checked the kexec commits for other devices (namely the One Plus One) and it seems like I got everything needed.
Thanks in Advance

Tasssadar said:
In this post, I would like to explain what kexec-hardboot patch is and also bring it to light a bit more since until now, it was only burried in MultiROM thread.
@kernel developers: I would like to ask you to merge this patch to your kernels, because it is essential part of MultiROM - it allows me to boot any kernel without changing the boot partition. I realize that it is no small request, but the patch is not big, touches relatively stable parts of kernel and should not cause any problems. Thank you.
What is kexec?
It is syscall of Linux kernel, which allows you to boot another Linux kernel without restarting the device - "Linux boots itself". The functionality is equivalent to fastboot -c *cmdline* boot zImage initrd.img, but without PC and fastboot. It is fairly known thing, so more info at wikipedia and man kexec.
Standard kexec call unfortunatelly does not work on Nexus 7. It freezes somewhere, and it is very difficult to find out where - probably some of the drivers are not shut down/re-initialized properly, it is a commong thing among Android devices, which is why kexec-hardboot was made.
What is the difference between normal and hardboot exec?
Kexec-hardboot patch adds a real device restart to that process, so that all the drivers can be properly reinitialized. It stores new kernel to RAM, reboots the device as usual, and kernel from boot partition immediately jumps to the one which was stored to RAM before reboot.
Another difference is that both kernels must be patched. The "host" kernel requires a full patch, the one which is being kexecd' requires only two small compatibility patches.
To sumarize the process:
kexec --load-hardboot.... is called and kernel it loaded into RAM.
kexec -e is called. Special info is written to memory (to area which is not overwritten on reboot) and the device is rebooted.
After reboot, very early in the boot process, kernel checks if that special info is present in RAM and if so, it loads new kernel from RAM and jumps to it.
Kexecd' kernel starts and boots.
For more info, read the original thread.
Patches:
Full kernel patch: https://gist.github.com/4558647, 4.1 kernel repo, cm 10.1 kernel repo
This is the full kernel patch. Kernels with this patch can be both "host" and "guest" kernels.
Related CONFIG options:
CONFIG_KEXEC=y
CONFIG_KEXEC_HARDBOOT=y
CONFIG_ATAGS_PROC=y
CONFIG_GROUPER_HARDBOOT_RECOVERY=n
First three options must be enabled. Last one, GROUPER_HARDBOOT_RECOVERY, specifies if the kexec call should reboot to normal mode or to recovery. This can be useful if you don't have the kernel in boot partition but only as kernel in recovery partition. You usualy want to disable this option.
Compatibility patch: https://gist.github.com/4458581
This patch only makes the kernel bootable via kexec, ie. it can't be the host kernel. This was made for Ubuntu kernel (and it was accepted), because I did not want to drag the whole patch in there. If your kernel is for Android ROMs, you should use the full patch.
Userspace kexec binary: View attachment 1653562
That ZIP file contains kexec source, patches and README. It is from the original patch from Mike Kasick. It also contains precompiled, statically linked kexec binary, so you probably just want to use that.
Usage:
Once you have the kernel patches and kexec userspace binary in place, just run following command to boot into new kernel:
Code:
kexec --load-hardboot zImage --initrd=initrd.img --mem-min=0x85000000 --command-line="$(cat /proc/cmdline)"
kexec -e
Note the command line parameter - cmdline from bootloader is not added automatically, you have to put it there by yourself.
Currently used by:
MultiROM - I use it to boot different kernels (eg. Ubuntu).
MOSLO - Part of Plasma Active for Nexus 7, also usefull tool for every N7 developer - read more: http://ruedigergad.com/2012/12/09/nexus-7-easily-flashaccess-entire-userdata-partition/
Authors:
This patch was made by Mike Kasick for Samsung Epic 4G. Since that, it was ported to several devices, one of them is Asus Transformer TF201 - I used patch from TF201 and modified it a bit (basically just changed few SoC specific constants). People at #ubuntu-arm helped me out with that, thanks.
Click to expand...
Click to collapse
I'm sorry for picking up this older topic as well, but I always played with the thought of merging kexec support into a kernel and I'm doing one right now.. But my secondary device is a LG G2 and since the era of Lollipop began, somehow MultiBoot just stopped working and nobody can figure out why. I think they even started to build some new concept now.. So before I spark a heated debated by Note 4 users I'd love to know if you have any idea if this patch is still applicable? Altough the only way to find out is to probably just try it lol.

Tasssadar said:
In this post, ....
Click to expand...
Click to collapse
Bro can you please mention on your wiki that kexec isnt supported for x64 devices? It will be great help and save developers hours! I was porting for oneplus 2 when a dev told me that kexec isnt there for x64. I was shocked
Is any alternative available for that? Please reply! Thanks.
All other devs, who cant make multirom to work (lollipop is the x64 era) stop working. Kexec isnt supported for x64. Find an alternative for it.

Can Anyone help me to port this? Here is my patched kernel (ignore arch/arm64) and this is /proc/iomem.
Code:
80000000-854fffff : System RAM
80008000-80fa43ef : Kernel code
81112000-817bf797 : Kernel data
8cb00000-9fefffff : System RAM
9ff00000-9ff3ffff : persistent_ram
9ff40000-9ff7ffff : persistent_ram
9ff80000-9fffffff : persistent_ram
a0000000-ffffefff : System RAM
For kexec_hb_page_addr the value i inseted is 85500000 coz as tasssadar said 884fffff + 1 = 85500000, but I don't know what value add for
Code:
#elif defined(CONFIG_ARCH_MSM8916)
/* Restart using the PMIC chip, see mach-msm/restart.c */
ldr r0, =MSM8916_HARDBOOT
mov r1, #0
str r1, [r0, #0]
loop: b loop
MSM8916_HARDBOOT, and if I compile the kernel it stucks on samsung logo.

[ROM][UNOFFICIAL] LineageOS 17.1 for Unihertz Atom L (20200828)

Introduction
This thread contains the LineageOS 17.1 custom firmware images for the Unihertz Atom L, a rugged Android phone released by Unihertz in July 2020, and the accompanying LineageOS Recovery used for flashing the firmware.
Please note that this ROM is one of my side projects, for which I could provide zero warranty. By installing this ROM, you acknowledge that you take all the risks that come with installing custom firmwares on your devices, including but not limited to bricking your device, losing your data, etc. You are always suggested to keep backups and make sure you know how to flash back to official ROM before trying any custom ROMs.
Please find the download links in the Download section. The following sections are guides to installing the ROM.
WARNING: DO NOT try to install this on Atom XL. This is ONLY for the Atom L.
Working Features
- All basic features (Telephony, VoLTE, Audio, Camera, NFC, WiFi, Bluetooth, ....)
- Programmable PTT (red) button (Functionality can be set in Settings - System - Buttons, under the "Search Button" section)
- 48MP camera seems to be working (unlike on many other super resolution devices)
Known Issues
- VoLTE is working (at least for me) but sometimes quirky. If you find it somehow stopped working, usually turning it off and back on again (in Settings - Network - Mobile Network) will fix it. Putting the device to SELinux Permissive mode also fixes most of the VoLTE quirks but this is not recommended (a few quirks in Enforcing mode is better than having the whole device Permissive)
Unlocking
1. Boot your Atom L to the official OS
2. Go into Settings - About phone, tap "build number" several times to enable developer settings
3. Go to Settings - System - Developer Settings, enable OEM unlocking and ADB debugging
4. Run `adb reboot bootloader` on your PC (there is no way to enter bootloader directly, only possible through adb)
5. Run `adb flashing unlock` and comfirm unlock on device (THIS WILL WIPE ALL DATA)
6. Reboot and now you should see an unlocked warning during boot screen.
Installing LineageOS Recovery
For now the only working recovery is the LineageOS Recovery, because the device's kernel does not load the touch driver in recovery mode for whatever reason, rendering TWRP useless.
1. Download `lineage_recovery_XXX.img` and `vbmeta.zip`, unpack `vbmeta.zip` to get three .img files starting with `vbmeta`
2. Run `adb reboot bootloader` to put your device in bootloader mode
3. Run `fastboot flash --disable-verification --disable-verity vbmeta vbmeta.img`
4. Run `fastboot flash --disable-verification --disable-verity vbmeta_system vbmeta_system.img`
5. Run `fastboot flash --disable-verification --disable-verity vbmeta_vendor vbmeta_vendor.img`
6. Run `fastboot flash recovery lineage_recovery_XXX.img`
7. Run `fastboot reboot recovery` to reboot into the newly-installed LineageOS Recovery
The LineageOS Recovery is operated by volume keys as selection and power as confirmation (or entering sub-menus). To return to upper levels of menus from sub-menus, press volume up until the selection goes to the first item and then disappears, then press power (i.e. there's a hidden "Go Back" item at the very top of each sub-menu).
The recovery will show a verification failed prompt for most packages that are not signed with the AOSP keys. This is safe to ignore.
Installing LineageOS 17.1
The LineageOS image must be installed via LineageOS recovery.
1. Download `lineage-17.1-Atom_L-XXX.zip`
2. Reboot your device into recovery (`adb reboot recovery` or simply hold volume up while turning power on)
3. Wipe all data (factory reset) (THIS DELETES EVEN INTERNAL STORAGE)
4. Choose Apply Update, then Apply Update from ADB
5. Run `adb sideload lineage-17.1-Atom_L-XXX.zip` from your PC
6. Wait for the process to finish. (The recovery might prompt something about verification failure, just ignore it and continue anyway)
7. At this point, you can then sideload the LATEST Magisk and OpenGAPPS Nano at your will (note that the size of the system partition might only be enough for the `nano` variant of OpenGAPPS) (If installing Magisk / OpenGAPPS fails, you can try rebooting into recovery again in advanced menus, then try installing them again)
8. Reboot into system and enjoy (Note that Magisk might cause your device to boot loop once or two but it will eventually boot)
When updating to a newer build, you have to flash the new zip, and then re-flash whatever mod you have installed previously (Magisk / GAPPS).
Download Links
LineageOS:
lineage-17.1-Atom_L-20200828-peter-signed.zip: https://mega.nz/file/bAgh1BZA#jzMs_0e9NUR9NcALXWp51ZeWttM5rl_3K5T8Or9hAW0
- Synchronized updates from LineageOS upstream.
lineage-17.1-Atom_L-20200728-peter-signed.zip: https://mega.nz/file/vBwlmL5D#wpw8RovBHyVFCLFlhQ2H5QAIb0ECXkT4of0FRijiP6A
LineageOS Recovery:
lineage_recovery_20200728.img: https://mega.nz/file/yc4Dnbyb#yx0Ci9p3q9_lfAiXkGfgWDFnRJI-JSGrv3kyawkU3fw
vbmeta:
vbmeta.zip: https://mega.nz/file/nF51mBoY#ZNY4j92wc_6a1dXch3l5r-w4VFl9QjN7YJaRMKRoEGk
XDA:DevDB Information
LineageOS 17.1 for Unihertz Atom L, ROM for the Android General
Contributors
PeterCxy
Source Code: https://cgit.typeblog.net/android/device/unihertz/Atom_L/
ROM OS Version: Android 10
Version Information
Status: Alpha
Created 2020-07-28
Last Updated 2020-07-28

How different is the Atom XL?
PeterCxy said:
Introduction
WARNING: DO NOT try to install this on Atom XL. This is ONLY for the Atom L.
Unfortunately I've got the XL version which I thought only varied from the L by the presence of a UHF radio! Can you explain to me why its not a suitable candidate for your mods which sound very good!?
And before you ask, I only got this radio for hacking so I don't mind experimenting if that is required. Please let me know if I can help.
The Bitfarmer
Click to expand...
Click to collapse

tvroman said:
PeterCxy said:
Introduction
WARNING: DO NOT try to install this on Atom XL. This is ONLY for the Atom L.
Unfortunately I've got the XL version which I thought only varied from the L by the presence of a UHF radio! Can you explain to me why its not a suitable candidate for your mods which sound very good!?
And before you ask, I only got this radio for hacking so I don't mind experimenting if that is required. Please let me know if I can help.
The Bitfarmer
Click to expand...
Click to collapse
Because Unihertz publishes completely different firmware files for the L and XL, so the safest assumption is that there is more difference than just the UHF radio. If you want to risk it, then you CAN try using this ROM on the XL, as long as you know how to revert back to official if things go wrong. (But I cannot guarantee if the kernel image from L that this ROM uses will not cause serious issues like corrupted baseband or something on the XL)
My suggestion is that instead of trying this ROM directly on the XL, someone with XL can try to modify my device tree for L, replacing the kernel, dtbo images and other vendor blobs from the ones from XL, and then re-compile the ROM for XL. This would be the proper way to handle these two devices.
Click to expand...
Click to collapse

Going XL
Hi.
Great work. :good:
I want to built a ROM for the Atom XL myself. And because I'm no expert on this (for now) I'm in search of guides and hints on how to achieve my goal.
As far as I know the biggest problem with Unihertz is that they use a Mediatek chipset with which they are not allowed to provide the sourcecode of the kernel. Or at least you have to pay for it from Mediatek.
But there are some variants of the chipset (Helio P60; mt6771) used in other mobile phones (e.g. Nokia X5) for which I was able to find kernelsources on Github. Using these and the latest Android kernel from google I tried to compile a kernel as a starting point. I was able to extract the build.config directly from the phone which helped tremendously. This should at least get me to the point where I'm able to assemble a TWRP build. But I believe that I'm still missing some (vital?) drivers which are specific to the actual device. This includes I think the missing touchscreen driver that you mentioned is preventing the recovery to be useful.
So now I'm a little bit stuck, because most of the guides to arrange a LineageOS (or any other custom ROM) build tree I found require the sourcecode from the manufacturer which we don't have. All other guides to build from scratch were too generic for my current level of expertise.
Can you please share your approach to create this build?
If you don't want to do this in the open you could also PM me.
With kind regards
ADT

a-dead-trousers said:
Hi.
Great work. :good:
I want to built a ROM for the Atom XL myself. And because I'm no expert on this (for now) I'm in search of guides and hints on how to achieve my goal.
As far as I know the biggest problem with Unihertz is that they use a Mediatek chipset with which they are not allowed to provide the sourcecode of the kernel. Or at least you have to pay for it from Mediatek.
But there are some variants of the chipset (Helio P60; mt6771) used in other mobile phones (e.g. Nokia X5) for which I was able to find kernelsources on Github. Using these and the latest Android kernel from google I tried to compile a kernel as a starting point. I was able to extract the build.config directly from the phone which helped tremendously. This should at least get me to the point where I'm able to assemble a TWRP build. But I believe that I'm still missing some (vital?) drivers which are specific to the actual device. This includes I think the missing touchscreen driver that you mentioned is preventing the recovery to be useful.
So now I'm a little bit stuck, because most of the guides to arrange a LineageOS (or any other custom ROM) build tree I found require the sourcecode from the manufacturer which we don't have. All other guides to build from scratch were too generic for my current level of expertise.
Can you please share your approach to create this build?
If you don't want to do this in the open you could also PM me.
With kind regards
ADT
Click to expand...
Click to collapse
You don't need the kernel source code to build a working ROM -- just look at my device tree for Atom L. I think you can build a working ROM for the XL by just replacing the prebuilt kernel in my device tree with the one from Atom XL and also re-extracting the vendor blobs from XL using the script in my devcie tree, then rename everything to Atom XL instead of L. I don't know if the integrated amateur radio would still work though.

PeterCxy said:
You don't need the kernel source code to build a working ROM -- just look at my device tree for Atom L. I think you can build a working ROM for the XL by just replacing the prebuilt kernel in my device tree with the one from Atom XL and also re-extracting the vendor blobs from XL using the script in my devcie tree, then rename everything to Atom XL instead of L. I don't know if the integrated amateur radio would still work though.
Click to expand...
Click to collapse
I'm already on to that.
But I seem to have trouble extracting the prebuilt kernel. None of the tools I found gave me the exact files you have got (dtb.img, dtbo.img, Image.gz). What did you use?
The best I could get were "dtb", "kernel" and "dtborecovery" (without extensions) which roughly had the same size as yours.
Also, as far as I understand it, with your initial commit (without the modifications for Lineage itself) I should be able to at least compile a recovery image but I got an error regarding a missing dtb.img file in the "out" directory.
Something seems to be missing because, my dtb file is in the "device" directory and not being transfered into "out" during building.
I'm not sure that is because I have got a different naming scheme (renamig it didn't help) or I did something wrong with the extraction.
---------- Post added at 07:30 ---------- Previous post was at 07:14 ----------
Another question I have:
Are the vbmeta-files you used to flash the recovery the ones from the original firmeware zip from unihertz or did you get them from the lineage built?
And reguarding the rather smallish system partition:
I have an idea to bypass that by using the SPFlash Tool from Mediatek. As far as I understand the settings in the scatter-file this tool does a repartitioning of the internal storage. So we only need to "decrease" the userdata, "move" some partitions inbetween and "increase" the system. Only problem is, I couldn't find a partition designated as "system" in the scatter-file, only one big "super" and a "vbmeta-system" (which for my understaning is for verified boot) partition.
What do you think?

a-dead-trousers said:
I'm already on to that.
But I seem to have trouble extracting the prebuilt kernel. None of the tools I found gave me the exact files you have got (dtb.img, dtbo.img, Image.gz). What did you use?
The best I could get were "dtb", "kernel" and "dtborecovery" (without extensions) which roughly had the same size as yours.
Also, as far as I understand it, with your initial commit (without the modifications for Lineage itself) I should be able to at least compile a recovery image but I got an error regarding a missing dtb.img file in the "out" directory.
Something seems to be missing because, my dtb file is in the "device" directory and not being transfered into "out" during building.
I'm not sure that is because I have got a different naming scheme (renamig it didn't help) or I did something wrong with the extraction.
---------- Post added at 07:30 ---------- Previous post was at 07:14 ----------
Another question I have:
Are the vbmeta-files you used to flash the recovery the ones from the original firmeware zip from unihertz or did you get them from the lineage built?
And reguarding the rather smallish system partition:
I have an idea to bypass that by using the SPFlash Tool from Mediatek. As far as I understand the settings in the scatter-file this tool does a repartitioning of the internal storage. So we only need to "decrease" the userdata, "move" some partitions inbetween and "increase" the system. Only problem is, I couldn't find a partition designated as "system" in the scatter-file, only one big "super" and a "vbmeta-system" (which for my understaning is for verified boot) partition.
What do you think?
Click to expand...
Click to collapse
> None of the tools I found gave me the exact files you have got (dtb.img, dtbo.img, Image.gz). What did you use?
There is a tool called `unpack_bootimg` in the Android source code. Just run `make unpack_bootimg` in the root directory of the Android source tree and you will get one in the output directory. (btw I have renamed those extracted files so the names won't exactly match, but you need this tool to extract the correct images. All other tools won't work properly).
> my dtb file is in the "device" directory and not being transfered into "out" during building.
Because most tools other than `unpack_bootimg` extracts dtb incorrectly.
> Are the vbmeta-files you used to flash the recovery the ones from the original firmeware zip from unihertz or did you get them from the lineage built?
Those don't matter. Either will work as long as you flash it with the correct parameters as given in my post.
> And reguarding the rather smallish system partition
No don't do that. Android 10 does not use a separate system partition anymore, instead both system, vendor and product are sub-partitions in a huge super partition. When flashing a new ROM, the partitions are automatically resized to match the new image exactly, instead of leaving free space unused like before Android 10. That's why I need to reserve space in BoardConfig.mk for gapps to be installed correctly.

Still not able to build.
PeterCxy said:
There is a tool called `unpack_bootimg` in the Android source code. Just run `make unpack_bootimg` in the root directory of the Android source tree and you will get one in the output directory. (btw I have renamed those extracted files so the names won't exactly match, but you need this tool to extract the correct images. All other tools won't work properly).
Click to expand...
Click to collapse
I'm still getting an error:
Code:
FAILED: ninja: 'out/target/product/Atom_XL/dtb.img', needed by 'out/target/product/Atom_XL/boot.img', missing and no known rule to make it
Comparing your BoardConfig.mk with mine shows a slight difference in the offset and size values which could be associated with the different kernels of the phones.
But using "unpack_bootimg" I didn't get a value for "BOARD_KERNEL_OFFSET" like you have it in your config. Could this be the problem?
Your BoardConfig.mk
My BoardConfig.mk
Do you see anything else out of the ordinary?
(Because I'm doing everything what you did step-by-step the links point to the best matching commits)
Despite not being able to compile right now I tried to press on with integrating your changes in the hopes that it will be fixed somehow later on
So I'm currently stuck on this commit of yours:
Atom_L: import overlay from official vendor
Where did you get the "config.xml" and "power_profile.xml" from? The best thing I could find was a "power_profile.xml" inside "/vendor/overlay/FrameworkResOverlay/FrameworkResOverlay.apk" which seems to be a "compiled" version of the aforementioned xml-file.

a-dead-trousers said:
I'm still getting an error:
Code:
FAILED: ninja: 'out/target/product/Atom_XL/dtb.img', needed by 'out/target/product/Atom_XL/boot.img', missing and no known rule to make it
Comparing your BoardConfig.mk with mine shows a slight difference in the offset and size values which could be associated with the different kernels of the phones.
But using "unpack_bootimg" I didn't get a value for "BOARD_KERNEL_OFFSET" like you have it in your config. Could this be the problem?
Your BoardConfig.mk
My BoardConfig.mk
Do you see anything else out of the ordinary?
(Because I'm doing everything what you did step-by-step the links point to the best matching commits)
Despite not being able to compile right now I tried to press on with integrating your changes in the hopes that it will be fixed somehow later on
So I'm currently stuck on this commit of yours:
Atom_L: import overlay from official vendor
Where did you get the "config.xml" and "power_profile.xml" from? The best thing I could find was a "power_profile.xml" inside "/vendor/overlay/FrameworkResOverlay/FrameworkResOverlay.apk" which seems to be a "compiled" version of the aforementioned xml-file.
Click to expand...
Click to collapse
> Comparing your BoardConfig.mk with mine shows a slight difference in the offset and size values which could be associated with the different kernels of the phones.
TARGET_KERNEL_OFFSET should normally always be 0x00008000. Also, your other offset values seem to be wrong too -- those values from `unpack_bootimg` cannot be filled in directly to BoardConfig.mk. Instead, you need to subtract BOARD_KERNEL_BASE from them (e.g. BOARD_RAMDISK_OFFSET should be 0x55000000 - 0x40078000, which is 0x14f88000, the same as mine). In fact, I think those parameters should be exactly the same for XL and L. Other than that, I don't think I can see much of a problem about your makefiles.
However, note that not all of my historical commits represent a compilable state of the device tree. I'd suggest you start directly from the latest state and just replace whatever is relevant instead of starting over. And there should not be much that needs changing at all except device names, fingerprints and the proprietary vendor files.
> Where did you get the "config.xml" and "power_profile.xml" from
Exactly from those apks. Just decompile them using apktool.

PeterCxy said:
TARGET_KERNEL_OFFSET should normally always be 0x00008000. Also, your other offset values seem to be wrong too -- those values from `unpack_bootimg` cannot be filled in directly to BoardConfig.mk. Instead, you need to subtract BOARD_KERNEL_BASE from them (e.g. BOARD_RAMDISK_OFFSET should be 0x55000000 - 0x40078000, which is 0x14f88000, the same as mine). In fact, I think those parameters should be exactly the same for XL and L. Other than that, I don't think I can see much of a problem about your makefiles.
Click to expand...
Click to collapse
Still giving me errors.
So I tried a very unconventional approach: I just copied the file myself into the mentioned "out/target/product/Atom_XL" folder.
For now it's still compiling. Fingers crossed.
PeterCxy said:
However, note that not all of my historical commits represent a compilable state of the device tree. I'd suggest you start directly from the latest state and just replace whatever is relevant instead of starting over. And there should not be much that needs changing at all except device names, fingerprints and the proprietary vendor files.
Click to expand...
Click to collapse
I just reached your biggest commit yet.
Can you tell me how you got the list of needed files? I hope it's not through trial-and-error.
Except for the values in "setup-makefiles.sh" only the "proprietary-files.txt" seems to be device specific. Is there anything else I need to be aware of in this commit?
P.S.: I know it is tedious to go through your commits one by one but I want to learn something of it not just simply copying what you did. To get a feeling where the biggest pitfalls are and what you did to circumvent them.

a-dead-trousers said:
Still giving me errors.
So I tried a very unconventional approach: I just copied the file myself into the mentioned "out/target/product/Atom_XL" folder.
For now it's still compiling. Fingers crossed.
I just reached your biggest commit yet.
Can you tell me how you got the list of needed files? I hope it's not through trial-and-error.
Except for the values in "setup-makefiles.sh" only the "proprietary-files.txt" seems to be device specific. Is there anything else I need to be aware of in this commit?
P.S.: I know it is tedious to go through your commits one by one but I want to learn something of it not just simply copying what you did. To get a feeling where the biggest pitfalls are and what you did to circumvent them.
Click to expand...
Click to collapse
> Still giving me errors.
Looks like that dtb.img error was totally my fault -- it was due to my jerry-rigged solution of using prebuilt dtb image that conflicted with one of Lineage's update in August and I haven't built the ROM for a month. Now I have fixed it in the latest commit.
> Can you tell me how you got the list of needed files?
All of those files are for VoLTE support and I started with the list from a commit in Redmi Note 7 Pro's device tree that imported those VoLTE blobs, and then added what was missing one by one (when something is missing the Phone process will crash and you can see what got missing in the logs). I don't think the list will be any different on Atom XL so you can just use the one in my device tree.

Hi.
Thanks to you everything is running smoothly here. But what bugs me is that TWRP is not working on our devices.
Although for the Atom there is a possibility: https://forum.xda-developers.com/android/development/twrp-modded-to-unihertz-atom-t3885793
Before I want to go public with my build I wanted to solve this last "mystery".
So I tried to include it in my current source tree according to the (official?) guide but some errors prevented me from a successful build.
Naturally I asked for some guidance at the most reasonable places I know of but got nothing so far:
https://forum.xda-developers.com/showpost.php?p=83443611&postcount=4622
https://forum.xda-developers.com/showpost.php?p=83455271&postcount=4623
https://github.com/TeamWin/android_bootable_recovery/issues/70
I even tried different repositories (omnirom/android_bootable_recovery) and revisions (android-9.0) but these resulted in missing library "type" (static vs. shared) errors so I assume these are too old for LineageOS 17.1
What I want to know is how you managed to get TWRP to built for your device even though the touchscreen wasn't working?
Did you use your LineageOS source tree or one of the many "minimal" manifests? If so, which one would be the "best" to use?
wkr ADT

@PeterCxy and @a-dead-trousers
Thanks for all the work on this so far. I've got an Atom L and have gotten the ROM's PeterCxy posted running on them as in the OP. Do either of you have a quick step-by-step workflow of how you got all the Lineage sources set up and built into the various ROMs? I'd like to be able to build the ROMs from scratch and understand the process.
If I can get caught up to where you two are at with the builds, I can help debug, test and work through issues.

dirtylimerick said:
[MENTION=5351691] Do either of you have a quick step-by-step workflow of how you got all the Lineage sources set up and built into the various ROMs? I'd like to be able to build the ROMs from scratch and understand the process.
If I can get caught up to where you two are at with the builds, I can help debug, test and work through issues.
Click to expand...
Click to collapse
I documented my steps to setup up the build environment in the readme of my repo:
https://github.com/ADeadTrousers/android_device_Unihertz_Atom_XL
But leave out the TWRP part. It isn't working yet mostly because TeamWin/android_bootable_recovery and LineageOS/android_bootable_recovery are too similar.
To figure out all the bits and pieces needed for the device I followed the commit log of @PeterCxy build.

Hi, @PeterCxy.
Finally I was able to build a TWRP recovery and surprise, surprise the touchscreen isn't working.
But during my attempts to get a working TWRP build I came acros a guide that explains how to patch the kernel to get the touchscreen to work.
https://forum.hovatek.com/thread-27132.html
So I tried to follow it but failed to identify the "end" of the zipped Image-file (step 18) to remove the payload from the gz-file. Regardless of which of the null-bytes I use for cutting I always get a warning from 7-zip that there is still data at the end.
Do you know a better approach to achieve this whole patching? Maybe even come up with a scripting solution to easily apply this patch in later builds?
wkr ADT

a-dead-trousers said:
Hi, @PeterCxy.
Finally I was able to build a TWRP recovery and surprise, surprise the touchscreen isn't working.
But during my attempts to get a working TWRP build I came acros a guide that explains how to patch the kernel to get the touchscreen to work.
https://forum.hovatek.com/thread-27132.html
So I tried to follow it but failed to identify the "end" of the zipped Image-file (step 18) to remove the payload from the gz-file. Regardless of which of the null-bytes I use for cutting I always get a warning from 7-zip that there is still data at the end.
Do you know a better approach to achieve this whole patching? Maybe even come up with a scripting solution to easily apply this patch in later builds?
wkr ADT
Click to expand...
Click to collapse
There is no sane way to solve the problem without kernel source code. Basically the stock kernel just does not load the touch screen driver in recovery mode. That patching guide is pretty out of date and I imagine it won't work on most recent kernels. The only proper way is to pressure Unihertz to actually obey GPLv2 and release their kernel source code. Or maybe someone can try reverse-engineering the kernel, but at least I won't do it because it'll just be too much of a hassle.

PeterCxy said:
There is no sane way to solve the problem without kernel source code. Basically the stock kernel just does not load the touch screen driver in recovery mode. The only proper way is to pressure Unihertz to actually obey GPLv2 and release their kernel source code.
Click to expand...
Click to collapse
I'm with you on this one, but as long as we don't have the source code we need to resort to other means to achieve our goals.
PeterCxy said:
That patching guide is pretty out of date and I imagine it won't work on most recent kernels.
Click to expand...
Click to collapse
Yeah it's from way back in 2019
Anyway, with a little bit of tinkering I was able to modify my kernel to load the touchscreen driver in recovery mode.
Here is the device tree and the manifest i used.
I wouldn't recommend to use it in it's current state at all though because the fstab needs a little bit of tinkering. Everything seems to be either unordered or not mounted properly and I fear anything you do in there now will mess up the whole device. BUT I got the touchscreen goin for me which is nice.
PeterCxy said:
Or maybe someone can try reverse-engineering the kernel, but at least I won't do it because it'll just be too much of a hassle.
Click to expand...
Click to collapse
As soon as I have everything sorted out that needs to be fixed on my build (e.g. signing, radio, included gapps working properly, TWRP) I want to dig deeper into the kernel.
There are some devices with Helios P60 out there from other vendors which offer kernel sources.
P.S.: I also uploaded a HOW-TO in my device tree.
If you or someone else wants to try it. Also if you want to you can send me a "symbl.txt" (see to the HOW-TO) extracted from your device then I can do the patching for the Atom_L too.

a-dead-trousers said:
I'm with you on this one, but as long as we don't have the source code we need to resort to other means to achieve our goals.
Yeah it's from way back in 2019
Anyway, with a little bit of tinkering I was able to modify my kernel to load the touchscreen driver in recovery mode.
Here is the device tree and the manifest i used.
I wouldn't recommend to use it in it's current state at all though because the fstab needs a little bit of tinkering. Everything seems to be either unordered or not mounted properly and I fear anything you do in there now will mess up the whole device. BUT I got the touchscreen goin for me which is nice.
As soon as I have everything sorted out that needs to be fixed on my build (e.g. signing, radio, included gapps working properly, TWRP) I want to dig deeper into the kernel.
There are some devices with Helios P60 out there from other vendors which offer kernel sources.
P.S.: I also uploaded a HOW-TO in my device tree.
If you or someone else wants to try it. Also if you want to you can send me a "symbl.txt" (see to the HOW-TO) extracted from your device then I can do the patching for the Atom_L too.
Click to expand...
Click to collapse
Happy to hear that you were able to figure the touchscreen out. I tried to port TWRP at the very beginning when I started tinkering with the device but quickly grew frustrated and just ported Lineage Recovery instead. I guess I might try patching the kernel image too at some point later.
BTW, for TWRP to work with devices released after Android 10, I'm pretty sure you need an extra set of patches that are not yet fully merged to the main TWRP repository. I remember there's some guy providing another manifest with all the patches applied but I couldn't remember the name.

Hi.
I just officially announced my build for the Atom XL:
https://forum.xda-developers.com/android/development/rom-lineageos-17-1-unihertz-atom-xl-t4171407
Could you please put a link in your first post for those in search of the Atom XL and found your thread instead. Thanks.
wkr ADT

hi @PeterCxy.
During my daily usage of the phone I encountered a strage problem:
The audio jack isn't working. Plugging in some headphones I get this slight click in the earpieces when the circuits connect but nothing else happens. Neither a "headphone" icon in the status bar nor hearing anything coming from the headphones itself. The main speaker of the phone keeps playing the music. Using bluetooth everything is working as expected though. So I used logcat to see if something is coming up during plugging in but nothing "catchy" shows up in the logs. My guess is that some (vendor?) service is missing or not started during booting. Next I checked If something shows up on logcat during boot but I'm not sure for what to look exactly. There are quite a few errors and warnings though. In my despair I started to "fix" the "avc: denied" (SEPolicy) entries. Thats when I found a specific error reguarding VoLTE. Maybe this would fix the problems you had with VoLTE in enforcing mode:
https://github.com/ADeadTrousers/an..._Atom_XL/blob/master/sepolicy/private/init.te
(The line with "socket_device:sock_file")
My provider doesn't support VoLTE so I'm not sure if this helps or not. Maybe you could check it.
Anyway can you please tell me if your device's audio jack is working or not?
If you're (by some mysterious coincidence) not affected by this, can you at least give me some pointers for what to look for to get this fixed on my side.
The Internet Is not very helpful when searching for "android audio jack" or something similiar.
Thanks in advance.
wkr ADT

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