lk2nd cannot boot (or automatically reset) on msm8956-sony-loire-kugo (Xperia X Compact)

[Icenowy]

I tried to build a lk2nd-msm8952 and run it with fastboot boot build-lk2nd-msm8952/lk2nd.img on my Docomo Sony Xperia X Compact, the fastboot command succeeded but the phone then reboots itself to normal OS.

My phone's serial number does not start with BH902H as expected in lk2nd/device/dts/msm8952/msm8956-mtp.dts, so I patched it to BH905X (which is what my phone's serial number starts with), but still fails; then I tried to add a * to the end of the match string, still no enhance.

I tried fastboot flash boot build-lk2nd-msm8952/lk2nd.img too and it just bricks my phone into bootloop (I can still use vol+ to activate Sony S1 fastboot and flash back the normal boot partition).

[barni2000]

Are the msm-id and board-id same like on BH902H?

Have you tried fastboot boot build-k2nd-msm8952/lk2nd.img?

Maybe you should try adjust the build a bit like
make LK2ND_ADTBS="msm8956-mtp.dtb" LK2ND_DTBS="" LK2ND_QCDTBS=""

[Icenowy]

I verified msm-id and board-id on a living LineageOS system, and it's correct (the boot.img file contains 4 DTB files, all with MTP board-id and the msm-id corresponds to 8956/8956v1.1/8976/897v1.1, and the 8956v1.1 one seems to be the actual used one).

What do you mean by fastboot boot build-k2nd-msm8952/lk2nd.img? I tried first fastboot boot and then fastboot flash boot (trying the latter is because the S1 bootloader seems to omit enabling display when fastboot).

Not tried building an image with only the mtp dtb, will try it.

[Icenowy]

Built an image with only the MTP dtb, it doesn't work either...

Maybe I should try to let the lk2nd DTB include an true dtb?

[Icenowy]

Prepend a whole / node from a decompiled mainilne msm8956-sony-loire-kugo.dtb (which is tested to boot) before #include <lk2nd.dtsi> fixes nothing...

[barni2000]

What happens if you remove every other device from msm8956-mtp.dts?

Maybe you should attach uart for your device.

[Icenowy]

Unfortunately Sony didn't provide UART position info for X Compact (and I have no ability to access it on a consumer's device)

[barni2000]

Maybe there is a possibility use ramoops/pstore with lk2nd.
If you can define it to same memory range what is used in twrp you could get the logs with adb pull /sys/fs/pstore

[HidingCherry]

Same for Xperia X (suzu) from the loire platform.
I had no luck with getting pstore, the folder was empty.

[Biswa96]

Have you tried to compare the new dts properties from the official Android boot image or from a running Android system?

[HidingCherry]

I'm rather a bit lost at the lk2nd source code.
I have the dts of a working android system though.

Which directories should I check?
Those two?

• platform/msm8952
• target/msm8952

Only the header files?

[Biswa96]

The files in platform/ and target/ are not changed for adding new devices. Compare the dts which you are adding in lk2nd with Android's dts.

[HidingCherry]

Alright, my idea would be to create a dts in

• lk2nd/device/dts/msm8952

and add it to rules.mk

Then I also need to define a panel (probably the main issue) in

• lk2nd/display/panel/generated

and also add it to panels.h

The panel should then be used in the dts.
Did I miss more?
(I have no experience in that matter, so I'm kinda experimenting.)