Samsung Galaxy Xcover 3 (samsung-xcover3lte)

Contributors

 * Blacksilver

How to enter flash mode
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How to enter recovery mode
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What works

 * XFCE
 * Weston
 * TTYEscape
 * fbkeyboard
 * MUIC/UART

What doesn't work

 * Blanking and Unblanking leads to framebuffer flickering, which stays after reboot and even battery-removal for some time.
 * Only kernels built with GCC4 will boot downstream.
 * AlsaUCM profile must be reapplied before each audio play.
 * LEDs

Installation
Flash the boot-image

Installation of rootfs can be be done either to SD-card

This makes manual dual boot (by replacing boot-image) possible.

Alternatively installation can be done via recovery to USER partition (5.3GB). The system partition is rather small (1536M) for postmarketos with UI.

For installation to USER partition via android-recovery-zip you need a TWRP recovery (codename xcover3ltexx). The latest TWRP recovery isn't flash-able after update to latest vendor version (Android 5.0). A "Hackish TWRP" alternative recovery image can be found in XDA forum.

Boot image
The created pxa-bootimage contains a legacy uImage which is slightly different from vendor one. Despite having keyword  and missing extra gzip compression, it boots as well.

Debugging
To enable ramoops the kernel cmdline must be extended by these module parameters. See also ramoops

After kernel panic the console can be extracted in e.g. recovery.

UART
You can get serial console with a microUSB/Carkit_debug_cable and 619KΩ resistor. The phone will boot when plugging the cable in, after the phone has been powered off or battery inserted. Might take several attempts. 150KΩ will start the phone in flash mode.

Audio
The Alsa UCM usecase must be set before each play, e.g.

Mainline
Mainline boots with patch below.

Create post-make.sh which executes the DTB combiner.

After flashing the phone must be powered off, best by battery removal.

Plugging UART cable in should lead to this output:

Required kernel config options for booting. The kernel size limit is unknown.

Mainline changes and reduced DT.

Attempt to add mainline support for pxa1908 aka iap140 was done in 2017 https://lore.kernel.org/linux-arm-kernel/20170222022929.10540-1-afaerber@suse.de/

Similar devices
The following devices are similar to SM-G388F.


 * Core Prime VE LTE
 * Grand Prime VE LTE
 * Samsung Galaxy J1 ACE (j1acelteltn) - SM-J110m