Sony Xperia acro S (sony-hikari)
This device uses a non-standard ELF format boot.img file that is not supported by postmarketOS (yet):
% file boot.img boot.img: ELF 32-bit LSB executable, ARM, version 1 (ARM), statically linked, corrupted section header size
intgr has a working hacked postmarketOS toolchain for building compatible boot.img files.
What does not work
After trying out tens of different combinations of kernel sources from the web, I couldn't find any that get as far as initramfs.
The best sources found manage to initialize the display backlight and then crash pretty late in the initialization process with error: (see dmesg)
BUG: Bad page state in process swapper/0 pfn:5dcba
WIP can be seen here: https://gitlab.com/intgr/pmaports/compare/master...device-sony-hikari
No peripherals supported yet, but
/dev/last_kmsg can be extracted with a binary kernel (e.g. TWRP). Sadly the boot process appears to hang after executing
/init: (see dmesg)
WIP can be seen here: https://gitlab.com/intgr/linux-postmarketos/compare/master...device-sony-hikari
How to enter flash mode
Power off the device. Hold Volume Up as you plug the USB cable into the device.
Alternatively, perform a hard reset by holding Power and Volume Up buttons. When the device vibrates, release the Power button *first*, and it will boot into fastboot loader.