#Run it on a phone

The reference phone is the POCO X5 Pro 5G (code name redwood, Snapdragon 778G). hakios boots on it from RAM: nothing is flashed, and a reboot gives Android back. For any other phone, see Adapt it to your device.

Before you start. An unlocked boot loader is required, and unlocking it usually erases the phone. hakios does not charge the battery while it runs, so start with the battery above 50%. Keep the USB cable connected for the whole session.

#What you need

• A POCO X5 Pro 5G with the boot loader unlocked, Android working, and USB debugging on
• adb and fastboot (Google's platform-tools) on your computer
• The main repository, built as in Run it in QEMU: make doctor passes
• The system images from your own restore image: userland/system.apfs (see the Darwin user space)
• A loader with your identity: make loader, once
• The phone's own firmware for the GPU, Wi-Fi, audio, haptics, modem and cameras, pulled from the phone itself (step 2). hakios never ships it.

#The short way: one command

tools/hakios-device.py sync          # the device repository and the UEFI, into devices/ and uefi/
devices/redwood/pull-firmware.sh     # Android running, on adb: the phone's firmware -> fw-*/
make redwood_defconfig               # the phone's configuration: common + SC7280 + redwood
make config                          # check it; it names any problem and the reason
make phone SECS=600                  # a 10-minute session in RAM, the log in logs/

make phone takes the phone from Android to our loader, sends the system image, runs the kernel with the arguments from your .config, fetches the log and leaves the phone in the loader for the next run. To go back to Android when the session ends, add XL_END=android:

XL_END=android make phone SECS=600

#The same, step by step with xl

xl is the script behind make phone. Use it directly to see each stage.

./xl enter                          # Android -> fastboot -> our loader, in RAM
./xl ramdisk userland/system.apfs   # the system image into the phone's RAM (about 80 s), once per loader session
XL_SECS=600 XL_CMDLINE="$(tools/hakios-config.py args)" ./xl run    # a session; the log goes to logs/
./xl reboot                         # back to Android

One run per loader session. A second kernel run in the same loader session has died at once every time it was tried. Between runs, ./xl reload or ./xl reboot.

#Choosing what the kernel turns on

Your .config decides. The arguments it gives look like this:

touchscreen=1 gpu=1 adsp=1 sound=4 wifi=1 haptic=5 modem=1 modem_again=1 modem_buffer=0xa8000000

To add or remove one for a single run, override the line: make phone ARGS="touchscreen=1 gpu=1". To change it for good, edit the device's fragment and run make config again. Every argument that exists is in the boot arguments catalogue.

#Getting back to Android

#Want it to stay? Dual boot

There is a manual procedure that installs hakios beside Android with a boot menu. It erases Android's data, flashes boot_a and has only been done on this phone. Read Installing beside Android in full before running any of it, and back up your partitions first.

#Next

• Everything else that can go wrong: When something goes wrong.
• Use the GPU through Metal: Metal.