HTC HD2 (htc-leo)

Features
Flashing	Works
USB Networking	Broken
Internal storage
SD card
Battery	Works
Screen	Works
Touchscreen	Works
Multimedia
3D Acceleration	Broken
Audio
Camera
Camera Flash
Connectivity
WiFi	Works
Bluetooth
GPS
NFC
Modem
Calls
SMS
Mobile data
Miscellaneous
FDE
USB OTG
HDMI/DP
Sensors
Accelerometer
Magnetometer
Ambient Light
Proximity
Hall Effect
Haptics
Barometer

HTC HD 2
	; HTC HD2
Manufacturer	HTC
Name	HD 2
Codename	htc-leo
Released	2009
Type	handset
Hardware
Chipset	Qualcomm Snapdragon S1 (QSD8250)
CPU	1.0 GHz Scorpion
GPU	Adreno 200
Display	480x800
Storage	512 MB / 1024 MB
Memory	576 MB
Architecture	armv7
Software
Original software	Windows Mobile
Original version	6.5 Professional
postmarketOS
Category	testing
Pre-built images	no
Mainline	partial

Contributors

Langoor
(others on IRC)
Dominduchami
(others on the Matrix chat : Henri Dellal, knuxify and others)

What works

Kernel boots
Display and touchscreen works
Boots with xfce and mate (UI's that require 3D acceleration are not working)
Wifi works correctly

What does not work

Usb networking
3D acceleration
Everything else

Bootloaders

Because of the age of the HD2, there are serval 3rd party bootloaders available, most commonly used:

Haret, Haret is a bootloader (provided as haret.exe) to boot linux or android from WITHIN windows mobile, you start windows mobile, not a great choice for postmarketOS.
a(MagLDR), proprietary 3rd party bootloader developed by Cotulla and DFT, some folks over at Tytung's android forum, tried to reverse engineer it and created aMagLdr (1.13.04), unfortunately still proprietary
cLK, based on littlekernel and download possible with cwm or twrp recovery embedded, seems to be the best option. Littlekernel also provides fastboot wich is handy. Only this bootloader is tested right now.
An open source port of EDK2 is available here

Mainline Kernel

A close-to-mainline kernel port is available here with basic support for :

screen via the EFI framebuffer
interrupt controller
timer

Installation

Install HSPL
Install the CLK bootloader

MAGLDR would probably also work, but using CLK is easier because of fastboot access.

Install the rootfs using an SD Card pmbootstrap install --sdcard=/dev/sd?
Insert the SD Card
Boot the device into the CLK bootloader
Flash the kernel to the boot partition using pmbootstrap flasher flash_kernel (flashing to the additional partitions such as sboot or tboot should work too)
Select the first option (or the other boot partion if it was chosen in the previous step) to boot the kernel.

Flashing the rootfs and the kernel to NAND would probably work on the T-mobile US version of HD2 (it has 1gb of storage space), but it is untested for now.

Hardware

USB: ci-hdrc-usb2
Light sensor: Capella CM3602
Wi-Fi: Broadcom BCM4329
Magnetometer: Asahi Kasei AK8976A
Battery charger: DS2746

How the wlan support was done

Find what wlan chip is being used : bcm4329 in this case
Read WiFi page
Check what package contains firmware for the chip, in this case it is "firmware-aosp-broadcom-wlan"
Change the firmware path in the kernel config
Add a nonfree_firmware section :

nonfree_firmware() {
	pkgdesc="Wifi firmware"
	depends="firmware-aosp-broadcom-wlan"
	mkdir "$subpkgdir"
}

Update checksums, rebuild device and linux packages and boot the device