All this assumes you already have unlocked your bootloader and know how to switch between different modes as well as have some sort of un-bricking method if things go wrong. For RM-1073, check my GitHub Lumia640 Unbrick repo: https://github.com/WolfLink115/Lumia-640-RM-1073_Unbrick

• At the moment this is unknown

• Boots to EDK2 shell
• Linux boots if you use the linux port by Dominduchami

git clone https://github.com/tianocore/edk2 --recursive
git clone https://github.com/tianocore/edk2-platforms
git clone https://github.com/WolfLink115/edk2-msm8x26-lumia

For Ubuntu/Debian-based systems

sudo apt install build-essential uuid-dev iasl git gcc-5 nasm python3-distutils

mkdir workspace
./build.sh

1. Compile Lumia830Pkg & Copy emmc_appsboot.mbn to EFIESP partition
2. Download compiled BootShim and BootShim Patcher from releases page:
3. Copy Stage2.efi to EFIESP partition
4. Rename resetphone.efi to resetphone.efi.bak and move it somewhere to your computer
5. Copy resetphone.efi to MainOS:\EFIESP\Windows\System32\Boot
6. Add "NoIntegrityChecks" to "Reset Phone Application" entry in BCD of your phone:
   • Open Command Prompt as admin, enter the letter for MainOS partition followed by a colon (ex. E:) and run:

   cd EFIESP\efi\Microsoft\boot
   bcdedit /store .\BCD /enum ALL

   • Look for the Reset Phone Application section and copy the UUID for it (UUID ex. {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}). Then run:

   bcdedit /store .\BCD /set <"{UUID-for-ResetPhoneApplication}"> "nointegritychecks" yes

7. Enable DisplayBootMenu in BCD

   bcdedit /store .\BCD /set "{bootmgr}" "nointegritychecks" yes
   bcdedit /store .\BCD /set "{bootmgr}" "testsigning" Yes
   bcdedit /store .\BCD /set "{bootmgr}" "timeout" 5
   bcdedit /store .\BCD /set "{bootmgr}" "displaybootmenu" Yes
   

8. Reboot Phone
9. At the BootMenu press vol down to boot EDK2

1. Open Terminal and install GParted.

   sudo apt install gparted
   

2. Plug your Lumia in Mass Storage Mode into your computer and open GParted.

   Switch to your Lumia's eMMC in gparted and delete the MainOS and DATA partitions (Partition number varies between devices).

   Create a new ext4 partition from the remaining space, name label it MainOS.

3. Run these in terminal, being sure to replace with your preferred username:

   sudo mkdir /mnt/root
   sudo mount </path/to/MainOS> /mnt/root
   sudo debootstrap --arch=armhf <distro> /mnt/root
   
   - To install desktop environment:
   sudo chroot /mnt/root
   apt update
   apt install xfce4 -y
   
   - To setup user profile
   adduser <username>
   usermod -aG sudo <username>
   
   - To setup autologin
   nano /etc/lightdm/lightdm.conf
   
   - Add in "[Seat:*]" section:
   pam-service=lightdm
   pam-autologin-service=lightdm-autologin
   autologin-user=<username>
   autologin-user-timeout=0
   session-wrapper=/etc/X11/Xsession
   Greeter-session=lightdm-greeter
   
   - Press CTRL + X then Y and Enter
   
   - Finishing up, type:
   exit
   umount /mnt/root
   exit
   

4. To set up Linux kernel Copy the zImage, lumia.dtb, and initramfs-linux.img from https://github.com/WolfLink115/linux/releases/tag/v1-alpha to the root of the EFIESP partition.

5. To set up startup.nsh, being sure to replace <mmcblk0p*> with your MainOS partition:

   cat <<EOF > startup.nsh
   zImage dtb=lumia.dtb video=efifb earlycon=efifb root=/dev/<mmcblk0p*> PMOS_NO_OUTPUT_REDIRECT
   EOF
   

6. Reboot and hold volume down to boot Linux

1. Imbushuo for BootShim (https://github.com/imbushuo/boot-shim)
2. Linus Torvalds for Linux kernel (https://github.com/torvalds/linux)
3. Tianocore for EDK2 sources (https://github.com/tianocore/edk2)
4. Konrad Dybcio for writing a porting guide (https://github.com/konradybcio/Lumia-EDK2-Guide)
5. Dominduchami for modified Lumia 830 EDK2 (https://github.com/Dominduchami/Lumia830Pkg)
6. Ivaylo Ivanov for his initramfs-linux.img (https://github.com/ivoszbg)
7. Empyreal96 for Lumia 950XL debootstrap install guide (https://github.com/empyreal96)
8. Aljoshua Hell for introducing me to debootstrap (https://github.com/J0SH1X)
9. postmarketOS team for envkernel.sh script (https://gitlab.com/postmarketOS/pmbootstrap/-/blob/master/helpers/envkernel.sh)
10. Anyone else I may be missing.