Boot chain
BootShim, lk1st, and fastboot path.
Experimental computing
Modern systems research on unconventional hardware.
Demonstrated experimental platformPublic repository
The platform
Mainline Linux on a Nokia Lumia 1520.
RegenX AE brings mainline Linux and postmarketOS to an AT&T Nokia Lumia 1520 RM-940 built around Qualcomm’s MSM8974 platform.
The 2013 Windows Phone hardware presents unusual bring-up challenges across the boot chain, TrustZone interfaces, power management, audio, radios, and device-specific drivers.
- Device
- AT&T Nokia Lumia 1520
- Model
- RM-940
- Platform
- Qualcomm MSM8974
Boot architecture
From device boot to mainline userspace.
The boot chain transitions the device from its original platform environment into a mainline Linux / postmarketOS userspace through a staged bring-up path.
- BootShim
Transitions from the Lumia UEFI environment into the project boot path.
- lk1st
Prepares the MSM8974 device for a standard fastboot workflow.
- Fastboot
Loads the verified boot image through the development interface.
- Mainline kernel
Runs the Linux 6.16 platform and ongoing device enablement.
- postmarketOS
Provides the mobile Linux userspace running from eMMC.
Boot path shown for the RM-940 configuration.
Subsystem map
Subsystem bring-up at a glance.
The current RM-940 configuration spans working, partial, blocked, and untested subsystems as hardware enablement continues.
Kernel / userspace
Mainline 6.16 and postmarketOS from eMMC.
Display / backlight
SimpleDRM framebuffer and PM8941 WLED; panel power management remains open.
Multitouch
Synaptics RMI4 multitouch input.
eMMC storage
Stock partitions visible; postmarketOS runs from Data.
microSD media
The controller initializes; removable media remains untested.
USB networking
NCM networking with SSH, plus ACM serial.
Battery telemetry
Voltage, temperature, presence, health, and status reporting.
Battery charging
Charging engages briefly at boot, then latches off.
Suspend / resume
Repeated s2idle suspend/wake cycles passed the recorded acceptance run.
Buttons
Volume and two-stage camera buttons passed press testing.
Sensors
Ambient light and proximity work; three devices remain unidentified.
SMP
TrustZone rejects secondary-core bring-up; nosmp remains required.
Wi-Fi / Bluetooth
Both depend on the blocked WCNSS remoteproc path.
Modem
The separate firmware and processor sequence has not been tested.
Camera
No current camera implementation result.
Audio DSP
ADSP boots with APR and q6core bound.
Audio output
Control-path work is active; analog and audible output remain unverified.
Test result
Suspend / Resume
10/10 tested cycles completed successfully
Repeated s2idle cycles resumed with USB networking and essential services intact on the tested RM-940 configuration.
Bring-up milestones
A staged path to a usable Linux platform.
The work progressed from establishing the boot chain to making the device interactive, accessible over USB, and repeatably suspendable.
Mainline boot
The device reaches postmarketOS from internal storage through the project boot path.
Interactive display / touch
Framebuffer, backlight, and multitouch support make the running system directly usable.
USB development access
NCM networking and SSH establish a repeatable route into the device.
Repeatable suspend / resume
The recorded s2idle acceptance run completes ten clean suspend and wake cycles.
Audio bring-up
Audio bring-up has reached the codec control path.
Current validation reaches reversible codec-control behavior; analog output and audible playback have not yet been demonstrated.
- ReachedADSP and control plane
ADSP boot, APR/q6core, codec discovery, IRQ, and control paths.
- ReachedStream and machine
RX DAI, SLIMbus, QDSP6 paths, machine card, and MCLK work.
- ReachedDAC widget power control
Reversible HPHL widget-control behavior in the recorded path.
- UnverifiedElectrical waveform
No measured analog waveform has been established.
- UnverifiedAudible output
No audible playback has been demonstrated.
Control-path test result
132 control-path checks passed, 0 failed
Audio output remains unverified.
Hardware evidence
Demonstrated on physical Lumia 1520 hardware.
Open the scoped evidence record for the tested RM-940 configuration.
Hardware validation
One RM-940 test platform.
The evidence record identifies the tested hardware, measured result, scope, limitations, and date.
Public repository
Explore the Lumia 1520 mainline work.
Source code, hardware status, technical documentation, and reproducibility material are available in the public repository.
The platform is operational. Hardware enablement continues.
Mainline Linux / postmarketOS boots from internal storage with display, touch, and USB development access working. Radios, SMP, camera, charging behavior, modem support, and full audio output remain incomplete, blocked, or unverified.
GitHub · KorelisLabs
Open public repository
Mainline Linux on the Nokia Lumia 1520
The repository contains the device port, boot-chain documentation, hardware status, tooling, and current bring-up records.
Work with Korelis Labs
Work at the hardware/software boundary.
Platform bring-up, upstream engineering, and unconventional-hardware discussions are welcome.