Replicant

h1. PinePhone

The PinePhone is an AllWinner A64 based smartphone designed and produced by PINE64 that strives to be compatible with fully free software. It is documented in detail at "PINE64's wiki":https://wiki.pine64.org/index.php/PinePhone

h2. Components overview

|_. Feature |_. Hardware |_. Comments |_. TODO |

| System on a chip | Allwinner A64 Quad Core[9] | * The bootloader should be fully free software[7] including ARM Trusted Firmware[8].

* The code should be upstream already[7]. | TODO:

* Look at the code. |

| GPU | Mali 400 MP2 GPU[1] | * A "pipe" driver is in Linux since 5.2

* Has support in Mesa. | |

| Modem |/2. Quectel EG-25G[1] with[2] worldwide bands[4] | * The EG-25G is an international version of the EC25.

* Runs GNU/Linux[18].

* USB connection for data and I2S connection for audio[18].

* Audio connected to both PCM interfaces on the A64[14].

* PCM audio still experimental: sending to the modem works fine, receiving produces mangled samples[14]. 

* AT support commands look unusable[20], so we need to use QMI which is way more robust anyway. | TODO:

* What's the similarity with the EC-25? |

| GNSS[1]: GPS, GPS-A, GLONASS[4] | * Part of the modem.

                                    * It's NMEA protocol variant is already supported by GNU/Linux's gpsd[21].

                                    * The reception is too weak to be usable due to poor antenna design. |

| WiFi |/2. RTL8723cs[3] | * Requires a nonfree loadable firmware[3].

* Connected via SDIO[18]. |/2. TODO:

* Check if firmware is provided under GPLv2 within the Linux driver as "happened in similar chips":https://libreplanet.org/wiki/Group:Hardware/Computers/e-readers/Kobo/Aura_H2O_Edition_2#Firmwares. |

| Bluetooth: 4.0, A2DP[1] | * Requires a nonfree firmware[3].

* Connected via UART[18]. |

| USB – C[1] (Power, Data and Video Out) | |* USB 2.0[9]

* Serial console is only available in the headphone connector (activated by the 6th contact on the dipswitch[10])| |

| RAM | 2 or 3 GB of LPDDR3 RAM | * Initialized by u-boot SPL[18]. | |

| Main Camera | Single OmniVision OV6540, 5MP, 1/4″, LED Flash[1] | * Mainline driver[5]

* No firmware required[5]

* There's an optional non-free firmware for the auto-focus[18]. | |

| Selfie Camera | Single GC2035[1], 2MP, f/2.8, 1/5″ | | |

| Storage | Bootable microSD slot[1]

 16GB eMMC[1] | * Boot order: microSD -> eMMC[6]| |

| Sensors accelerator, gyro, proximity, compass, barometer, ambient light[1] | | | TODO:

* Which chips are used? |

| LCD panel and touchscreen | 5.95″ LCD 1440×720

18:9 aspect ratio (hardened glass) | Probably works with free software[11]. | |

| Power Management IC (PMIC) | AXP803[13] | | |

| Power Management coprocessor | AR100[15] | * The proprietary firmware can be replaced with Crust[16].

* Allows deep power-saving modes and later wake-up.

* Use case: receive signal from modem to wake-up device[17]. | |

h2. Downstream reference code

*Downstream Linux*: -https://gitlab.com/pine64-org/linux- https://xff.cz/git/linux pp-x.xx branches (mirror: https://codeberg.org/megi/linux)

*Downstream u-boot*: -https://gitlab.com/pine64-org/u-boot- (can now use upstream)

*Downstream arm-trusted-firmware*: https://gitlab.com/pine64-org/arm-trusted-firmware

h2. Upstream status

h3. Linux

Current upstreaming work is being led by Ondřej Jirman (aka "megi"): "megi's PinePhone Development Log":https://xnux.eu/log/index.html.

megi publishes kernels after each release with the not-yet-upstreamed patches rebased on top. The commit log thus serves as the best available "to upstream" list: "example for Linux 6.10":https://xff.cz/git/linux/log/?h=pp-6.10

A now (2024) outdated status can be seen at: "megi's feature/driver support matrix":https://xnux.eu/devices/pine64-pinephone.html#toc-feature-driver-support-matrix.

Current upstreaming path looks like this: megi -> sunxi-next -> linux-next -> torvalds

Patches relevant to all A64 devices should be directly sent to sunxi-next.

Patches only relevant to PinePhone may be sent to megi

Previous upstreaming work was done at "PINE64's GitLab":https://gitlab.com/pine64-org/linux/.

h3. U-Boot

PinePhone support was "upstreamed on November 2020":https://source.denx.de/u-boot/u-boot/-/commit/a575c55d1e8a06173c323cac40e3942af8512c85

h2. Audio routing

Check "megi's Audio on PinePhone":https://xnux.eu/devices/feature/audio-pp.html#toc-audio-on-pinephone.

h2. Hardware kill switches

The PinePhone has 6 hardware switches[19] that allow turning on/off different hardware components: modem, WiFi/Bluetooth, microphone, rear camera, front camera and headphones. Unfortunately these are located under the back cover, which needs to be taken out to operate them.

h2. Poor GPS/GNSS reception

There are "many reports":https://forum.pine64.org/showthread.php?tid=11680&page=6 of poor GPS reception on the PinePhone. The "official cause":https://wiki.pine64.org/wiki/PinePhone_FAQ#GPS_doesn't_work is the small antenna in the PinePhone and the suggested fix is to use Assisted GPS (A-GPS), also known as Assisted GNSS (A-GNSS).

A-GNSS "has already been added into Mobian's eg25-manager":https://gitlab.com/mobian1/eg25-manager/-/merge_requests/15/diffs and there is also a "proof of concept script available":https://gist.github.com/alastair-dm/263209b54d01209be28828e555fa6628.

Unfortunately, A-GNSS alone, will not solve the full issue we are experiencing. A-GNSS can only improve the Time To First Fix (TTFF). On GNUtoo's tests with the PinePhone, after the first fix was acquired, just going under some trees in a town sufficed to loose the signal. This hints that, besides being small, the GNSS antenna may suffer some design fault.

On top of that, A-GNSS's most demanded feature, downloading the almanac and ephemeris data from a Secure User Plane Location (SUPL) server to speed up the TTFF, cannot be implemented in Replicant. There exists no SUPL server running free software that we know of.

The Openmoko Freerunner had working A-GNSS and used it only to save and inject back the almanac data, e.g. for faster fixes after closing and opening a navigation app in a short time interval. Unfortunately the almanac and ephemeris data is only valid for a limited period.

In general to make GPS work fine with free software we need the best GPS chips available. What's inside the PinePhone does not seem to be up to par. More testing and tweaking is needed though.

h2. Schematics

All listed at "PinePhone board information, schematics and certifications on PINE64 wiki":https://wiki.pine64.org/index.php/PinePhone#PinePhone_board_information,_schematics_and_certifications.

h2. References

fn1. Some specifications are available at the "device page":https://www.pine64.org/pinephone/ and "wiki page":https://wiki.pine64.org/index.php/PinePhone.

fn2. PinePhone discussion in Replicant's mailing list: https://lists.osuosl.org/pipermail/replicant/2019-July/001997.html

fn3. From #replicant channel on Freenode: <pre><MoeIcenowy> The Wi-Fi changed to RTL8723CS (this chip also does BT), which needs non-free firmware to be feed</pre>

fn4. From #replicant channel on Freenode: <pre><MoeIcenowy> The GNSS should be also done by EG25-G</pre>

fn5. From #replicant channel on Freenode: <pre><MoeIcenowy> The OV5640 camera doesn't need firmware and its driver is mainlined</pre>

fn6. From #replicant channel on Freenode: <pre><MoeIcenowy> The boot order is strictly MicroSD->eMMC, which is set in the A64's boot ROM</pre>

fn7. From #replicant channel on Freenode: <pre><MoeIcenowy> The bootloader (U-Boot SPL + ATF + U-Boot) is free software, all mainlined now (and the downstream dirty U-Boot cannot boot upstream Linux kernel)</pre>

fn8. From #replicant channel on Freenode: <pre><MoeIcenowy> https://github.com/ARM-software/arm-trusted-firmware</pre>

fn9. Allwinner A64 Datasheet: http://files.pine64.org/doc/datasheet/pine64/A64_Datasheet_V1.1.pdf

fn10. PostmarketOS Pinephone page: https://wiki.postmarketos.org/wiki/PINE64_PinePhone_(pine64-pinephone)#Serial_console

fn11. From #replicant channel on Freenode: <pre>

01:48 <adjtm> GNUtoo, lukasz confirmed me that the lcd doesn't require proprietary firmware to be uploaded

01:49 <adjtm> the conversation between pine64 staff about the lcd that someone posted on irc was probably before deciding in

               the last lcd</pre>

fn13. From Xalius on "PINE64 IRC":https://forum.pine64.org/showthread.php?tid=892. Details at: https://linux-sunxi.org/AXP803

fn14. From Xalius.

fn15. https://linux-sunxi.org/AR100

fn16. https://github.com/crust-firmware/crust

fn17. From Xalius.

fn18. PinePhone Misconceptions: https://www.pine64.org/2020/01/24/setting-the-record-straight-pinephone-misconceptions/

fn19. PinePhone at PINE64 wiki: https://wiki.pine64.org/index.php/PinePhone#Killswitch_configuration

fn20. According to Pavel Machek, "there is no RING indication on the AT side":https://pavelmachek.livejournal.com/143504.html ("archive":https://web.archive.org/web/20210913155020/https://pavelmachek.livejournal.com/143504.html) so we might be required to use QMI. QMI is probably a better long term solution anyway.

fn21. GNUtoo tested it with gpsd + some configuration on top of a Mobian image.