edge: new post: PinePhone Pro platform firmware

This should probably only be merged after Tow-Boot has had a first official release for the PinePhone Pro. Currently builds can be downloaded from a pull request and can be considered stable but it will leave a bit of a bad impression on users if we don't point them to a proper release. A first official release with PPP support has been made!

content/edge/2022-03-28-ppp-tow-boot.md

+title: "PinePhone Pro: flashing Tow-Boot to the SPI and new pmOS installation required"
+date: 2022-03-28
+---
+We plan to merge
+[pmb!2870](https://gitlab.com/postmarketOS/pmaports/-/merge_requests/2870)
+in two days, on Wednesday 2022-03-30. Once it is merged, the PinePhone Pro
+will boot with UEFI in postmarketOS. The supported way to boot the PPP with
+postmarketOS from then on is through [Tow-Boot](https://tow-boot.org), which
+needs to be flashed to the SPI.
+
+**Previous postmarketOS installations will not boot anymore** unless both
+Tow-Boot has been flashed to the SPI, and a new installation with pmbootstrap
+has been performed. Otherwise it will fail due to the boot partition not being
+formatted with FAT32 (if only installing Tow-Boot without reinstalling) or
+because extlinux.conf has been deleted (if only upgrading the existing install
+without installing Tow-Boot).
+
+Note that the PinePhone Pro is still in the testing category of devices, and
+this is the edge channel. We don't make such radical, breaking changes on
+stable and should be able to avoid them in edge once the device enters a higher
+[device category](https://wiki.postmarketos.org/wiki/Device_categorization).
+
+### Motivation
+This deprecates the custom U-Boot build we used before with PPP-specific
+patches. As of writing, we get the following advantages with Tow-Boot:
+
+* Installing postmarketOS to the eMMC is now possible
+* USB Mass Storage mode (similar to JumpDrive)
+* [Standardizing the boot process](https://tuxphones.com/booting-arm-linux-the-standard-way/)
+
+
+### Steps
+
+Wait until [pmb!2870](https://gitlab.com/postmarketOS/pmaports/-/merge_requests/2870)
+is merged and related binary packages have been built
+(see [bpo](https://build.postmarketos.org)). Then hold off with upgrading your
+existing installation and follow the *Installing Tow-Boot on the SPI* and
+*Installing postmarketOS* sections in the already updated
+[PinePhone Pro](https://wiki.postmarketos.org/wiki/PINE64_PinePhone_Pro_(pine64-pinephonepro))
+wiki page.