#PinePhone on Apache #NuttX RTOS might become a Feature Phone ... But first let's learn about its USB Controller
Someday we might pop a #NuttX microSD into #PinePhone ... And turn it into a Feature Phone!
Article: https://lupyuen.github.io/articles/usb2?2#pinephone--nuttx--feature-phone
#PinePhone might become a #LoRa Communicator ... With the LoRa Back Cover and #Meshtastic
Article: https://lupyuen.github.io/articles/usb2?3#appendix-lora-communicator-for-pinephone-on-nuttx
Inside #PinePhone is Quectel EG25-G LTE Modem ... For 4G Voice Calls, SMS, Mobile Data and GPS
Article: https://lupyuen.github.io/articles/usb2?4#quectel-eg25-g-lte-modem
#PinePhone talks to its Quectel EG25-G LTE Modem over USB
Article: https://lupyuen.github.io/articles/usb2?5#lte-modem-talks-usb
Quectel EG25-G LTE Modem connects to #PinePhone over USB ... That's why we need a PinePhone USB Driver for Apache #NuttX RTOS
Article: https://lupyuen.github.io/articles/usb2?5#lte-modem-talks-usb
#PinePhone's USB Controller works like the Mentor Graphics USB Controller ... Except the USB Registers are scrambled (like eggs)
Article: https://lupyuen.github.io/articles/usb2?6#document-the-usb-controller
Finding a Reference Driver for #PinePhone's USB Controller ... With GitHub Code Search
Article: https://lupyuen.github.io/articles/usb2?7#search-for-usb-driver
GitHub Code Search uncovers the FreeBSD Driver for #PinePhone USB Controller
Article: https://lupyuen.github.io/articles/usb2?8#freebsd-usb-driver
Inside the #FreeBSD Driver for #PinePhone USB Controller
Article: https://lupyuen.github.io/articles/usb2?9#inside-the-freebsd-driver
Understanding #PinePhone's USB Controller ... By comparing the #FreeBSD Driver with the Mentor Graphics USB Doc
Article: https://lupyuen.github.io/articles/usb2?9#inside-the-freebsd-driver
What's inside a USB Controller Driver for Apache #NuttX RTOS
Article: https://lupyuen.github.io/articles/usb2?10#usb-drivers-in-nuttx
#STM32 USB Driver for Apache #NuttX RTOS ... How it enumerates USB Devices
Article: https://lupyuen.github.io/articles/usb2?11#stm32-usb-driver-for-nuttx
Let's look inside the USB Controller of #PinePhone @PINE64 ... And create a USB Driver for Apache #NuttX RTOS
@lupyuen Speaking of FreeBSD drivers…maybe you like this post:
https://freebsdfoundation.org/wp-content/uploads/2021/08/The-Panfrost-Driver.pdf
by https://github.com/bukinr/mdepx
#PinePhone's Allwinner A64 USB Docs are horrigibly lacking ... Thankfully we have the USB Docs by Mentor Graphics
Article: https://lupyuen.github.io/articles/usb2?6#document-the-usb-controller