> is there an android terminal? I'm only familiar with debugging mobile devices over adb and it's restricted.
> I'm aware of android terminal apps, but they typically connect to a remote terminal via SSH.
You certainly can run a local terminal (I think I've seen it baked in as part of developer options, but also as an extra app), though if you don't have root it is somewhat restricted in what you can actually do.
> Does android boot into a terminal like a typical linux device? I thought it booted into fastboot
I think you're slightly misunderstanding how boot works on both Android and Desktop Linux. The kernel is perfectly happy to run whatever you want on such displays as are available. Android tends to boot from firmware (which also implements fastboot) to a bootloader to the kernel and the kernel brings up the system with SurfaceFlinger (the Android display manager) owning the screen. On desktop linux there's more diversity; you can have the kernel initially hand your screen to the old in-kernel virtual terminal, the newer KMS implementation of a terminal ( https://wiki.archlinux.org/title/KMSCON ), or to Xorg or a Wayland compositor (in that case, optionally using plymouth or the like to replace even the earliest text messages). (Actually, full disclosure: I'm only about 70% sure I've got that sequence right. The point is that even desktop linux is perfectly capable of booting only in graphical mode; booting to a text terminal is available but optional.)
Look it's a bunch of theory right now. From what I can tell, your examples would still need integrating into AOSP-- not something that is running right now. I may have a different definition of "shipped" but this wouldn't meet my bar and seems to be more work.
It's possible you are a wizard and I'm a novice so I can't wait to see your demo soon.
No, it's not a theory; I'm describing to you how Android has worked for at least the last decade. If you have an Android phone, this is how the device in your hand works today.
It appears that you and I are having different conversations. I said that 1. it is currently possible to run a terminal on Android, which lets you run commands as an unprivileged user on the Android system, and 2. both Android "typical" Linux are perfectly capable of booting into a graphical environment, though non-Android Linuxes frequently allow you to boot to a virtual terminal as well preferentially. Having gone through the whole thread, I guess by "is there an android terminal?" you actually meant to ask "is there an android terminal that gives you a shell inside a transparent VM like ChromeOS does with Crostini?" If that's what you mean, then it's true that that's less developed (though it does exist - https://www.esper.io/blog/android-dessert-bites-13-virtualiz... is one of the better practical guides I've seen for "how do I run a linux VM on my phone?"). Although if that's the main thing you're asking about, I don't understand why we're talking about boot processes at all; VMs in both Android and ChromeOS (and server and desktop Linux, while we're mentioning) are more or less just fancy user applications, they don't affect the boot process.
> I'm aware of android terminal apps, but they typically connect to a remote terminal via SSH.
You certainly can run a local terminal (I think I've seen it baked in as part of developer options, but also as an extra app), though if you don't have root it is somewhat restricted in what you can actually do.
> Does android boot into a terminal like a typical linux device? I thought it booted into fastboot
I think you're slightly misunderstanding how boot works on both Android and Desktop Linux. The kernel is perfectly happy to run whatever you want on such displays as are available. Android tends to boot from firmware (which also implements fastboot) to a bootloader to the kernel and the kernel brings up the system with SurfaceFlinger (the Android display manager) owning the screen. On desktop linux there's more diversity; you can have the kernel initially hand your screen to the old in-kernel virtual terminal, the newer KMS implementation of a terminal ( https://wiki.archlinux.org/title/KMSCON ), or to Xorg or a Wayland compositor (in that case, optionally using plymouth or the like to replace even the earliest text messages). (Actually, full disclosure: I'm only about 70% sure I've got that sequence right. The point is that even desktop linux is perfectly capable of booting only in graphical mode; booting to a text terminal is available but optional.)