Needed -- Clarification of Boot SequenceInstructions

[tckosvic]

The PPP wiki describes the permanent and a temporary boot sequence.  I find the wiki to conflict itself.  I think many users are showing confusion and posting numerous threads because they don't understand what is being told to them.  There is also another batch of new user coming. Toward that end, I have extracted the Boot Sequence discussion from the wiki.  I have posted my comments (in red) next to each line.  Hopefully this can get to the root of alot of confusion if someone can provide the mods.  If I have made bad interpretations, I'd like to know.

Boot Order:
On the PinePhone Pro the eMMC (the internal storage of the phone) has a higher boot priority than the microSD card (see boot sequence details for details regarding the boot sequence). That behavior is in contrast to the original PinePhone with the Allwinner A64 SoC, where the microSD card has a higher boot priority. (OK)

The Explorer Edition comes with a modified U-Boot pointing to the microSD card pre-installed to the eMMC. (OK, but no reason why)
The microSD card can be (temporarily) booted instead of the pre-installed operating system, when the power key is shortly held at boot. (Says temporary sd boot)
To always boot from the microSD card it is recommended to wipe U-Boot from the eMMC.(This conflicts with 1st line above.  Removing the temporary UBoot would make it go back to eMMC, it looks to me.  Also, does not say specifically what file to remove.
When the pre-installed bootloader was overwritten with a bootloader without such a configuration, the RE button underneath the back cover of the phone can also be used to temporarily bypass the eMMC. (what does "was" mean?  What configuration, does this mean a configuration with the temporary UBoot removed? I think this says the RE button can also make device boot from SD.  Does not say how to apply RE; one press-then power on, hold down, hold down and press power on?)
The button may however only be pressed shortly for a few seconds during boot, otherwise the eMMC won't be initialized in the operating system.  ( This seems to conflict with previous statement and says hold RE for a few seconds makes boot to eMMC.  Previous statement said it would bypass eMMC and boot to sd.)

Also, further down in wiki, in a yellow box. 

Due to the specific boot order it is currently strongly recommended to boot from the microSD card only. Please ask in the community chat if you have any questions regarding the installation  (no reason given as to why to boot from SD and not the eMMC that any phone should run from.  Also does not say this is a temporary thing.)

Thanks for reading this and also for any clarifications.      tom kosvic

[fxc]

The boot order paragraph was containing outdated information, I've updated it and removed apparently confusing details.

As this is your second forum post here now (why does it need a second one?), can you clarify what your exact question is? You're expressing general confusion but it is impossible to answer your questions if you don't say where the issue is.

[tckosvic]

The boot order paragraph was containing outdated information, I've updated it and removed apparently confusing details.

As this is your second forum post here now (why does it need a second one?), can you clarify what your exact question is? You're expressing general confusion but it is impossible to answer your questions if you don't say where the issue is.

There are two questions because they are different queries.

---

The boot order paragraph was containing outdated information, I've updated it and removed apparently confusing details.

As this is your second forum post here now (why does it need a second one?), can you clarify what your exact question is? You're expressing general confusion but it is impossible to answer your questions if you don't say where the issue is.

Can the wiki now be interpreted to read that the pre-flashed install boots by default from eMMC not SD?  Does not say so specifically.  If so, thanks for the clarification.

Down below, wiki still says: "Due to the specific boot order it is currently strongly recommended to boot from the microSD card only. Please ask in the community chat if you have any questions regarding the installation"

Is this still in play? Also, why is it strongly recommended to boot from SD?

[fxc]

Can the wiki now be interpreted to read that the pre-flashed install boots by default from eMMC not SD?  Does not say so specifically.  If so, thanks for the clarification.

Down below, wiki still says:  "Due to the specific boot order it is currently strongly recommended to boot from the microSD card only. Please ask in the community chat if you have any questions regarding the installation"

Is this still in play?  Also, why is it strongly recommended to boot from SD?

Regarding question 1: There are different boot orders. One is the boot order of the SoC. And one is the boot order of U-Boot. The U-Boot boot order can be changed, so for example the phone can boot the bootloader of the eMMC, which itself points to the microSD card. However if something goes wrong in the eMMC bootloader you still have to use the hardware bypass button, which comes to question 2:

Regarding question 2: If there is no bootloader on the eMMC the phone will default to the microSD card. Which means that if your OS is getting corrupted you simply reflash the microSD card. If you flash something to the eMMC and it gets corrupted (which will happen!) the recovery effort is considerably higher (hardware bypass, flashing a microSD card, reflashing the eMMC). Additionally there are currently also known bugs like some operating systems not yet being compatible with the eMMC, the phone getting stuck in suspend when the bootloader is started from the eMMC or the boot loop many people are experiencing with the pre-installed OS. So you can flash to the eMMC if you don't value your free time, so that's simply not recommended for now.