Create a new special intermediary firmware

[tsusanka]

To make onboarding easier let's create a new firmware, which will update bootloader to its newest version and firmware to the newest version, so user does not have to update (and unplug) its device several times.

[keepkeyjon]

You could skip some of the unplugging with soft resets: /~https://github.com/trezor/trezor-mcu/issues/438

[saleemrashid]

Yes, I had a terrible experience attempting to upgrade an old Trezor to the latest firmware (since the new firmwares are too big for the old bootloader).

[tsusanka]

We will create a new "artificial" firmware, which will perform the first upgrade and then the second one right away. Of course Wallet/Suite needs to support this.

We might also do the soft resets while we are at it.

[mroz22]

Just a little irritating question on possible delivery date of this feature @ZdenekSL
I am asking to know whether I should put more effort into workarounds on trezor-suite side or not.

[hiviah]

So to recap the strategy from intermediate FW's point of view:

1. it updates bootloader to latest version that is packed together with FW
2. copies small shim into RAM to allow current firmware to be erased (compiled to fixed address or position independent)
3. jumps to shim
4. shim deletes firmware
5. shim soft-resets device

[tsusanka]

This bundles the bootloader.dat file. That is the bootloader latest 1.8.0 version right? Could we build a new version 1.8.1 from master and include that one? It includes some new features such us the soft-reset so we should update to the latest IMHO. Is there any reason not to?

[hiviah]

It's the exactly same version that is used for normal firmware (it's a symlink). So it's either 1.8.0 or 1.8.1.

[tsusanka]

Let's test this when it is in Suite, that means after trezor/trezor-suite#2338 is implemented.