The goal is to allow Trezor 1 to create TPoS contracts for Stakenet.
Last year, Stakenet introduced a hard-fork [1] to change the way TPoS contracts
are created, instead of a custom signature method, now it works with the
output from the signMessage method, while this works for Trezor T, it doesn't
work for Trezor 1 due to the 80 bytes limit on the OP_RETURN output while
Stakenet allows up to 150 bytes [2], in a gitter discussion [3] we concluded that
the change should be fine.
The hard-fork was introduced because we couldn't got our TPoS contracts PR accepted [4],
the OP_RETURN still contains the same data, its just stored in a different way:
- The TPoS address, where the coins to stake are stored, and where rewards are received.
- The merchant address, where the merchant receives its commission.
- The contract commission.
- The TPoS collateral signature (this is what uses the signMessage now).
At last, there is an example transaction creating a TPoS contract [5].
[1]: https://github.com/X9Developers/XSN/pull/154
[2]: https://github.com/X9Developers/XSN/blob/master/src/script/standard.h#L34
[3]: https://gitter.im/trezor/community?at=6064c41e940f1d555e2ea670
[4]: https://github.com/trezor/trezor-firmware/pull/140
[5]: https://xsnexplorer.io/transactions/858feb31097501cf68d698cde104cf778ec51ff3668e943404b549a5dd2f5792
The original wait_layout was unreliable, because there are no guarantees
re order of arrival of the respective events. Still, TT's event handling
is basically deterministic, so as long as the host sent its messages
close enough to each other, the order worked out.
This is no longer the case with the introduction of loop.spawn: TT's
behavior is still deterministic, but now ButtonAck is processed *before*
the corresponding wait_layout, so the waiting side waits forever.
In the new process, the host must first register to receive layout
events, and then receives all of them (so the number of calls to
wait_layout must match the number of layout changes).
DebugLinkWatchLayout message must be version-gated, because of an
unfortunate collection of bugs in previous versions wrt unknown message
handling; and this interests us because upgrade-tests are using
wait_layout feature.
