Add cosmo rev B

[labbott]

No description provided.

[labbott]

Need to check this

[mkeeter]

Looks correct to me:

[hawkw]

some nitpicks, but no concerns from me!

[hawkw]

take it or leave it: could also do

Suggested change

	if board != "cosmo-a" && board != "cosmo-b" {
	if !matches!(board, "cosmo-a" | "cosmo-b") {

(or maybe if let would work too?)

[labbott]

There's str vs String nonsense here

 error[E0308]: mismatched types
  --> drv/cosmo-seq-server/build.rs:18:25
   |
18 |     if !matches!(board, "cosmo-a" | "cosmo-b") {
   |                  -----  ^^^^^^^^^ expected `String`, found `&str`
   |                  |
   |                  this expression has type `String`

error[E0308]: mismatched types
  --> drv/cosmo-seq-server/build.rs:18:37
   |
18 |     if !matches!(board, "cosmo-a" | "cosmo-b") {
   |                  -----              ^^^^^^^^^ expected `String`, found `&str`
   |                  |
   |                  this expression has type `String`

[mkeeter]

This comment is now out of date

[mkeeter]

Vibes: I would write this using a runtime conditional, i.e.

if cfg!(target_board = "cosmo-a") {
    // ...
} else {
    // ...
}

That way, all of the code is checked (and you can remove the #[allow(unused_mut)]), but the compiler will almost certainly optimize it out.