error.txt

   Compiling embassy-macros v0.1.0 (https://github.com/lulf/embassy.git?rev=5bb3c71c597e46267f37ce734866f2db8af21649#5bb3c71c)
error[E0425]: cannot find function `__basepri_r` in module `crate::asm::inline`
 --> /home/jim/.cargo/registry/src/github.com-1ecc6299db9ec823/cortex-m-0.7.3/src/register/basepri.rs:6:15
  |
6 |     call_asm!(__basepri_r() -> u8)
  |               ^^^^^^^^^^^ not found in `crate::asm::inline`

error[E0425]: cannot find function `__basepri_w` in module `crate::asm::inline`
  --> /home/jim/.cargo/registry/src/github.com-1ecc6299db9ec823/cortex-m-0.7.3/src/register/basepri.rs:22:19
   |
22 |         call_asm!(__basepri_w(basepri: u8));
   |                   ^^^^^^^^^^^ not found in `crate::asm::inline`

error[E0425]: cannot find function `__basepri_max` in module `crate::asm::inline`
  --> /home/jim/.cargo/registry/src/github.com-1ecc6299db9ec823/cortex-m-0.7.3/src/register/basepri_max.rs:19:19
   |
19 |         call_asm!(__basepri_max(basepri: u8));
   |                   ^^^^^^^^^^^^^ not found in `crate::asm::inline`

error[E0425]: cannot find function `__faultmask_r` in module `crate::asm::inline`
  --> /home/jim/.cargo/registry/src/github.com-1ecc6299db9ec823/cortex-m-0.7.3/src/register/faultmask.rs:29:28
   |
29 |     let r: u32 = call_asm!(__faultmask_r() -> u32);
   |                            ^^^^^^^^^^^^^ not found in `crate::asm::inline`

error: invalid register `r0`: unknown register
   --> /home/jim/.cargo/registry/src/github.com-1ecc6299db9ec823/cortex-m-0.7.3/src/../asm/inline.rs:188:24
    |
188 |     asm!("bkpt #0xab", inout("r0") nr, in("r1") arg);
    |                        ^^^^^^^^^^^^^^

error: invalid register `r1`: unknown register
   --> /home/jim/.cargo/registry/src/github.com-1ecc6299db9ec823/cortex-m-0.7.3/src/../asm/inline.rs:188:40
    |
188 |     asm!("bkpt #0xab", inout("r0") nr, in("r1") arg);
    |                                        ^^^^^^^^^^^^

For more information about this error, try `rustc --explain E0425`.
error: could not compile `cortex-m` due to 6 previous errors
warning: build failed, waiting for other jobs to finish...
error: build failed

This fixes it:

rustup target add thumbv6m-none-eabi