CP build fails when including Pico SDK XIP cache maintenance header

[eightycc]

CircuitPython version and board name

Building any RP2350-based raspberrypi with current top of `main`.

This is *not* a 9.2.5 regression.

Code/REPL

n/a

Behavior

n/a

Description

Including the header sdk/src/rp2_common/hardware_xip_cache/include/hardware/xip_cache.h results in:

In file included from common-hal/picodvi/Framebuffer_RP2350.c:42:
./sdk/src/rp2_common/hardware_xip_cache/include/hardware/xip_cache.h:67:5: error: "PICO_RP2040" is not defined, evaluates to 0 [-Werror=undef]
   67 | #if PICO_RP2040
      |     ^~~~~~~~~~~
./sdk/src/rp2_common/hardware_xip_cache/include/hardware/xip_cache.h:74:5: error: "PICO_RP2040" is not defined, evaluates to 0 [-Werror=undef]
   74 | #if PICO_RP2040
      |     ^~~~~~~~~~~
./sdk/src/rp2_common/hardware_xip_cache/include/hardware/xip_cache.h:180:6: error: "PICO_RP2040" is not defined, evaluates to 0 [-Werror=undef]
  180 | #if !PICO_RP2040 || PICO_COMBINED_DOCS
      |      ^~~~~~~~~~~

Additional information

The root cause of these errors is misuse of the PICO_RP2040 and PICO_RP2350 macros in CP. The Pico SDK, currently at version 2.1.1, expects these macros to always be defined. For an RP2040 target PICO_RP2040=1 and PICO_RP2350=0. Likewise, for an RP2350 target PICO_RP2040=0 and PICO_RP2350=1.

Unfortunately, there are a few places where Pico SDK 2.1.1 overlooked updating its use of these macros, resulting in an un-bootable UF2 file when building CP with CP's usage corrected. See: raspberrypi/pico-sdk#2356 . This pull has been merged into the Pico SDK develop branch and is scheduled for inclusion in 2.1.2.

I'm holding the CP pull in my repo here: https://github.com/eightycc/circuitpython/tree/fix-defines . Once Pico SDK 2.1.2 is released I'll submit a pull to update the SDK version as well as the pull for this issue.