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raspberrypi
FLASH_BLOCK_SIZE macro conflicts with CYW43 driver
The Pico SDK defines a FLASH_BLOCK_SIZE macro in src/rp2_common/hardware_flash/include/hardware/flash.h. The CYW43 driver defines its own FLASH_BLOCK_SIZE macro in src/cyw43_ll.c. When enabling USB MSC on the Pico W, this conflict prevents compilation.
A trivial rename of the FLASH_BLOCK_SIZE macro in the pico-sdk codebase resolves the issue. PR incoming!
can you paste the error; not sure how/why cyw43_ll.c would end up including flash.h even in that case?
The CYW43 driver doesn't include flash.h, it just happens to define its own macro called FLASH_BLOCK_SIZE. So when you enable USB MSC on the Pico W, there are two entirely unrelated parts of the codebase (the CYW43 driver, and the flash driver) which both define a macro FLASH_BLOCK_SIZE for their own purposes. This results in a redefinition error, and the macro in the Pico SDK seemed like the easier one to rename :)
/Users/ipd21/dev/micropython/lib/cyw43-driver/src/cyw43_ll.c:56: error: "FLASH_BLOCK_SIZE" redefined [-Werror]
56 | #define FLASH_BLOCK_SIZE (512)
|
In file included from /Users/ipd21/dev/micropython/ports/rp2/mpconfigport.h:35,
from /Users/ipd21/dev/micropython/py/mpconfig.h:62,
from /Users/ipd21/dev/micropython/ports/rp2/cyw43_configport.h:30,
from /Users/ipd21/dev/micropython/lib/cyw43-driver/src/cyw43_config.h:38,
from /Users/ipd21/dev/micropython/lib/cyw43-driver/src/cyw43_ll.c:40:
/Users/ipd21/dev/micropython/lib/pico-sdk/src/rp2_common/hardware_flash/include/hardware/flash.h:43: note: this is the location of the previous definition
43 | #define FLASH_BLOCK_SIZE (1u << 16)
The CYW43 driver doesn't include flash.h, it just happens to define its own macro called FLASH_BLOCK_SIZE. So when you enable USB MSC on the Pico W, there are two entirely unrelated parts of the codebase (the CYW43 driver, and the flash driver) which both define a macro FLASH_BLOCK_SIZE for their own purposes. This results in a redefinition error, and the macro in the Pico SDK seemed like the easier one to rename :)
You misunderstand how redefinition errors work. For the error to happen, the cyw43 driver would have to have included flash.h. This happens because of this:
https://github.com/micropython/micropython/blob/5bf3765631e645412dbd62a616cfdadeca5ea0c3/ports/rp2/mpconfigport.h#L35
Would have been good to know this was MicroPython to start with; anyways. this would be a backwards incompatible change here, we will need to fix it in either MicroPython or cyw43_driver
Ah good, thanks very much for the additional digging here. In that case I'll close my PR and leave this one with you. Please let me know if there's anything useful I can contribute to the fix. For now, I will continue to use a patched version of the Pico SDK with that macro renamed so that it actually compiles. Thanks!
FLASH_BLOCK_SIZE has been renamed to CYW43_FLASH_BLOCK_SIZE, so I don't think there's anything to do here. Lots of "base ports" define FLASH_BLOCK_SIZE, so I think it's reasonable. Will close if no one disagrees.
That's great - if the macro has been renamed in the CYW43 driver then that entirely resolves the conflict. Please feel free to close. Thanks!