raspberrypi: stop pulling newlib's time zone code into RP2040 builds - #11379
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The SDK's pico_localtime_r() and pico_mktime() are weak wrappers around newlib's localtime_r() and mktime(). rtc.RTC uses them through aon_timer on RP2040, and they bring tzset, getenv and the scanf code along: 6496 bytes of flash on raspberry_pi_pico. CircuitPython has the same calendar arithmetic in shared/timeutils, and newlib runs without a TZ here, so both compute UTC. Define the two SDK hooks on top of timeutils. RP2350 keeps its time in the powman timer and never called them.
dhalbert
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Sep 14, 2026
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OH, neat! This is a big savings!
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The SDK's
pico_localtime_r()andpico_mktime()are weak wrappers around newlib'slocaltime_r()andmktime().rtc.RTCuses them through aon_timer on RP2040, and they bring tzset, getenv and the scanf code along.CircuitPython has the same calendar arithmetic in
shared/timeutils, and newlib runs without a TZ here, so both compute UTC.This PR defines the two SDK hooks on top of timeutils.
Flash on raspberry_pi_pico: 981080 -> 974584, saved 6.5 kB.