* nrf52_lto: fix variant LTO exclusion (match srcnode, not mirrored path) + post-link guard
The CI-fix follow-up in #10829 anchored _is_board_variant() to
<PROJECT_DIR>/variants/ using node.get_abspath() -- but build middleware
receives nodes from the SCons variant-dir mirror, whose abspath is
$BUILD_DIR/variants/.../variant.cpp. The anchor never matched, so the
variant silently went back into whole-image LTO: the shipped ELF has
initVariant() resolved to the core's weak empty stub (bare `bx lr`),
PIN_3V3_EN is never driven, and the SX1262 probe fails with
CHIP_NOT_FOUND again -- while the build stays green, because the
post-link guard only checked IRQ handlers.
Fix: match against node.srcnode().get_abspath(), which undoes the
variant-dir mirror (the same trick piobuild.py uses for middleware
pattern matching).
Add a second post-link guard so this failure mode is a red build, not a
field failure: the linked variant.cpp.o must contain no .gnu.lto_*
sections (proves the -fno-lto recompile fired), and any override the
object defines strong (initVariant) must resolve strong in the ELF.
Verified both ways on nrf52_promicro_diy_tcxo: clean build is green with
T _Z11initVariantv and a real initVariant body in the ELF; re-breaking
the matcher turns the build FAILED with both guard checks firing.
clod helped a lot
* address comments
* nrf52_lto: defer variant CCFLAGS so APP_VERSION is present
The variant -fno-lto recompile snapshotted projenv["CCFLAGS"] inside the
build middleware, which fires during $BUILD_SCRIPT. But -DAPP_VERSION... is
appended to projenv by bin/platformio-custom.py, an unprefixed extra_script
that PlatformIO runs as a POST script -- after the middleware. The frozen
override therefore lacked APP_VERSION, so recompiling any board variant whose
variant.cpp includes configuration.h (rak_wismeshtag via sleep.h,
seeed_xiao_nrf52840_kit, seeed_mesh_tracker_X1) failed with
'APP_VERSION must be set by the build environment'.
Defer the CCFLAGS read to a callable construction variable: SCons invokes it
during command substitution, after every SConscript (post-scripts included),
so projenv now carries the version flags. -fno-lto is appended last so it
still wins over the inherited -flto.
Verified clean builds of rak_wismeshtag, seeed_xiao_nrf52840_kit, and rak4631
(regression) -- all green with the variant guard reporting the board variant
kept out of LTO.
---------
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
* Add LTO support for nrf52840 while preserving interrupt handlers
* nrf52840: enable whole-image LTO on all targets via nrf52_base
Moves -flto + the nrf52_lto.py exclusion middleware from the rak4631 env
(771018ca8) up to [nrf52_base], so every nrf52840 target inherits it.
nrf52_lto.py keeps the interrupt handlers out of LTO (framework core +
TinyUSB USBD_IRQHandler) -- they're referenced only from the asm vector
table, so whole-program LTO would otherwise drop them and the chip hangs.
HW-validated: RAK4631 (SX1262, -60KB) and muzi-base (LR1121) both boot and
init their radios. Build-verified on canaryone (fresh board, base-inherited).
Caveat: the RAK "1-Watt" variant's radio does not tolerate global-LTO
(SX126x init fails); it shares the rak4631 binary, so keep that hardware on
src-only or split it into a separate target.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* nrf52840: move -fmerge-all-constants to nrf52_base (all targets)
It had been trialed on rak4631 only; it's a general image-wide flag (the
same one stm32 uses globally, ~0.7KB), so move it up to [nrf52_base] next
to -flto so every nrf52840 target gets it instead of just rak4631.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* nrf52_lto.py: normalize path separators for Windows (Copilot review)
get_abspath() returns backslash-separated paths on Windows, so the
"/FrameworkArduino/" / "/cores/nRF5/" substring matches would miss and the
ISR-owning objects would still be LTO'd -> hang on first IRQ. Replace
backslashes with forward slashes before matching. No-op on macOS/Linux.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* Fix directory handling for LTO
* Add post-link guard to check for dropped ISR handlers in nrf52 LTO
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: Jason P <applewiz@mac.com>
