Fix pioasm build with GCC 15 by forcing pthread init

.clang-format

@@ -0,0 +1,2 @@
+AllowShortFunctionsOnASingleLine: None
+BasedOnStyle: Google

.clang-tidy

@@ -0,0 +1,26 @@
+Checks: >
+  -*,
+  clang-analyzer-*,
+  bugprone-*,
+  performance-*,
+  portability-*,
+  misc-*,
+  readability-*,
+  modernize-*,
+  -clang-analyzer-alpha*,
+  -bugprone-easily-swappable-parameters,
+  -bugprone-exception-escape,
+  -bugprone-narrowing-conversions,
+  -bugprone-reserved-identifier,
+  -misc-include-cleaner,
+  -modernize-avoid-c-arrays,
+  -modernize-use-auto,
+  -modernize-use-nodiscard,
+  -modernize-use-trailing-return-type,
+  -readability-function-cognitive-complexity,
+  -readability-identifier-length,
+  -readability-implicit-bool-conversion,
+  -readability-magic-numbers
+WarningsAsErrors: ''
+HeaderFilterRegex: '.*'
+FormatStyle: file

.clangd-bin

@@ -0,0 +1 @@
+/stuff/tools/llvm/ATfE-21.1.1/bin/clangd

docker-compose.yml

@@ -0,0 +1,19 @@
+version: "3.9"
+
+services:
+  pico2:
+    image: pico2:25.10
+    user: "${UID:-1000}:${GID:-1000}"
+    working_dir: /stuff/work/pico-sdk
+    environment:
+      USER: uzleo
+      HOME: /home/uzleo
+    entrypoint: ["/usr/bin/env", "fish"]
+    volumes:
+      - /stuff/work:/stuff/work
+      - /stuff/tools:/stuff/tools
+      - /home/uzleo:/home/uzleo
+      - /etc/passwd:/etc/passwd:ro
+      - /etc/group:/etc/group:ro
+    stdin_open: true
+    tty: true

examples/CMakeLists.txt

@@ -0,0 +1,60 @@
+cmake_minimum_required(VERSION 3.30)
+
+include(../pico_sdk_init.cmake)
+
+set(CMAKE_CXX_SCAN_FOR_MODULES ON)
+
+project(examples C CXX ASM)
+
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+pico_sdk_init()
+
+if (DEFINED PICO_COMPILER_SYSROOT)
+    set(LIBCXX_STD_MODULE_DIR "${PICO_COMPILER_SYSROOT}/share/libc++/v1")
+    set(LIBCXX_STD_MODULE "${LIBCXX_STD_MODULE_DIR}/std.cppm")
+else()
+    message(FATAL_ERROR "PICO_COMPILER_SYSROOT is not set; cannot locate libc++ std module")
+endif()
+
+if (NOT CMAKE_CXX_COMPILER_CLANG_SCAN_DEPS)
+    find_program(CMAKE_CXX_COMPILER_CLANG_SCAN_DEPS
+            NAMES clang-scan-deps clang-scan-deps-21 clang-scan-deps-20
+            PATHS ${PICO_TOOLCHAIN_PATH}/bin /usr/bin)
+endif()
+
+add_executable(led_blink
+        led_blink_raw.cpp
+)
+target_compile_features(led_blink PRIVATE cxx_std_26)
+target_compile_options(led_blink PRIVATE
+  $<$<COMPILE_LANG_AND_ID:C,Clang,AppleClang>:-Weverything -Wno-c++98-compat>
+  $<$<COMPILE_LANG_AND_ID:CXX,Clang,AppleClang>:-Weverything -Wno-c++98-compat>
+)
+target_link_libraries(led_blink pico_stdlib)
+pico_set_printf_implementation(led_blink none)
+pico_enable_stdio_usb(led_blink 1)
+pico_enable_stdio_uart(led_blink 0)
+
+if (PICO_CLIB STREQUAL "llvm_libc")
+    # libdummyhost provides stdio symbols for llvm-libc runtimes.
+    target_link_options(led_blink PRIVATE -ldummyhost)
+endif()
+
+target_sources(led_blink PRIVATE
+        FILE_SET cxx_modules TYPE CXX_MODULES
+        BASE_DIRS ${CMAKE_CURRENT_LIST_DIR}/sdk
+        FILES sdk/hw/hw.cppm
+)
+
+if (EXISTS "${LIBCXX_STD_MODULE}")
+    target_sources(led_blink PRIVATE
+            FILE_SET libcxx_modules TYPE CXX_MODULES
+            BASE_DIRS "${LIBCXX_STD_MODULE_DIR}"
+            FILES "${LIBCXX_STD_MODULE}"
+    )
+else()
+    message(FATAL_ERROR "libc++ std module not found at ${LIBCXX_STD_MODULE}; import std will fail")
+endif()
+
+pico_add_extra_outputs(led_blink)

examples/README.md

@@ -0,0 +1,18 @@
+# Building without USB/stdio using LLVM Embedded Toolchain
+
+For bare-metal targets that don’t need USB stdio, configure with the LLVM Embedded Toolchain sysroot and skip picotool/UF2. Example (building `led_blink` on pico2):
+```
+rm -rf build
+cmake -G Ninja -S examples -B build -DPICO_BOARD=pico2 \
+  -DPICO_COMPILER=pico_arm_cortex_m33_clang \
+  -DPICO_TOOLCHAIN_PATH=/stuff/tools/llvm/ATfE-21.1.1 \
+  -DPICO_COMPILER_SYSROOT=/stuff/tools/llvm/ATfE-21.1.1/lib/clang-runtimes/arm-none-eabi/armv8m.main_hard_fp_exn_rtti_unaligned_size \
+  -DPICO_NO_PICOTOOL=1 \
+  -DCMAKE_TRY_COMPILE_PLATFORM_VARIABLES="PICO_COMPILER_SYSROOT;PICO_CLANG_RUNTIMES;PICO_CLIB"  \
+  -DCMAKE_C_STANDARD_INCLUDE_DIRECTORIES="/stuff/tools/llvm/ATfE-21.1.1/lib/clang-runtimes/arm-none-eabi/include/" \
+  -DCMAKE_CXX_STANDARD_INCLUDE_DIRECTORIES="/stuff/tools/llvm/ATfE-21.1.1/lib/clang-runtimes/arm-none-eabi/include/c++/v1/;/stuff/tools/llvm/ATfE-21.1.1/lib/clang-runtimes/arm-none-eabi/include/"
+
+cmake --build build
+```
+
+Adjust paths for your toolchain install; some ATfE versions add a `_size` suffix to the runtime directory. Re-enable picotool/USB stdio if needed.

examples/led_blink_raw.cpp

@@ -0,0 +1,12 @@
+
+import pico.hw;
+
+auto main() -> int {
+  pico::hw::InitializeBoard();
+
+  pico::hw::InitializeLedPin();
+  while (true) {
+    pico::hw::ToggleLed();
+    pico::hw::BusyDelay(12000000);
+  }
+}

examples/sdk/hw/hw.cppm

@@ -0,0 +1,70 @@
+
+module;
+
+#include "hardware/structs/io_bank0.h"
+#include "hardware/structs/padsbank0.h"
+#include "hardware/structs/sio.h"
+#include "pico/platform.h"
+#include "pico/stdio.h"
+
+export module pico.hw;
+
+import std;
+
+namespace pico::hw {
+
+export auto InitializeBoard() -> void;
+export auto InitializeLedPin() -> void;
+export auto BusyDelay(std::uint32_t cycles) -> void;
+export auto ToggleLed() -> void;
+
+}  // namespace pico::hw
+
+namespace {
+
+std::uint8_t constexpr kLedPin{25};
+
+template <typename T = std::bitset<32>>
+  requires(std::unsigned_integral<T> or std::same_as<T, std::bitset<32>>)
+consteval auto GetLedMask() -> T {
+  std::bitset<32> led_mask{};
+  led_mask.set(kLedPin);
+
+  if constexpr (std::is_same_v<T, std::bitset<32>>) {
+    return led_mask;
+  }
+
+  return static_cast<T>(led_mask.to_ulong());
+}
+
+}  // namespace
+
+namespace pico::hw {
+
+auto InitializeBoard() -> void {
+  stdio_init_all();
+}
+
+auto InitializeLedPin() -> void {
+  // Configure the pad for push-pull output: 4 mA drive, Schmitt enabled, no
+  // pulls.
+  padsbank0_hw->io[kLedPin] =
+      (PADS_BANK0_GPIO25_DRIVE_VALUE_4MA << PADS_BANK0_GPIO25_DRIVE_LSB) |
+      PADS_BANK0_GPIO25_SCHMITT_BITS;
+
+  // Route the pin to the SIO peripheral so we can drive it directly.
+  io_bank0_hw->io[kLedPin].ctrl = GPIO_FUNC_SIO;
+
+  // Enable output on the pin via SIO.
+  sio_hw->gpio_oe_set = GetLedMask<std::uint32_t>();
+}
+
+auto BusyDelay(std::uint32_t cycles) -> void {
+  busy_wait_at_least_cycles(cycles);
+}
+
+auto ToggleLed() -> void {
+  sio_hw->gpio_togl = GetLedMask<std::uint32_t>();
+}
+
+}  // namespace pico::hw

src/rp2_common/pico_clib_interface/CMakeLists.txt

@@ -1,6 +1,10 @@
 if (NOT TARGET pico_clib_interface)
     pico_add_library(pico_clib_interface)
 
+    target_sources(pico_clib_interface INTERFACE
+            ${CMAKE_CURRENT_LIST_DIR}/fini_stub.c
+    )
+
     # ---- newlib ----
     pico_add_library(pico_newlib_interface)
 

src/rp2_common/pico_clib_interface/fini_stub.c

@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) 2025 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include "pico.h"
+
+// Bare-metal stub so __libc_fini_array can resolve _fini without pulling in
+// hosted runtime shutdown logic.
+void __weak _fini(void) {}

src/rp2_common/pico_crt0/rp2350/memmap_default.ld

@@ -77,24 +77,26 @@ SECTIONS
 
         . = ALIGN(4);
         /* preinit data */
-        PROVIDE_HIDDEN (__preinit_array_start = .);
+        PROVIDE (__bothinit_array_start = .);
+        PROVIDE (__preinit_array_start = .);
         KEEP(*(SORT(.preinit_array.*)))
         KEEP(*(.preinit_array))
-        PROVIDE_HIDDEN (__preinit_array_end = .);
+        PROVIDE (__preinit_array_end = .);
 
         . = ALIGN(4);
         /* init data */
-        PROVIDE_HIDDEN (__init_array_start = .);
+        PROVIDE (__init_array_start = .);
         KEEP(*(SORT(.init_array.*)))
         KEEP(*(.init_array))
-        PROVIDE_HIDDEN (__init_array_end = .);
+        PROVIDE (__init_array_end = .);
+        PROVIDE (__bothinit_array_end = .);
 
         . = ALIGN(4);
         /* finit data */
-        PROVIDE_HIDDEN (__fini_array_start = .);
+        PROVIDE (__fini_array_start = .);
         *(SORT(.fini_array.*))
         *(.fini_array)
-        PROVIDE_HIDDEN (__fini_array_end = .);
+        PROVIDE (__fini_array_end = .);
 
         *(.eh_frame*)
         . = ALIGN(4);
@@ -299,4 +301,3 @@ SECTIONS
 
     /* todo assert on extra code */
 }
-

src/rp2_common/pico_platform_compiler/include/pico/platform/compiler.h

@@ -27,6 +27,11 @@
 #else
 #define PICO_C_COMPILER_IS_GNU 1
 #endif
+/* Some libc variants (e.g. picolibc/LLVM embedded toolchain) don't provide
+ * __printflike; fall back to the usual GCC-style format attribute. */
+#ifndef __printflike
+#define __printflike(a, b) __attribute__((__format__(printf, a, b)))
+#endif
 #elif defined __ICCARM__
 #ifndef __aligned
 #define __aligned(x)	__attribute__((__aligned__(x)))

tools/pioasm/CMakeLists.txt

@@ -23,6 +23,7 @@ add_executable(pioasm
         gen/lexer.cpp
         gen/parser.cpp
 )
+target_compile_definitions(pioasm PRIVATE _GTHREAD_USE_COND_INIT_FUNC)
 
 target_sources(pioasm PRIVATE c_sdk_output.cpp)
 target_sources(pioasm PRIVATE python_output.cpp)