CI: Add pendsv build patch from upstream.

boards/pendsv_build.patch

@@ -0,0 +1,186 @@
+From 71df9d0636c8b0b95ab009f82bde7d5b970835ec Mon Sep 17 00:00:00 2001
+From: Angus Gratton <[email protected]>
+Date: Tue, 11 Feb 2025 16:42:03 +1100
+Subject: [PATCH 1/3] rp2: Fix build failure if threads are disabled.
+
+Regression in 3af006ef meant that pendsv.c no longer compiled if threads
+were disabled in the build config. Add an implementation based on the
+earlier one (simple counter) for the non-threads case.
+
+It seems like with the current usage patterns there's no need for the
+counter to be incremented/decremented atomically on a single core config.
+
+This work was funded through GitHub Sponsors.
+
+Signed-off-by: Angus Gratton <[email protected]>
+---
+ ports/rp2/pendsv.c | 49 +++++++++++++++++++++++++++++++++++++++++++---
+ 1 file changed, 46 insertions(+), 3 deletions(-)
+
+diff --git a/ports/rp2/pendsv.c b/ports/rp2/pendsv.c
+index 4ba1e81604b0f..2c086f89429be 100644
+--- a/ports/rp2/pendsv.c
++++ b/ports/rp2/pendsv.c
+@@ -43,10 +43,14 @@
+
+ static pendsv_dispatch_t pendsv_dispatch_table[PENDSV_DISPATCH_NUM_SLOTS];
+
++static inline void pendsv_resume_run_dispatch(void);
++
+ void PendSV_Handler(void);
+
+-// Using the nowait variant here as softtimer updates PendSV from the loop of mp_wfe_or_timeout(),
+-// where we don't want the CPU event bit to be set.
++#if MICROPY_PY_THREAD
++
++// Important to use a 'nowait' mutex here as softtimer updates PendSV from the
++// loop of mp_wfe_or_timeout(), where we don't want the CPU event bit to be set.
+ static mp_thread_recursive_mutex_t pendsv_mutex;
+
+ void pendsv_init(void) {
+@@ -62,7 +66,40 @@ void pendsv_suspend(void) {
+
+ void pendsv_resume(void) {
+     mp_thread_recursive_mutex_unlock(&pendsv_mutex);
++    pendsv_resume_run_dispatch();
++}
++
++static inline int pendsv_suspend_count(void) {
++    return pendsv_mutex.mutex.enter_count;
++}
++
++#else
++
++// Without threads we don't include any pico-sdk mutex in the build,
++// but also we don't need to worry about cross-thread contention (or
++// races with interrupts that update this counter).
++static int pendsv_lock;
++
++void pendsv_init(void) {
++}
++
++void pendsv_suspend(void) {
++    pendsv_lock++;
++}
++
++void pendsv_resume(void) {
++    assert(pendsv_lock > 0);
++    pendsv_lock--;
++    pendsv_resume_run_dispatch();
++}
+
++static inline int pendsv_suspend_count(void) {
++    return pendsv_lock;
++}
++
++#endif
++
++static inline void pendsv_resume_run_dispatch(void) {
+     // Run pendsv if needed.  Find an entry with a dispatch and call pendsv dispatch
+     // with it.  If pendsv runs it will service all slots.
+     int count = PENDSV_DISPATCH_NUM_SLOTS;
+@@ -76,7 +113,7 @@ void pendsv_resume(void) {
+
+ void pendsv_schedule_dispatch(size_t slot, pendsv_dispatch_t f) {
+     pendsv_dispatch_table[slot] = f;
+-    if (pendsv_mutex.mutex.enter_count == 0) {
++    if (pendsv_suspend_count() == 0) {
+         #if PICO_ARM
+         // There is a race here where other core calls pendsv_suspend() before
+         // ISR can execute, but dispatch will happen later when other core
+@@ -97,6 +134,7 @@ void pendsv_schedule_dispatch(size_t slot, pendsv_dispatch_t f) {
+ // PendSV interrupt handler to perform background processing.
+ void PendSV_Handler(void) {
+
++    #if MICROPY_PY_THREAD
+     if (!mp_thread_recursive_mutex_lock(&pendsv_mutex, 0)) {
+         // Failure here means core 1 holds pendsv_mutex. ISR will
+         // run again after core 1 calls pendsv_resume().
+@@ -104,6 +142,9 @@ void PendSV_Handler(void) {
+     }
+     // Core 0 should not already have locked pendsv_mutex
+     assert(pendsv_mutex.mutex.enter_count == 1);
++    #else
++    assert(pendsv_suspend_count() == 0);
++    #endif
+
+     #if MICROPY_PY_NETWORK_CYW43
+     CYW43_STAT_INC(PENDSV_RUN_COUNT);
+@@ -117,5 +158,7 @@ void PendSV_Handler(void) {
+         }
+     }
+
++    #if MICROPY_PY_THREAD
+     mp_thread_recursive_mutex_unlock(&pendsv_mutex);
++    #endif
+ }
+
+From 516709be88571da0195125c840e772a3ec70fa66 Mon Sep 17 00:00:00 2001
+From: Angus Gratton <[email protected]>
+Date: Tue, 11 Feb 2025 17:44:19 +1100
+Subject: [PATCH 2/3] py/mkrules.cmake: Support passing CFLAGS_EXTRA in
+ environment variable.
+
+This works similarly to the existing support in "bare metal" make ports,
+with the caveat that CMake will only set this value on a clean build and
+will reuse the previous value otherwise.
+
+This is slightly different to the CMake built-in support for CFLAGS,
+as this variable is used when evaluating source files for qstr
+generation, etc.
+
+This work was funded through GitHub Sponsors.
+
+Signed-off-by: Angus Gratton <[email protected]>
+---
+ py/mkrules.cmake | 9 +++++++++
+ 1 file changed, 9 insertions(+)
+
+diff --git a/py/mkrules.cmake b/py/mkrules.cmake
+index 3ee4c4c31aa57..907500dd67534 100644
+--- a/py/mkrules.cmake
++++ b/py/mkrules.cmake
+@@ -53,6 +53,15 @@ foreach(_arg ${MICROPY_CPP_DEF})
+ endforeach()
+ list(APPEND MICROPY_CPP_FLAGS ${MICROPY_CPP_FLAGS_EXTRA})
+
++# Include anything passed in via CFLAGS_EXTRA
++# in both MICROPY_CPP_FLAGS and CMAKE_C_FLAGS
++if(DEFINED ENV{CFLAGS_EXTRA})
++  set(CFLAGS_EXTRA $ENV{CFLAGS_EXTRA})
++  string(APPEND CMAKE_C_FLAGS " ${CFLAGS_EXTRA}")  # ... not a list
++  separate_arguments(CFLAGS_EXTRA)
++  list(APPEND MICROPY_CPP_FLAGS ${CFLAGS_EXTRA})  # ... a list
++endif()
++
+ find_package(Python3 REQUIRED COMPONENTS Interpreter)
+
+ target_sources(${MICROPY_TARGET} PRIVATE
+
+From 17038f806ad6e8ceb497ca60c414af8dc3c8b38e Mon Sep 17 00:00:00 2001
+From: Angus Gratton <[email protected]>
+Date: Tue, 11 Feb 2025 17:46:33 +1100
+Subject: [PATCH 3/3] tools/ci,ports/rp2: Build the W5100S_EVB_PICO board with
+ no threads.
+
+Serves as a build test for a config we don't otherwise support.
+
+Signed-off-by: Angus Gratton <[email protected]>
+---
+ tools/ci.sh | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/tools/ci.sh b/tools/ci.sh
+index ff362efd29e2d..d50af4a0ae2ee 100755
+--- a/tools/ci.sh
++++ b/tools/ci.sh
+@@ -342,7 +342,8 @@ function ci_rp2_build {
+     make ${MAKEOPTS} -C ports/rp2 BOARD=RPI_PICO2 submodules
+     make ${MAKEOPTS} -C ports/rp2 BOARD=RPI_PICO2
+     make ${MAKEOPTS} -C ports/rp2 BOARD=W5100S_EVB_PICO submodules
+-    make ${MAKEOPTS} -C ports/rp2 BOARD=W5100S_EVB_PICO
++    # This build doubles as a build test for disabling threads in the config
++    make ${MAKEOPTS} -C ports/rp2 BOARD=W5100S_EVB_PICO CFLAGS_EXTRA=-DMICROPY_PY_THREAD=0
+
+     # Test building ninaw10 driver and NIC interface.
+     make ${MAKEOPTS} -C ports/rp2 BOARD=ARDUINO_NANO_RP2040_CONNECT submodules

boards/presto/mpconfigboard.h

@@ -32,10 +32,4 @@ int mp_hal_is_pin_reserved(int n);
 #define MICROPY_HW_PSRAM_CS_PIN                 PIMORONI_PRESTO_PSRAM_CS_PIN
 
 #define MICROPY_PY_THREAD                       (0)
-#define MICROPY_GC_SPLIT_HEAP                   (0)
-
-// Hack for pendsv.c using "mp_thread_recursive_mutex_t"
-struct _mp_state_thread_t;
-#include "mpthreadport.h"
-
-typedef recursive_mutex_nowait_t mp_thread_recursive_mutex_t;
+#define MICROPY_GC_SPLIT_HEAP                   (0)

ci/micropython.sh

@@ -47,6 +47,8 @@ function ci_micropython_clone {
     cd "$CI_BUILD_ROOT/micropython/lib/pico-sdk"
     log_inform "HACK: cyw43 stability backport for Pico2 W. See: https://github.com/raspberrypi/pico-sdk/pull/2209"
     git apply "$CI_PROJECT_ROOT/boards/pico2_w_cyw43.patch"
+    log_inform "HACK: fix for pendsv build regression. See: https://github.com/micropython/micropython/pull/16733"
+    git apply "$CI_PROJECT_ROOT/boards/pendsv_build.patch"
     cd "$CI_BUILD_ROOT"
 }