Merge #19368 #19529 #19531

19368: debug: add DEBUG_BREAKPOINT() macro, set breakpoint on failed assertion r=benpicco a=benpicco



19529: cpu/stm32/periph/dac: optimize setting DAC r=benpicco a=Enoch247

### Contribution description

The current implmentation right shifted the 16 bit value passed into `dac_set()` down to the 12 bits that the DAC is actually capable of. This patch drops the shift and instead writes the 16 bit value to the DAC's left aligned 12 bit wide data holding register.


### Testing procedure

do something like:
``` c
#include "perip/dac.h"

int main(void)
{
    dac_set(DAC_LINE(0), 0xffff/2);
    return 0;
}
```
- observe DAC's output is half of vref


### Issues/PRs references

- none known


19531: tests/unittests: allow passing `UNIT_TESTS` via env r=benpicco a=kaspar030



Co-authored-by: Benjamin Valentin <benpicco@beuth-hochschule.de>
Co-authored-by: Joshua DeWeese <jdeweese@primecontrols.com>
Co-authored-by: Kaspar Schleiser <kaspar@schleiser.de>

core/lib/assert.c

@@ -18,6 +18,7 @@
 #include "assert.h"
 #include "architecture.h"
 #include "cpu.h"
+#include "debug.h"
 #include "panic.h"
 #if IS_USED(MODULE_BACKTRACE)
 #include "backtrace.h"
@@ -30,6 +31,7 @@ __NORETURN void _assert_failure(const char *file, unsigned line)
     printf("failed assertion. Backtrace:\n");
     backtrace_print();
 #endif
+    DEBUG_BREAKPOINT(1);
     core_panic(PANIC_ASSERT_FAIL, "FAILED ASSERTION.");
 }
 
@@ -39,6 +41,7 @@ __NORETURN void _assert_panic(void)
 #if IS_USED(MODULE_BACKTRACE)
     backtrace_print();
 #endif
+    DEBUG_BREAKPOINT(1);
     core_panic(PANIC_ASSERT_FAIL, "FAILED ASSERTION.");
 }
 

core/lib/include/debug.h

@@ -59,6 +59,27 @@ extern "C" {
 #define DEBUG_PRINT(...) printf(__VA_ARGS__)
 #endif
 
+/**
+ * @def DEBUG_BREAKPOINT
+ *
+ * @brief Set a debug breakpoint
+ *
+ * When `DEVELHELP` is enabled, this traps the CPU and allows to debug the
+ * program with e.g. `gdb`.
+ * Without `DEVELHELP` this turns into a no-op.
+ *
+ * @warning     If no Debugger is attached, the CPU might get stuck here
+ *              and consume a lot of power until reset.
+ *
+ * @param val   Breakpoint context for debugger, usually ignored.
+ */
+#ifdef DEVELHELP
+#include "architecture.h"
+#define DEBUG_BREAKPOINT(val)   ARCHITECTURE_BREAKPOINT(val)
+#else
+#define DEBUG_BREAKPOINT(val)   (void)0
+#endif
+
 /**
  * @name Debugging defines
  * @{

cpu/cortexm_common/include/architecture_arch.h

@@ -26,7 +26,8 @@ extern "C" {
 
 /* Doc is provided centrally in architecture.h, hide this from Doxygen */
 #ifndef DOXYGEN
-#define ARCHITECTURE_WORD_BITS      (32U)
+#define ARCHITECTURE_WORD_BITS          (32U)
+#define ARCHITECTURE_BREAKPOINT(value)  __BKPT(value)
 #endif /* DOXYGEN */
 
 #ifdef __cplusplus

cpu/native/include/architecture_arch.h

@@ -24,9 +24,17 @@
 extern "C" {
 #endif
 
+/**
+ * @brief raise SIGTRAP
+ *
+ *        We must not include signal.h directly into RIOT application namespace.
+ */
+void native_breakpoint(void);
+
 /* Doc is provided centrally in architecture.h, hide this from Doxygen */
 #ifndef DOXYGEN
 #define ARCHITECTURE_WORD_BITS      (32U)
+#define ARCHITECTURE_BREAKPOINT(v)  native_breakpoint()
 #endif /* DOXYGEN */
 
 #ifdef __cplusplus

cpu/native/native_cpu.c

@@ -99,6 +99,11 @@ int thread_isr_stack_usage(void)
     return -1;
 }
 
+void native_breakpoint(void)
+{
+    raise(SIGTRAP);
+}
+
 static inline void *align_stack(uintptr_t start, int *stacksize)
 {
     const size_t alignment = sizeof(uintptr_t);

cpu/stm32/periph/dac.c

@@ -73,18 +73,15 @@ void dac_set(dac_t line, uint16_t value)
 {
     assert(line < DAC_NUMOF);
 
-    /* scale set value to 12-bit */
-    value = (value >> 4);
-
-#ifdef DAC_DHR12R2_DACC2DHR
+#ifdef DAC_DHR12L2_DACC2DHR
     if (dac_config[line].chan & 0x01) {
-        dev(line)->DHR12R2 = value;
+        dev(line)->DHR12L2 = value;
     }
     else {
-        dev(line)->DHR12R1 = value;
+        dev(line)->DHR12L1 = value;
     }
 #else
-    dev(line)->DHR12R1 = value;
+    dev(line)->DHR12L1 = value;
 #endif
 }
 

sys/include/architecture.h

@@ -33,6 +33,19 @@
 extern "C" {
 #endif
 
+/**
+ * @brief   Set a breakpoint
+ * @warning         If no Debugger is attached, the CPU might get stuck here
+ *                  and consume a lot of power until reset.
+ * @param[in] value Context value for debugger, usually ignored.
+ */
+#ifndef ARCHITECTURE_BREAKPOINT
+/* If no breakpoint instruction is defined, busy wait for debugger
+ * to attach and break to ease backtrace
+ */
+#define ARCHITECTURE_BREAKPOINT(value)  do {} while (1)
+#endif
+
 /* Provide doxygen doc centrally, instead of in every architecture_arch.h */
 #ifdef DOXYGEN
 /**

tests/unittests/Makefile

@@ -3,12 +3,14 @@ include ../Makefile.tests_common
 
 USEMODULE += embunit
 
-ifeq (, $(filter tests-%, $(MAKECMDGOALS)))
-  # the $(dir) Makefile function leaves a trailing slash after the directory
-  # name, therefore we use patsubst instead.
-  UNIT_TESTS := $(patsubst %/Makefile,%,$(wildcard tests-*/Makefile))
-else
-  UNIT_TESTS := $(filter tests-%, $(MAKECMDGOALS))
+ifeq (, $(UNIT_TESTS))
+  ifeq (, $(filter tests-%, $(MAKECMDGOALS)))
+    # the $(dir) Makefile function leaves a trailing slash after the directory
+    # name, therefore we use patsubst instead.
+    UNIT_TESTS := $(patsubst %/Makefile,%,$(wildcard tests-*/Makefile))
+  else
+    UNIT_TESTS := $(filter tests-%, $(MAKECMDGOALS))
+  endif
 endif
 
 DISABLE_MODULE += auto_init auto_init_%