chore: import upstream snapshot with attribution

examples/system/esp_trace/components/ext_trace_lib/include/esp_trace_freertos_impl.h

@@ -0,0 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include "trace_FreeRTOS.h"

examples/system/esp_trace/components/ext_trace_lib/include/trace_FreeRTOS.h

@@ -0,0 +1,68 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+/*
+ * External Trace Library - FreeRTOS trace hooks
+ *
+ * This header is pulled in (via esp_trace_freertos_impl.h) from FreeRTOSConfig.h
+ * Do NOT include any FreeRTOS header here — keep this file restricted to:
+ *   - forward declarations of the C functions called by the macros below,
+ *   - the trace*() macro definitions themselves.
+ *
+ * Macros are allowed to reference FreeRTOS identifiers (pxTCB, xTicksToWait, ...)
+ * by name — they are resolved later, when the macro is expanded inside the
+ * FreeRTOS kernel .c files where those names are already in scope.
+ *
+ * Only the trace*() macros this example actually hooks are defined here.
+ * Anything left undefined falls back to FreeRTOS's own empty default (see
+ * the #ifndef guards in freertos/FreeRTOS.h).
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Forward declaration so we can pass an encoder pointer from the adapter to
+ * init_trace_lib() without pulling in esp_trace_port_encoder.h. */
+typedef struct esp_trace_encoder esp_trace_encoder_t;
+
+void init_trace_lib(esp_trace_encoder_t *enc);
+void trace_lib_start(void);
+void trace_lib_stop(void);
+
+/* Hook implementations — defined in trace_FreeRTOS.c.
+ * Kept void*-typed to avoid depending on FreeRTOS types in this header. */
+void trace_lib_task_switched_in(void);
+void trace_lib_task_create(void *pxNewTCB);
+void trace_lib_isr_enter(uint32_t irq);
+void trace_lib_isr_exit(void);
+void trace_lib_isr_exit_to_scheduler(void);
+void trace_lib_queue_send(void *pxQueue);
+void trace_lib_queue_receive(void *pxQueue);
+void trace_lib_queue_create(void *pxNewQueue);
+
+#ifdef __cplusplus
+}
+#endif
+
+/* ------------------------------------------------------------------ *
+ *  Active hooks (forwarded to trace_FreeRTOS.c)
+ * ------------------------------------------------------------------ */
+#define traceTASK_SWITCHED_IN()                          trace_lib_task_switched_in()
+#define traceTASK_CREATE(pxNewTCB)                       trace_lib_task_create(pxNewTCB)
+#define traceISR_ENTER(n)                                trace_lib_isr_enter(n)
+#define traceISR_EXIT()                                  trace_lib_isr_exit()
+#define traceISR_EXIT_TO_SCHEDULER()                     trace_lib_isr_exit_to_scheduler()
+#define traceQUEUE_SEND(pxQueue)                         trace_lib_queue_send(pxQueue)
+#define traceQUEUE_RECEIVE(pxQueue)                      trace_lib_queue_receive(pxQueue)
+#define traceQUEUE_CREATE(pxNewQueue)                    trace_lib_queue_create(pxNewQueue)
+
+/* All other trace*() macros fall back to FreeRTOS's default empty defines
+ * (#ifndef ... #define ... empty in freertos/FreeRTOS.h); no need to list
+ * them here. Add a mapping above when you want to hook one. */