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+# Enabling trace resource in the message_handler_openamp application
+
+The message_handler_openamp application provides support for logging to a trace buffer via the trace entry in the resource table. The following instructions briefly describe one way of enabling the trace resource in the firmware's resource table:
+
+1. Enable building message_handler_openamp with trace buffer support by setting the CMake BOOL cache entry ENABLE_REMOTEPROC_TRACE_BUFFER to ON in the target's CMakeLists.txt
+
+2. Update the target's linker scripts to include an `ethosu_core_trace_buffer` section that is placed in the DRAM as shown in the examples below. The linker-defined symbols for the trace buffer's address and size are later used by the message_handler_openamp to setup the trace buffer in the resource table.
+
+linker-script.ld:
+```
+SECTIONS
+{
+  .dram ():
+  {
+    /* Trace buffer */
+    __ethosu_core_trace_buffer_start__ = .;
+    *(ethosu_core_trace_buffer)
+    __ethosu_core_trace_buffer_size__ = ABSOLUTE(. - __ethosu_core_trace_buffer_start__);
+  } > DRAM_REGION
+```
+
+scatter-file.scatter:
+```
+LOAD_REGION_DRAM DRAM_ADDRESS DRAM_SIZE
+{
+    /* Trace buffer */
+    trace_buffer (DRAM_ADDRESS + 0x20000) FIXED
+    {
+        * (ethosu_core_trace_buffer)
+    }
+}
+```
+
+3. Allocate the trace buffer and place it in the section defined above using the `section` attribute. Finally, implement the `fputc` function in the retarget file so that writes to stderr and stdout are redirected to the trace buffer. Example:
+
+retarget.c:
+```
+#define TRACE_BUFFER_SIZE 0xXXXX
+__attribute__((section("ethosu_core_trace_buffer"))) char trace_buffer[TRACE_BUFFER_SIZE] = {0};
+int fputc(int ch, FILE *f) {
+    (void)f;
+    uint8_t c = (uint8_t)ch;
+
+    static uint32_t write = 0;
+    trace_buffer[write % TRACE_BUFFER_SIZE] = c;
+    write++;
+
+    return c;
+}
+```
+