Add logging support for core_debug()

Author: kbumsik

cores/arduino/Print.cpp

@@ -197,16 +197,45 @@ size_t Print::println(const Printable &x)
 }
 
 extern "C" {
+#if defined (__LOG_TRACE_IO_)
+  /**
+   * By writing OpenAMP trace (log) buffer here, the Linux host can access
+   * to the content by the following command:
+   *   $ cat /sys/kernel/debug/remoteproc/remoteproc0/trace0
+   * Ceveats - When the buffer overflows (2kb), the buffer is cleaned by
+   * a null character. 2kb will be enough for core_debug() logging.
+   */
+#include "virtio_config.h"
+
+  char system_log_buf[SYSTEM_TRACE_BUF_SZ];
+
+  void log_buff(uint8_t *data, uint32_t size)
+  {
+    static int offset = 0;
+
+    for (uint32_t i = 0; i < size; i++) {
+      system_log_buf[offset++] = *(data + i);
+      if ((offset + 1) >= SYSTEM_TRACE_BUF_SZ) {
+        offset = 0;
+      }
+    }
+    system_log_buf[offset] = '\0';
+  }
+#endif
+
   __attribute__((weak))
   int _write(int file, char *ptr, int len)
   {
     switch (file) {
       case STDOUT_FILENO:
       case STDERR_FILENO:
-#if defined(HAL_UART_MODULE_ENABLED) && !defined(HAL_UART_MODULE_ONLY)
         /* Used for core_debug() */
+#if defined (__LOG_TRACE_IO_)
+        log_buff((uint8_t *)ptr, (uint32_t)len);
+#elif defined(HAL_UART_MODULE_ENABLED) && !defined(HAL_UART_MODULE_ONLY)
         uart_debug_write((uint8_t *)ptr, (uint32_t)len);
 #endif
+        break;
       case STDIN_FILENO:
         break;
       default:

cores/arduino/VirtIOSerial.h

@@ -27,7 +27,6 @@
 #if defined (VIRTIOCON)
 #include "Stream.h"
 #include "openamp.h"
-#include "openamp_log.h"
 #include "wiring.h"
 #include "virtio_buffer.h"
 

cores/arduino/stm32/OpenAMP/openamp_conf.h

@@ -30,10 +30,6 @@ extern "C" {
 #endif
 
 /* Includes ------------------------------------------------------------------*/
-#if defined (__LOG_TRACE_IO_) || defined(__LOG_UART_IO_)
-#include "openamp_log.h"
-#endif
-
 /* ########################## Mailbox Interface Selection ############################## */
 /**
   * @brief This is the list of Mailbox interface  to be used in the OpenAMP MW
@@ -138,29 +134,6 @@ extern int __OPENAMP_region_end__[];    /* defined by linker script */
 #define VRING0_ID               0         /* VRING0 ID (master to remote) fixed to 0 for linux compatibility*/
 #define VRING1_ID               1         /* VRING1 ID (remote to master) fixed to 1 for linux compatibility  */
 
-/**
-  * @}
-  */
-
-/** @defgroup OPENAMP_CONF_Exported_Macros OPENAMP_CONF_Exported_Macros
-  * @brief Aliases.
-  * @{
-  */
-
-/* DEBUG macros */
-
-#if defined (__LOG_TRACE_IO_) || defined(__LOG_UART_IO_)
-#define OPENAMP_log_dbg               log_dbg
-#define OPENAMP_log_info              log_info
-#define OPENAMP_log_warn              log_warn
-#define OPENAMP_log_err               log_err
-#else
-#define OPENAMP_log_dbg(...)
-#define OPENAMP_log_info(...)
-#define OPENAMP_log_warn(...)
-#define OPENAMP_log_err(...)
-#endif
-
 /**
   * @}
   */

cores/arduino/stm32/OpenAMP/openamp_log.c

@@ -1,13 +1,21 @@
 #ifndef __VIRTIO_CONFIG_H
 #define __VIRTIO_CONFIG_H
 
+// Size of buffer of each vring buffers
 #ifdef RPMSG_BUFFER_SIZE
-#error "RPMSG_BUFFER_SIZE is already defined"
+#error "RPMSG_BUFFER_SIZE should be aligned with the kernel definition."
+#error "Reference: https://elixir.bootlin.com/linux/v5.5.2/source/drivers/rpmsg/virtio_rpmsg_bus.c#L137"
 #else
 #define RPMSG_BUFFER_SIZE (512)
 #endif
 
 // Size of the vqueue message in the buffer
 #define RPMSG_VRING_HEADER_SIZE 16
 
+#if defined (__LOG_TRACE_IO_)
+// OpenAMP trace (log) buffer configuration. See rsc_table.c and Print.cpp
+#define SYSTEM_TRACE_BUF_SZ 2048
+extern char system_log_buf[SYSTEM_TRACE_BUF_SZ]; /*!< buffer for debug traces */
+#endif
+
 #endif // __VIRTIO_CONFIG_H