add RT-Thread support

src/arch.h

@@ -14,6 +14,7 @@
 #define MG_ARCH_RP2040 11      // Raspberry Pi RP2040
 #define MG_ARCH_ARMCC 12       // Keil MDK-Core with Configuration Wizard
 #define MG_ARCH_CMSIS_RTOS2 13 // CMSIS-RTOS API v2 (Keil RTX5, FreeRTOS)
+#define MG_ARCH_RTTHREAD 14    // RT-Thread RTOS
 
 #if !defined(MG_ARCH)
 #if defined(__unix__) || defined(__APPLE__)
@@ -35,6 +36,8 @@
 #define MG_ARCH MG_ARCH_RP2040
 #elif defined(__ARMCC_VERSION)
 #define MG_ARCH MG_ARCH_ARMCC
+#elif defined(__RTTHREAD__)
+#define MG_ARCH MG_ARCH_RTTHREAD
 #endif
 #endif  // !defined(MG_ARCH)
 

src/arch_rtthread.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#if MG_ARCH == MG_ARCH_RTTHREAD
+
+#include <rtthread.h>
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/select.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <time.h>
+
+#ifndef MG_IO_SIZE
+#define MG_IO_SIZE 1460
+#endif
+
+#endif // MG_ARCH == MG_ARCH_RTTHREAD

src/util.c

@@ -113,6 +113,8 @@ uint64_t mg_millis(void) {
   return (uint64_t)rt_time_get();
 #elif MG_ARCH == MG_ARCH_CMSIS_RTOS2
   return (uint64_t)((osKernelGetTickCount() * 1000) / osKernelGetTickFreq());
+#elif MG_ARCH == MG_ARCH_RTTHREAD
+  return (uint64_t) ((rt_tick_get() * 1000) / RT_TICK_PER_SECOND);
 #elif MG_ARCH == MG_ARCH_UNIX && defined(__APPLE__)
   // Apple CLOCK_MONOTONIC_RAW is equivalent to CLOCK_BOOTTIME on linux
   // Apple CLOCK_UPTIME_RAW is equivalent to CLOCK_MONOTONIC_RAW on linux