Add simple mongoose/esp32 example (w/out mOS)

PUBLISHED_FROM=0e407a2fb328107540d753123fe027f43860d0ef

examples/ESP32_IDF/Makefile

+SDK_VER=$(shell cat sdk.version)
+
+.PHONY: all
+
+MG_PATH = $(realpath $(PWD)/../../)
+
+all:
+	docker run --rm -it -v $(MG_PATH):/esp32_idf \
+                   $(SDK_VER) \
+                   bash -c "cd esp32_idf/examples/ESP32_IDF && \
+                   make -f Makefile.build defconfig && make -f Makefile.build"
+
+clean:
+	docker run --rm -it -v $(MG_PATH):/esp32_idf \
+                   $(SDK_VER) \
+                   bash -c "rm -rf esp32_idf/examples/ESP32_IDF/build"

examples/ESP32_IDF/Makefile.build

+#
+# This is a project Makefile. It is assumed the directory this Makefile resides in is a
+# project subdirectory.
+#
+
+PROJECT_NAME := esp32_idf
+
+include $(IDF_PATH)/make/project.mk
+

examples/ESP32_IDF/README.md

+This is a Mongoose "Hello, world" that can be compiled under Espressif IoT Development Framework for ESP32
+
+It connects to WiFi network and serves a "hello world" page.
+
+Most of the the boilerplate comes from [project_template](https://github.com/espressif/esp-idf-template) with minimal changes.
+
+For building the example, you need to have [Docker](https://www.docker.com/products/docker) and use our pre-built SDK container.
+To build just run in the example directory
+```
+$ make
+```
+
+Note: before building, change `WIFI_SSID` and `WIFI_PASS` macros in main/main.c file
+
+Once built, use [esptool](https://github.com/espressif/esptool) for flashing
+```
+$ python esptool.py --chip esp32 --port /dev/ttyUSB0 --baud 115200 --before default_reset --after hard_reset write_flash -u --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 build/bootloader/bootloader.bin 0x10000 build/esp32_idf.bin 0x8000 build/partitions_singleapp.bin
+```

examples/ESP32_IDF/main/component.mk

+#
+# Main component makefile.
+#
+# This Makefile can be left empty. By default, it will take the sources in the
+# src/ directory, compile them and link them into lib(subdirectory_name).a
+# in the build directory. This behaviour is entirely configurable,
+# please read the ESP-IDF documents if you need to do this.
+#
+
+COMPONENT_OBJS = main.o mongoose.o
+
+mongoose.o: ../../../../mongoose.c
+	$(summary) "CC $@"
+	$(CC) $(CFLAGS) $(CPPFLAGS) \
+	  $(addprefix -I ,$(COMPONENT_INCLUDES)) \
+	  $(addprefix -I ,$(COMPONENT_EXTRA_INCLUDES)) \
+	  -c $< -o $@

examples/ESP32_IDF/main/main.c

+#include <string.h>
+
+#include "freertos/FreeRTOS.h"
+
+#include "esp_event.h"
+#include "esp_event_loop.h"
+#include "esp_system.h"
+#include "esp_wifi.h"
+#include "nvs_flash.h"
+
+#include "./../../../mongoose.h"
+
+#define WIFI_SSID "ssid"
+#define WIFI_PASS "pass"
+
+#define MG_LISTEN_ADDR "80"
+
+static esp_err_t event_handler(void *ctx, system_event_t *event) {
+  (void) ctx;
+  (void) event;
+  return ESP_OK;
+}
+
+static void mg_ev_handler(struct mg_connection *nc, int ev, void *p) {
+  static const char *reply_fmt =
+      "HTTP/1.0 200 OK\r\n"
+      "Connection: close\r\n"
+      "Content-Type: text/plain\r\n"
+      "\r\n"
+      "Hello %s\n";
+
+  switch (ev) {
+    case MG_EV_ACCEPT: {
+      char addr[32];
+      mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr),
+                          MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+      printf("Connection %p from %s\n", nc, addr);
+      break;
+    }
+    case MG_EV_HTTP_REQUEST: {
+      char addr[32];
+      struct http_message *hm = (struct http_message *) p;
+      mg_sock_addr_to_str(&nc->sa, addr, sizeof(addr),
+                          MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
+      printf("HTTP request from %s: %.*s %.*s\n", addr, (int) hm->method.len,
+             hm->method.p, (int) hm->uri.len, hm->uri.p);
+      mg_printf(nc, reply_fmt, addr);
+      nc->flags |= MG_F_SEND_AND_CLOSE;
+      break;
+    }
+    case MG_EV_CLOSE: {
+      printf("Connection %p closed\n", nc);
+      break;
+    }
+  }
+}
+
+void app_main(void) {
+  nvs_flash_init();
+  tcpip_adapter_init();
+  ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
+
+  /* Initializing WiFi */
+  wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+  ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+  ESP_ERROR_CHECK(esp_wifi_set_storage(WIFI_STORAGE_RAM));
+  ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+  wifi_config_t sta_config = {
+      .sta = {.ssid = WIFI_SSID, .password = WIFI_PASS, .bssid_set = false}};
+  ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &sta_config));
+  ESP_ERROR_CHECK(esp_wifi_start());
+  ESP_ERROR_CHECK(esp_wifi_connect());
+
+  /* Starting Mongoose */
+  struct mg_mgr mgr;
+  struct mg_connection *nc;
+
+  printf("Starting web-server on port %s\n", MG_LISTEN_ADDR);
+
+  mg_mgr_init(&mgr, NULL);
+
+  nc = mg_bind(&mgr, MG_LISTEN_ADDR, mg_ev_handler);
+  if (nc == NULL) {
+    printf("Error setting up listener!\n");
+    return;
+  }
+  mg_set_protocol_http_websocket(nc);
+
+  /* Processing events */
+  while (1) {
+    mg_mgr_poll(&mgr, 1000);
+  }
+}

examples/ESP32_IDF/sdk.version

+docker.cesanta.com/esp32-build:1.0-r13

examples/Makefile

@@ -3,7 +3,7 @@
 
 # `wildcard ./*/` works in both linux and linux/wine, while `wildcard */` enumerates nothing under wine
 SUBDIRS = $(sort $(dir $(wildcard ./*/)))
-SUBDIRS:=$(filter-out ./ ./CC3200/ ./ESP8266_RTOS/ ./mbed/ ./MSP432/ ./nRF51/ ./nRF52/ ./NXP_K64/ ./NXP_LPC4088/ ./PIC32/ ./STM32F4_CC3100/ ./TM4C129/ ./WinCE/, $(SUBDIRS))
+SUBDIRS:=$(filter-out ./ ./CC3200/ ./ESP32_IDF/ ./ESP8266_RTOS/ ./mbed/ ./MSP432/ ./nRF51/ ./nRF52/ ./NXP_K64/ ./NXP_LPC4088/ ./PIC32/ ./STM32F4_CC3100/ ./TM4C129/ ./WinCE/, $(SUBDIRS))
 
 ifeq ($(OS), Windows_NT)
   SUBDIRS:=$(filter-out ./netcat/ ./raspberry_pi_mjpeg_led/ ./captive_dns_server/, $(SUBDIRS))