Add host target platform (#4783)

Co-authored-by: Otto winter <otto@otto-winter.com>

esphome/components/host/core.cpp

@@ -0,0 +1,77 @@
+#ifdef USE_HOST
+
+#include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
+#include "preferences.h"
+
+#include <sched.h>
+#include <time.h>
+#include <cmath>
+#include <cstdlib>
+
+namespace esphome {
+
+void IRAM_ATTR HOT yield() { ::sched_yield(); }
+uint32_t IRAM_ATTR HOT millis() {
+  struct timespec spec;
+  clock_gettime(CLOCK_MONOTONIC, &spec);
+  time_t seconds = spec.tv_sec;
+  uint32_t ms = round(spec.tv_nsec / 1e6);
+  return ((uint32_t) seconds) * 1000U + ms;
+}
+void IRAM_ATTR HOT delay(uint32_t ms) {
+  struct timespec ts;
+  ts.tv_sec = ms / 1000;
+  ts.tv_nsec = (ms % 1000) * 1000000;
+  int res;
+  do {
+    res = nanosleep(&ts, &ts);
+  } while (res != 0 && errno == EINTR);
+}
+uint32_t IRAM_ATTR HOT micros() {
+  struct timespec spec;
+  clock_gettime(CLOCK_MONOTONIC, &spec);
+  time_t seconds = spec.tv_sec;
+  uint32_t us = round(spec.tv_nsec / 1e3);
+  return ((uint32_t) seconds) * 1000000U + us;
+}
+void IRAM_ATTR HOT delayMicroseconds(uint32_t us) {
+  struct timespec ts;
+  ts.tv_sec = us / 1000000U;
+  ts.tv_nsec = (us % 1000000U) * 1000U;
+  int res;
+  do {
+    res = nanosleep(&ts, &ts);
+  } while (res != 0 && errno == EINTR);
+}
+void arch_restart() { exit(0); }
+void arch_init() {
+  // pass
+}
+void IRAM_ATTR HOT arch_feed_wdt() {
+  // pass
+}
+
+uint8_t progmem_read_byte(const uint8_t *addr) { return *addr; }
+uint32_t arch_get_cpu_cycle_count() {
+  struct timespec spec;
+  clock_gettime(CLOCK_MONOTONIC, &spec);
+  time_t seconds = spec.tv_sec;
+  uint32_t us = spec.tv_nsec;
+  return ((uint32_t) seconds) * 1000000000U + us;
+}
+uint32_t arch_get_cpu_freq_hz() { return 1000000000U; }
+
+}  // namespace esphome
+
+void setup();
+void loop();
+int main() {
+  esphome::host::setup_preferences();
+  setup();
+  while (true) {
+    loop();
+  }
+}
+
+#endif  // USE_HOST