emulation on host: Add full UART driver emulation. (esp8266#5785)

* emulation on host: Add full UART driver emulation.

  This PR replaces the high level Serial mock with a more complete
  UART driver. This way the HardwareSerial works without any
  modifications. Additionally the driver supports UART0 and UART1
  at the same time (UART0 is directed to stdout and UART1 writes
  to stderr). RX is implemented by switching the terminal into raw
  non-blocking mode and injecting each key-press directly into the
  FIFO of UART0. A new command line switch -c was added to ignore
  CTRL-C and send it via serial as well. The decumentation was
  updated accordingly.

  Reading and setting of GPIOs does only write to stderr, when compiled
  with D=1. But this is subject to be replaced with a proper GPIO emu
  anyway. Reading from GPIO0 now returns 1 instead of 0 because this is
  most likely a low active input.

* Fixed unused variable.

* Remove unused functions, as long as there are no debug macros using them.

* Move user_interface.cc from MOCK_CPP_FILES_EMU to MOCK_CPP_FILES.

* Move optimistic_yield() from user_interface.cpp to Arduino.cpp

* Remove atexit() weak declaration (fixes segfault when calling atexit).

* Improve resetting of terminal after program exit, convert \r to \r\n.

* Show error, when STDOUT is not a TTY, minor code cleanung.

tests/host/Makefile

@@ -65,6 +65,7 @@ CORE_CPP_FILES := $(addprefix $(CORE_PATH)/,\
 	libb64/cencode.cpp \
 	libb64/cdecode.cpp \
 	Schedule.cpp \
+	HardwareSerial.cpp \
 )
 
 CORE_C_FILES := $(addprefix $(CORE_PATH)/,\
@@ -74,7 +75,7 @@ MOCK_CPP_FILES_COMMON := $(addprefix common/,\
 	Arduino.cpp \
 	spiffs_mock.cpp \
 	WMath.cpp \
-	MockSerial.cpp \
+	MockUART.cpp \
 	MockTools.cpp \
 	MocklwIP.cpp \
 )
@@ -95,7 +96,6 @@ MOCK_C_FILES := $(addprefix common/,\
 	noniso.c \
 )
 
-
 INC_PATHS += $(addprefix -I, \
 	. \
 	common \
@@ -231,7 +231,7 @@ ARDUINO_LIBS := \
 		WiFiServerSecureBearSSL.cpp \
 		BearSSLHelpers.cpp \
 		CertStoreBearSSL.cpp \
-	) \
+	)
 
 OPT_ARDUINO_LIBS ?= $(addprefix ../../libraries/,\
 	$(addprefix ESP8266WebServer/src/,\
@@ -251,7 +251,7 @@ OPT_ARDUINO_LIBS ?= $(addprefix ../../libraries/,\
 	DNSServer/src/DNSServer.cpp \
 	ESP8266AVRISP/src/ESP8266AVRISP.cpp \
 	ESP8266HTTPClient/src/ESP8266HTTPClient.cpp \
-) \
+)
 
 MOCK_ARDUINO_LIBS := $(addprefix common/,\
 	ClientContextSocket.cpp \
@@ -263,7 +263,7 @@ MOCK_ARDUINO_LIBS := $(addprefix common/,\
 	MockEsp.cpp \
 	MockEEPROM.cpp \
 	MockSPI.cpp \
-) \
+)
 
 CPP_SOURCES_CORE_EMU = \
 	$(MOCK_CPP_FILES_EMU) \

tests/host/README.txt

@@ -19,6 +19,13 @@ WiFiClient+WiFiServer/ClientContext and WifiUdp/UdpContext using socket
 posix API.  Further work will optionally propose native lwIP library
 instead.
 
+Serial UART0 and UART1 are emulated via stdin/stdout/stderr.  Therefor
+stdin is connected to UART0(RX) and stdout is connected to UART0(TX).
+UART1(TX) writes to stderr.  Reading from stdin happens in non-blocking
+raw mode, that means each character is directly injected into the UART
+FIFO without any buffering in the console.  The command line switch -c
+can be used to stop the emulation from intersepting CTRL-C (SIGINT).
+
 How to compile and run a sketch
 -------------------------------
 
@@ -73,7 +80,10 @@ Options are available:
 	-h
 	-i eth0		bind servers to this interface (WIP)
 	-l		bind Multicast to the above interface (WIP)
-	-f              no throttle (possibly 100%CPU)
+	-c		ignore CTRL-C (send it over serial device)
+	-f		no throttle (possibly 100%CPU)
+	-S		spiffs size in KBytes (default: 1024)
+			(negative value will force mismatched size)
 
 TODO
 ----

tests/host/common/Arduino.cpp

@@ -37,6 +37,11 @@ extern "C" void yield()
 {
 }
 
+extern "C" void optimistic_yield (uint32_t interval_us)
+{
+    usleep(interval_us);
+}
+
 extern "C" void esp_yield()
 {
 }

tests/host/common/Arduino.h

@@ -191,8 +191,6 @@ extern "C" {
     void init(void);
     void initVariant(void);
 
-    int atexit(void (*func)()) __attribute__((weak));
-
     void pinMode(uint8_t pin, uint8_t mode);
     void digitalWrite(uint8_t pin, uint8_t val);
     int digitalRead(uint8_t pin);

tests/host/common/ArduinoMain.cpp

@@ -33,12 +33,58 @@
 #include <user_interface.h> // wifi_get_ip_info()
 
 #include <signal.h>
-#include <unistd.h> // usleep
+#include <unistd.h>
 #include <getopt.h>
+#include <termios.h>
+#include <stdarg.h>
+#include <stdio.h>
 
 bool user_exit = false;
 const char* host_interface = nullptr;
 size_t spiffs_kb = 1024;
+bool ignore_sigint = false;
+bool restore_tty = false;
+
+#define STDIN STDIN_FILENO
+
+static struct termios initial_settings;
+
+static int mock_start_uart(void)
+{
+	struct termios settings;
+
+	if (!isatty(STDIN)) return 0;
+	if (tcgetattr(STDIN, &initial_settings) < 0) return -1;
+	settings = initial_settings;
+	settings.c_lflag &= ~(ignore_sigint ? ISIG : 0);
+	settings.c_lflag &= ~(ECHO	| ICANON);
+	settings.c_iflag &= ~(ICRNL | INLCR | ISTRIP | IXON);
+	settings.c_oflag |=	(ONLCR);
+	settings.c_cc[VMIN]	= 0;
+	settings.c_cc[VTIME] = 0;
+	if (tcsetattr(STDIN, TCSANOW, &settings) < 0) return -2;
+	tty_restore = true;
+	return 0;
+}
+
+static int mock_stop_uart(void)
+{
+	if (!restore_tty) return 0;
+	if (!isatty(STDIN)) {
+		perror("isatty(STDIN)");
+		//system("stty sane"); <- same error message "Inappropriate ioctl for device"
+		return 0;
+	}
+	if (tcsetattr(STDIN, TCSANOW, &initial_settings) < 0) return -1;
+	printf("\e[?25h"); // show cursor
+	return (0);
+}
+
+static uint8_t mock_read_uart(void)
+{
+	uint8_t ch = 0;
+	return (read(STDIN, &ch, 1) == 1) ? ch : 0;
+}
 
 void help (const char* argv0, int exitcode)
 {
@@ -48,9 +94,10 @@ void help (const char* argv0, int exitcode)
 		"	-h\n"
 		"	-i <interface> - use this interface for IP address\n"
 		"	-l             - bind tcp/udp servers to interface only (not 0.0.0.0)\n"
+		"	-c             - ignore CTRL-C (send it via Serial)\n"
 		"	-f             - no throttle (possibly 100%%CPU)\n"
 		"	-S             - spiffs size in KBytes (default: %zd)\n"
-		"	                 (negative value will force mismatched size)\n"
+		"                  (negative value will force mismatched size)\n"
 		, argv0, spiffs_kb);
 	exit(exitcode);
 }
@@ -60,13 +107,15 @@ static struct option options[] =
 	{ "help",		no_argument,		NULL, 'h' },
 	{ "fast",		no_argument,		NULL, 'f' },
 	{ "local",		no_argument,		NULL, 'l' },
+	{ "sigint",		no_argument,		NULL, 'c' },
 	{ "interface",		required_argument,	NULL, 'i' },
 	{ "spiffskb",		required_argument,	NULL, 'S' },
 };
 
-void save ()
+void cleanup ()
 {
 	mock_stop_spiffs();
+	mock_stop_uart();
 }
 
 void control_c (int sig)
@@ -76,7 +125,7 @@ void control_c (int sig)
 	if (user_exit)
 	{
 		fprintf(stderr, MOCK "stuck, killing\n");
-		save();
+		cleanup();
 		exit(1);
 	}
 	user_exit = true;
@@ -90,7 +139,7 @@ int main (int argc, char* const argv [])
 
 	for (;;)
 	{
-		int n = getopt_long(argc, argv, "hlfi:S:", options, NULL);
+		int n = getopt_long(argc, argv, "hlcfi:S:", options, NULL);
 		if (n < 0)
 			break;
 		switch (n)
@@ -104,6 +153,9 @@ int main (int argc, char* const argv [])
 		case 'l':
 			global_ipv4_netfmt = NO_GLOBAL_BINDING;
 			break;
+		case 'c':
+			ignore_sigint = true;
+			break;
 		case 'f':
 			fast = true;
 			break;
@@ -128,16 +180,25 @@ int main (int argc, char* const argv [])
 	// setup global global_ipv4_netfmt
 	wifi_get_ip_info(0, nullptr);
 
+	// set stdin to non blocking mode
+	mock_start_uart();
+
+	// install exit handler in case Esp.restart() is called
+	atexit(cleanup);
+
 	setup();
 	while (!user_exit)
 	{
+		uint8_t data = mock_read_uart();
+
+		if (data)
+			uart_new_data(UART0, data);
 		if (!fast)
-			usleep(10000); // not 100% cpu
+			usleep(1000); // not 100% cpu, ~1000 loops per second
 		loop();
 		check_incoming_udp();
 	}
-
-	save();
+	cleanup();
 
 	return 0;
 }

tests/host/common/HostWiring.cpp

@@ -46,17 +46,23 @@ void pinMode (uint8_t pin, uint8_t mode)
 	case WAKEUP_PULLDOWN: m="WAKEUP_PULLDOWN"; break;
 	default: m="(special)";
 	}
+#ifdef DEBUG_ESP_CORE
 	fprintf(stderr, MOCK "gpio%d: mode='%s'\n", pin, m);
+#endif
 }
 
 void digitalWrite(uint8_t pin, uint8_t val)
 {
+#ifdef DEBUG_ESP_CORE
 	fprintf(stderr, MOCK "digitalWrite(pin=%d val=%d)\n", pin, val);
+#endif
 }
 
 void analogWrite(uint8_t pin, int val)
 {
+#ifdef DEBUG_ESP_CORE
 	fprintf(stderr, MOCK "analogWrite(pin=%d, val=%d\n", pin, val);
+#endif
 }
 
 int analogRead(uint8_t pin)
@@ -67,11 +73,17 @@ int analogRead(uint8_t pin)
 
 void analogWriteRange(uint32_t range)
 {
+#ifdef DEBUG_ESP_CORE
 	fprintf(stderr, MOCK "analogWriteRange(range=%d)\n", range);
+#endif
 }
 
 int digitalRead(uint8_t pin)
 {
+#ifdef DEBUG_ESP_CORE
 	fprintf(stderr, MOCK "digitalRead(%d)\n", pin);
-	return 0;
+#endif
+
+	// pin 0 is most likely a low active input
+	return pin ? 0 : 1;
 }