uart_commands.(ch): small refinements, added "erase" command for EEPROM

src/uart/uart_commands.c

@@ -3,7 +3,9 @@
 #include <ctype.h>
 #include <stdbool.h>
 #include <setjmp.h>
+#include <avr/interrupt.h>
 #include <avr/pgmspace.h>
+#include <avr/eeprom.h>
 #include "../config.h"
 #include "../borg_hw/borg_hw.h"
 #ifdef JOYSTICK_SUPPORT
@@ -14,27 +16,27 @@
 #include "uart.h"
 #include "uart_commands.h"
 
-#define UART_SCROLL_BUFFER_SIZE (SCROLLTEXT_BUFFER_SIZE + 8)
+
-char g_rx_buffer[UART_SCROLL_BUFFER_SIZE];
+#define UART_BUFFER_SIZE (SCROLLTEXT_BUFFER_SIZE + 8)
+char g_rx_buffer[UART_BUFFER_SIZE];
 uint8_t g_rx_index;
 
 extern jmp_buf newmode_jmpbuf;
 volatile unsigned char mode;
 
-void uartcmd_clear_buffer(void) {
+#if !(defined(eeprom_update_block) && \
-	char *p = &g_rx_buffer[0];
+	((E2PAGESIZE == 2) || (E2PAGESIZE == 4) || (E2PAGESIZE == 8)))
-	for (uint8_t i = UART_SCROLL_BUFFER_SIZE; i--;) {
+char const UART_STR_NOTIMPL[] PROGMEM = "\r\nnot implemented";
-		*p++ = 0;
+#endif
-	}
-	g_rx_index = 0;
-}
 
 char const UART_STR_PROMPT[]  PROGMEM = "\r\n> ";
 char const UART_STR_ERROR[]   PROGMEM = "\r\ntransmission error";
 char const UART_STR_UNKNOWN[] PROGMEM = "\r\nunknown command";
 char const UART_STR_TOOLONG[] PROGMEM = "\r\ncommand to long";
-char const UART_STR_HELP[]    PROGMEM = "\r\nhelp msg next prev reset scroll";
+char const UART_STR_HELP[]    PROGMEM = "\r\nallowed commands: "
+                                        "erase help msg next prev reset scroll";
 
+char const UART_CMD_ERASE[]   PROGMEM = "erase";
 char const UART_CMD_HELP[]    PROGMEM = "help";
 char const UART_CMD_MSG[]     PROGMEM = "msg ";
 char const UART_CMD_NEXT[]    PROGMEM = "next";
@@ -42,8 +44,122 @@ char const UART_CMD_PREV[]    PROGMEM = "prev";
 char const UART_CMD_RESET[]   PROGMEM = "reset";
 char const UART_CMD_SCROLL[]  PROGMEM = "scroll ";
 
-bool uartcmd_read_until_enter(void) {
+
-	while (g_rx_index < (UART_SCROLL_BUFFER_SIZE - 1)) {
+bool g_uartcmd_permit_processing = 1;
+
+
+/**
+ * Checks if command processing is allowed.
+ */
+static bool uartcmd_processing_allowed(void) {
+	bool result;
+	cli();
+	result = g_uartcmd_permit_processing;
+	sei();
+	return result;
+}
+
+
+/**
+ * Clears the command string buffer.
+ */
+static void uartcmd_clear_buffer(void) {
+	char *p = &g_rx_buffer[0];
+	for (uint8_t i = UART_BUFFER_SIZE; i--;) {
+		*p++ = 0;
+	}
+	g_rx_index = 0;
+}
+
+
+/**
+ * Erases the complete EEPROM to reset counters and high score tables.
+ */
+static void uartcmd_erase_eeprom(void) {
+#if defined(eeprom_update_block) && \
+	((E2PAGESIZE == 2) || (E2PAGESIZE == 4) || (E2PAGESIZE == 8))
+	uint8_t const eeclear[] =
+#	if E2PAGESIZE == 8
+		{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+#	elif E2PAGESIZE == 4
+		{0xFF, 0xFF, 0xFF, 0xFF};
+#	elif E2PAGESIZE == 2
+		{0xFF, 0xFF};
+#	endif
+	for (void *ee = 0; ee < (void *)E2END; ee += E2PAGESIZE) {
+		eeprom_update_block(eeclear, ee, E2PAGESIZE);
+	}
+#else
+	uart_puts_p(UART_STR_NOTIMPL);
+#endif
+}
+
+
+/**
+ * Displays a simple message without the need to prefix a scrolltext command.
+ */
+static void uartcmd_simple_message(void) {
+	g_rx_buffer[1] = '<';
+	g_rx_buffer[2] = '/';
+	g_rx_buffer[3] = '#';
+	// text must not be longer than the scroll text buffer
+	g_rx_buffer[1 + SCROLLTEXT_BUFFER_SIZE - 1] = 0;
+	scrolltext(&g_rx_buffer[1]);
+}
+
+
+/**
+ * Displays a message which may use the complete range of scrolltext commands.
+ */
+static void uartcmd_scroll_message(void) {
+	// text must not be longer than the scroll text buffer
+	g_rx_buffer[7 + SCROLLTEXT_BUFFER_SIZE - 1] = 0;
+	scrolltext(&g_rx_buffer[7]);
+}
+
+
+/**
+ * As long there's no game active, jump to the next animation.
+ */
+static void uartcmd_next_anim(void) {
+	uart_puts_p(UART_STR_PROMPT);
+	uartcmd_clear_buffer();
+#ifdef JOYSTICK_SUPPORT
+	if (waitForFire)
+#endif
+		longjmp(newmode_jmpbuf, mode);
+}
+
+
+/**
+ * As long there's no game active, jump to the previous animation.
+ */
+static void uartcmd_prev_anim(void) {
+	uart_puts_p(UART_STR_PROMPT);
+	uartcmd_clear_buffer();
+	if (mode > 1) {
+#ifdef JOYSTICK_SUPPORT
+		if (waitForFire)
+#endif
+			longjmp(newmode_jmpbuf, mode - 2);
+	}
+}
+
+
+/**
+ * Perform a MCU reset by triggering the watchdog.
+ */
+static void uartcmd_reset_borg() {
+	timer0_off();
+}
+
+
+/**
+ * Appends new characters the buffer until a line break is entered.
+ * @return true if a line break was entered, false otherwise.
+ */
+static bool uartcmd_read_until_enter(void) {
+	while (g_rx_index < (UART_BUFFER_SIZE - 1)) {
 		int uart_result = uart_getc();
 
 		switch (uart_result & 0xFF00u) {
@@ -73,7 +189,7 @@ bool uartcmd_read_until_enter(void) {
 		}
 	}
 
-	if (g_rx_index >= (UART_SCROLL_BUFFER_SIZE - 1)) {
+	if (g_rx_index >= (UART_BUFFER_SIZE - 1)) {
 		uartcmd_clear_buffer();
 		uart_puts_p(UART_STR_TOOLONG);
 		uart_puts_p(UART_STR_PROMPT);
@@ -81,40 +197,25 @@ bool uartcmd_read_until_enter(void) {
 	return false;
 }
 
+/**
+ * Checks for entered commands and dispatches them to the appropriate handler.
+ */
 void uartcmd_process(void) {
-	if (uartcmd_read_until_enter()) {
+	if (uartcmd_processing_allowed() && uartcmd_read_until_enter()) {
-		if (!strncmp_P(g_rx_buffer, UART_CMD_HELP, 4)) {
+		if (!strncmp_P(g_rx_buffer, UART_CMD_ERASE, 5)) {
+			uartcmd_erase_eeprom();
+		} else if (!strncmp_P(g_rx_buffer, UART_CMD_HELP, UART_BUFFER_SIZE)) {
 			uart_puts_p(UART_STR_HELP);
 		} else if (!strncmp_P(g_rx_buffer, UART_CMD_MSG, 4)) {
-			g_rx_buffer[1] = '<';
+			uartcmd_simple_message();
-			g_rx_buffer[2] = '/';
+		} else if (!strncmp_P(g_rx_buffer, UART_CMD_NEXT, UART_BUFFER_SIZE)) {
-			g_rx_buffer[3] = '#';
+			uartcmd_next_anim();
-			// text must not be longer than the scroll text buffer
+		} else if (!strncmp_P(g_rx_buffer, UART_CMD_PREV, UART_BUFFER_SIZE)) {
-			g_rx_buffer[1 + SCROLLTEXT_BUFFER_SIZE - 1] = 0;
+			uartcmd_prev_anim();
-			scrolltext(&g_rx_buffer[1]);
+		} else if (!strncmp_P(g_rx_buffer, UART_CMD_RESET, UART_BUFFER_SIZE)) {
-		} else if (!strncmp_P(g_rx_buffer, UART_CMD_NEXT, 4)) {
+			uartcmd_reset_borg();
-			uart_puts_p(UART_STR_PROMPT);
-			uartcmd_clear_buffer();
-#ifdef JOYSTICK_SUPPORT
-			if (waitForFire)
-#endif
-				longjmp(newmode_jmpbuf, mode);
-		} else if (!strncmp_P(g_rx_buffer, UART_CMD_PREV, 4)) {
-			uart_puts_p(UART_STR_PROMPT);
-			uartcmd_clear_buffer();
-			if (mode > 1) {
-#ifdef JOYSTICK_SUPPORT
-				if (waitForFire)
-#endif
-					longjmp(newmode_jmpbuf, mode - 2);
-			}
-		} else if (!strncmp_P(g_rx_buffer, UART_CMD_RESET,
-				UART_SCROLL_BUFFER_SIZE)) {
-			timer0_off();
 		} else if (!strncmp_P(g_rx_buffer, UART_CMD_SCROLL, 7)) {
-			// text must not be longer than the scroll text buffer
+			uartcmd_scroll_message();
-			g_rx_buffer[7 + SCROLLTEXT_BUFFER_SIZE - 1] = 0;
-			scrolltext(&g_rx_buffer[7]);
 		} else {
 			uart_puts_p(UART_STR_UNKNOWN);
 		}

src/uart/uart_commands.h

@@ -8,6 +8,31 @@
 #ifndef UART_COMMANDS_H_
 #define UART_COMMANDS_H_
 
+#include <stdbool.h>
+#include <avr/interrupt.h>
+
+extern bool g_uartcmd_permit_processing;
+
+/**
+ * Enables UART command processing.
+ */
+inline static void uartcmd_permit(void) {
+	cli();
+	g_uartcmd_permit_processing = true;
+	sei();
+}
+
+
+/**
+ * Disables UART command processing.
+ */
+inline static void uartcmd_forbid(void) {
+	cli();
+	g_uartcmd_permit_processing = false;
+	sei();
+}
+
+
 void uartcmd_process(void);
 
 #endif /* UART_COMMANDS_H_ */