From bc6f94e353e0d0c0536fa8847f3b8f4734f56007 Mon Sep 17 00:00:00 2001
From: Jessica Creighton <jcreigh@femtobit.org>
Date: Wed, 3 Apr 2019 16:44:48 -0400
Subject: [PATCH] Finish initial ANSI Escape Sequence support - basic CSI
 sequences (cursor moving, line erasing) work

---
 arch/i386/tty.c      | 626 +++++++++++++++++++++++--------------------
 include/kernel/tty.h |  51 ++--
 2 files changed, 365 insertions(+), 312 deletions(-)

diff --git a/arch/i386/tty.c b/arch/i386/tty.c
index c37516d..94b9940 100755
--- a/arch/i386/tty.c
+++ b/arch/i386/tty.c
@@ -1,294 +1,332 @@
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-#include <kernel/tty.h>
-#include <kernel/utils.h>
-
-static const size_t TERM_WIDTH=80;
-static const size_t TERM_HEIGHT=25;
-
-static size_t terminal_row;
-static size_t terminal_column;
-
-static uint8_t current_color;
-static uint16_t* term_buffer;
-static uint16_t* const vga_buffer = (uint16_t*) 0xB8000;
-
-void screen_initialize(void) {
-	
-	terminal_row = 0;
-	terminal_column = 0;
-	current_color = vga_color_set(LIGHT_GREY, BLACK);
-	term_buffer = vga_buffer;
-	
-	for (size_t y = 0; y < TERM_HEIGHT; y++) {
-		for(size_t x = 0; x < TERM_WIDTH; x++) {
-			const size_t offset = y * TERM_WIDTH + x;
-			term_buffer[offset] = vga_entry(' ', current_color);
-		}
-	}
-}
-
-void term_setcolor(enum vga_colors color) {
-	current_color = color;
-}
-
-void term_putentryat (char c, uint8_t color, size_t x, size_t y) {
-	const size_t offset = y * TERM_WIDTH + x;
-	term_buffer[offset] = vga_entry(c, color);
-}
-
-void term_putchar(char c) {
-	unsigned char uc = c;
-	
-	//Handle escaped characters, such as newline, and crtn.
-	switch (uc) {
-		case '\n':
-			terminal_column = 0;
-			terminal_row += 1;
-			break;
-		default:
-			term_putentryat(uc, current_color, terminal_column, terminal_row);
-			break;
-	}
-	
-	if(++terminal_column == TERM_WIDTH) 
-	{
-		terminal_column = 0;
-		if(++terminal_row == TERM_HEIGHT){
-			term_scroll(false);
-			terminal_row = 0;
-		}
-	}
-}
-
-void term_write(const char* data, size_t size) {
-	for(size_t i = 0; i < size; i++) {
-		//Begin handling ANSI escape codes.
-		if(data[i] == 0x1B) { //The current character is ESC - the start of ANSI codes.
-			term_writes("ANSI Code encountered: ");
-			
-			bool string_terminated = false; //Flag used in some of the escape codes
-			switch(data[i+1]) {
-				case 0x9b/*[*/: //CSI - Control Sequence Introducer (The most common one, hence it comes first)
-					char* controlSequence;
-					if(data[i+2] == NULL) {
-						controlSequence = '\0';
-					for(size_t j = 0; j < (strlen(data) - (i+2); j++) {
-						if(data[j] == ' ') 
-							break;
-						controlSequence += data[j];
-					}
-					handleControlSequence(controlSequence); //Send it off to our handler function to keep this part clean
-					break;
-					
-				//Single shifts are not handled, so just print them and exit
-				case 0x8e/*N*/: //SS2 - Single Shift Two
-					term_writes("Single Shift Two\n");
-					break;
-				case 0x8f/*O*/: //SS3 - Single Shift Three
-					term_writes("Single Shift Three\n");
-					break;
-				
-				//Control Strings
-				case 0x90/*P*/: //DCS - Device Control String
-					term_writes("Device Control String");
-					string_terminated = false;
-					break;
-				case 0x9c/*\*/: //ST - String Terminator 
-					term_writes("String Terminator\n");
-					string_terminated = true;
-					break;
-				case 0x9d/*]*/: //OSC - Operating System Command
-					term_writes("Operating System Command\n");
-					string_terminated = false;
-					break;
-				case 0x98/*X*/: //SOS - Start Of String
-					term_writes("Start of String");
-					string_terminated = false;
-					break;
-				case 0x9e/*^*/: //PM - Privacy Message
-					term_writes("Privacy Message\n");
-					break;
-				case 0x9f/*_*/: //APC - Application Program Command
-					term_writes("Application Program Command\n");
-					break;
-			}
-			
-		}
-		
-		term_putchar(data[i]);
-	}
-}
-
-void term_writes(const char* data) {
-	term_write(data, strlen(data));
-}
-
-void puts(const char* string) { 
-	term_write(string, strlen(string));
-	term_putchar('\n');
-}
-
-void handleControlSequence(const char* sequence) {
-	//Check for our failsafes
-	if(sequence) {
-		if(sequence != '\0') {
-			int n = 0; //Default of the flag used for a few items
-			
-			bool nPresent = false;
-			bool terminated = false;
-			for(size_t i = 0; i < strlen(sequence); i++) {
-				if(isDigit(sequence[i])) {
-						nPresent = true;
-						n = (n*10) + sequence[i];
-					} else if(n > 80) {
-						n = 80;
-						break;
-					}
-				}
-				
-				if(n == 0)
-					n = 1;
-				
-				switch(sequence[i]) {
-					case ';':
-						terminated = true;
-						int m = 0; 
-						for(size_t j = 0; j < strlen(sequence - i); j++) {
-							if(sequence[j] == 'H' ||sequence[j] == 'f') 
-								break;
-							
-							if(isDigit(sequence[j])) {
-									m = (m*10) + sequence[j];
-							} else if(j > 80) break;
-						}
-						
-						if(m == 0)
-							m = 1;
-						cursor_pos(n, m);
-						
-						break;
-					case 'A': //CUU - Cursor Up
-						//cursor_pos(x, y)
-						
-						cursor_pos(terminal_column, terminal_row + n);
-						break;
-					case 'B': //CUD - Cursor Down
-						cursor_pos(terminal_column, terminal_row - n);
-						break;
-					case 'C': //CUF - Cursor Forward
-						cursor_pos(terminal_column + n, terminal_row);
-						break;
-					case 'D': //CUB - Cursor Back
-						cursor_pos(terminal_column - n, terminal_row);
-						break;
-					case 'E': //CNL - Cursor Next Line
-						cursor_pos(0, terminal_row + n);
-						break;
-					case 'F': //CPL - Cursor Previous Line
-						cursor_pos(0, terminal_row - n);
-						break;
-					case 'G': //CHA - Cursor Horizontal Absolute
-						cursor_pos(n, terminal_row);
-					case 'J': //ED - Erase in Display
-						//current cursor pos = y * width + x
-						int pos = terminal_row * 80 + terminal_column;
-						if(!nPresent) {
-							for(pos < (25 * 80); pos++) {
-								vga_buffer[pos] = '\0';
-							}
-							n = 0;
-						} else if(nPresent && n == 1) {
-							for(pos > 0; pos--) {
-								vga_buffer[pos] = '\0';
-							}
-						} else if(n == 2 || n == 3) {
-							for(int i = 0; i < (25*80); i++) {
-								vga_buffer[0] = '\0';
-							}
-						} 
-						break;
-					case 'K': //EL - Erase in Line
-					
-						int pos = terminal_row * 80 + terminal_column;
-						if(!nPresent) { //From cursor to end of line
-							int endPos = (terminal_row + 1) * 80 - 1; //End of line = current row + 25 columns = current row + 1
-							for(pos < endPos; pos++) {
-								vga_buffer[pos] = '\0';
-							}
-						} else if(nPresent && n == 1) { //From cursor to start of line
-							int endPos = terminal_row * 80; //Start of line = end of previous line + 1 == current line
-							for(pos > endPos; pos--) {
-								vga_buffer[pos] = '\0';
-							}
-						} else if(nPresent && n == 2) { //Entire current line
-							pos = terminal_row * 80;
-							int endPos = (terminal_row + 1) * 80 - 1;
-							for(pos < endPos; pos++) {
-								vga_buffer[pos] = '\0';
-							}
-						}
-						break;
-					case 'S': //SU - Scroll Up
-						term_scroll(true);
-						break;
-					case 'T': //SD - Scroll Down
-						term_scroll(false);
-						break;
-				}
-			}
-		}
-	}
-	
-}
-
-bool isDigit(const char c) {
-	return c == '0' || c == '1' || c == '2' || c == '3' ||
-			c == '4' || c == '5' || c == '6' || c == '7' ||
-			c == '8' || c == '9';
-}
-
-void term_scroll(bool down) {
-
-	int current_pos;
-	if(down) {
-		current_pos = 25 * 80; //Start of the last line.
-	} else {
-		current_pos = 160; //Start of the second line.
-	}
-	
-	unsigned char* term_buffer = (unsigned char*) vga_buffer;
-	
-	if(down) { //To scroll down, move every character into the one below it, or "pull" every character down
-		while(current_pos > 80) {
-			term_buffer[current_pos + 160] = vga_buffer[current_pos];
-			term_buffer[current_pos + 159] = vga_buffer[current_pos - 1];
-			current_pos -= 2;
-	} else {
-		while (current_pos <= 4000) {
-			term_buffer[current_pos - 160 /*The character immediately below it*/] = vga_buffer[current_pos];      //Move each character up a line
-			term_buffer[current_pos - 159 /*The color of the character below*/] = vga_buffer[current_pos + 1];    //As well as its color
-			current_pos += 2; //Move to next char
-		}
-	}
-	
-	if(down) {
-		current_pos = 0; //Start of first line
-		for(current_pos < 80; current_pos++) {
-			term_buffer[current_pos] = '\0';
-			current_pos += 2;
-	} else {
-		; //Start of the last line
-		//Wipe out the bottom line
-		for(current_pos = 3840; current_pos <= 3920; i++) {
-			term_buffer[current_pos] = 0;
-			current_pos += 2;
-		}
-	}
-	
-	terminal_row = 24; //Start writing on the last line
-	terminal_column = 0;
-}
\ No newline at end of file
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "kernel/tty.h"
+#include "kernel/utils.h"
+
+static const size_t TERM_WIDTH=80;
+static const size_t TERM_HEIGHT=25;
+
+static size_t terminal_row;
+static size_t terminal_column;
+
+static uint8_t current_color;
+static uint16_t* term_buffer;
+static uint16_t* const vga_buffer = (uint16_t*) 0xB8000;
+
+void screen_initialize(void) {
+
+	terminal_row = 0;
+	terminal_column = 0;
+	current_color = vga_color_set(LIGHT_GREY, BLACK);
+	term_buffer = vga_buffer;
+
+	for (size_t y = 0; y < TERM_HEIGHT; y++) {
+		for(size_t x = 0; x < TERM_WIDTH; x++) {
+			const size_t offset = y * TERM_WIDTH + x;
+			term_buffer[offset] = vga_entry(' ', current_color);
+		}
+	}
+}
+
+void term_setcolor(enum vga_colors color) {
+	current_color = color;
+}
+
+void term_putentryat (char c, uint8_t color, size_t x, size_t y) {
+	const size_t offset = y * TERM_WIDTH + x;
+	term_buffer[offset] = vga_entry(c, color);
+}
+
+void term_putchar(char c) {
+	unsigned char uc = c;
+
+	//Handle escaped characters, such as newline, and crtn.
+	switch (uc) {
+		case '\n':
+			terminal_column = 0;
+			terminal_row += 1;
+			break;
+		default:
+			term_putentryat(uc, current_color, terminal_column, terminal_row);
+			if (++terminal_column == TERM_WIDTH) {
+				terminal_column = 0;
+				if (++terminal_row == TERM_HEIGHT) {
+					term_scroll(false);
+					terminal_row = 0;
+				}
+			}
+			break;
+	}
+
+}
+
+struct csi_sequence parse_csi(const char* data, size_t size) {
+	enum State { PARAMETER, INTERMEDIATE, FINAL, INVALID };
+	enum State state = PARAMETER;
+
+	struct csi_sequence sequence = {
+		.parameter = NULL,
+		.parameter_len = 0,
+		.intermediate = NULL,
+		.intermediate_len = 0,
+		.final = NULL,
+		.valid = false
+	};
+
+	for (size_t j = 0; j < size; j++) {
+		uint8_t c = data[j];
+		if (state == PARAMETER && (c >= 0x30 && c <= 0x3F)) {
+			if (!sequence.parameter)
+				sequence.parameter = data + j;
+			sequence.parameter_len++;
+		} else if (c >= 0x20 && c <= 0x2F) {
+			if (!sequence.intermediate)
+				sequence.intermediate = data + j;
+			sequence.intermediate_len++;
+			state = INTERMEDIATE;
+		} else if (c >= 0x40 && c <= 0x7F) {
+			sequence.final = data + j;
+			sequence.valid = true;
+			state = FINAL;
+			break;
+		} else {
+			// Parameter found in intermediate byte location, or byte out of
+			// range
+			state = INVALID;
+			break;
+		}
+	}
+	return sequence;
+}
+
+void term_write(const char* data, size_t size) {
+	for(size_t i = 0; i < size; i++) {
+		//Begin handling ANSI escape codes.
+		if(data[i] == 0x1b) { //The current character is ESC - the start of ANSI codes.
+			//term_writes("ANSI Code encountered: ");
+
+			bool string_terminated = false; //Flag used in some of the escape codes
+
+			// TODO: Should only progress if we have at least 2 more bytes
+
+			switch ((uint8_t)data[i + 1]) {
+				case '[': //CSI - Control Sequence Introducer (The most common one, hence it comes first)
+					{
+						struct csi_sequence sequence = parse_csi(data + i + 2, size - (i + 2));
+						if (sequence.valid) {
+							// Send it off to our handler function to keep this part clean
+							handleControlSequence(sequence);
+							i += sequence.parameter_len + sequence.intermediate_len + 2; // Move past sequence
+						}
+					}
+					break;
+				//Single shifts are not handled, so just print them and exit
+				case 'N': //SS2 - Single Shift Two
+					term_writes("Single Shift Two\n");
+					break;
+				case 'O': //SS3 - Single Shift Three
+					term_writes("Single Shift Three\n");
+					break;
+
+				//Control Strings
+				case 'P': //DCS - Device Control String
+					term_writes("Device Control String");
+					string_terminated = false;
+					break;
+				case '\\': //ST - String Terminator 
+					term_writes("String Terminator\n");
+					string_terminated = true;
+					break;
+				case ']': //OSC - Operating System Command
+					term_writes("Operating System Command\n");
+					string_terminated = false;
+					break;
+				case 'X': //SOS - Start Of String
+					term_writes("Start of String");
+					string_terminated = false;
+					break;
+				case '^': //PM - Privacy Message
+					term_writes("Privacy Message\n");
+					break;
+				case '_': //APC - Application Program Command
+					term_writes("Application Program Command\n");
+					break;
+			}
+		} else {
+			term_putchar(data[i]);
+		}
+	}
+}
+
+void term_writes(const char* data) {
+	term_write(data, strlen(data));
+}
+
+void puts(const char* string) {
+	term_write(string, strlen(string));
+	term_putchar('\n');
+}
+
+void handleControlSequence(struct csi_sequence sequence) {
+	//Check for our failsafes
+
+	if (sequence.valid) {
+		int n = 0; //Default of the flag used for a few items
+
+		// Parse parameters, we only care about a max 2 of number only parameters
+		// for now
+		int params[2] = {0};
+		int param_count = 0;
+		if (sequence.parameter_len) {
+			for (size_t i = 0; i < sequence.parameter_len && param_count < 1; i++) {
+				char c = sequence.parameter[i];
+				if (isDigit(c)) {
+					n = (n*10) + (sequence.parameter[i] - '0');
+				} else if (c == ';') {
+					params[param_count++] = n;
+				}
+			}
+			params[param_count++] = n;
+		}
+
+		switch (*(sequence.final)) {
+			case 'H': case 'f': // CUP - Cursor Position
+				// TODO: Check to see if we have 2 paramaters
+				if (params[0]) params[0]--;
+				if (params[1]) params[1]--;
+				set_cursor(params[0], params[1]);
+				break;
+			case 'A': //CUU - Cursor Up
+				if (!params[0]) params[0] = 1;
+				set_cursor(terminal_column, terminal_row - params[0]);
+				break;
+			case 'B': //CUD - Cursor Down
+				if (!params[0]) params[0] = 1;
+				set_cursor(terminal_column, terminal_row + params[0]);
+				break;
+			case 'C': //CUF - Cursor Forward
+				if (!params[0]) params[0] = 1;
+				set_cursor(terminal_column + params[0], terminal_row);
+				break;
+			case 'D': //CUB - Cursor Back
+				if (!params[0]) params[0] = 1;
+				set_cursor(terminal_column - params[0], terminal_row);
+				break;
+			case 'E': //CNL - Cursor Next Line
+				if (!params[0]) params[0] = 1;
+				set_cursor(0, terminal_row + params[0]);
+				break;
+			case 'F': //CPL - Cursor Previous Line
+				if (!params[0]) params[0] = 1;
+				set_cursor(0, terminal_row - params[0]);
+				break;
+			case 'G': //CHA - Cursor Horizontal Absolute
+				if (params[0]) params[0]--;
+				set_cursor(params[0], terminal_row);
+				break;
+			case 'J': //ED - Erase in Display
+				//current cursor pos = y * width + x
+				{
+					int pos = terminal_row * 80 + terminal_column;
+					if (params[0] == 0) { // Clear from cursor to end of screen
+						for(; pos < (25 * 80); pos++) {
+							vga_buffer[pos] = '\0';
+						}
+					} else if(params[0] == 1) { // Clear from cursor to beginning
+						for(; pos > 0; pos--) {
+							vga_buffer[pos] = '\0';
+						}
+					} else if(params[0] == 2 || params[0] == 3) { // Clear entire screen
+						// TODO: Support scrollback buffer? (n = 3)
+						for(int i = 0; i < (25*80); i++) {
+							vga_buffer[0] = '\0';
+						}
+					}
+				}
+				break;
+			case 'K': //EL - Erase in Line
+				{
+					int pos = terminal_row * 80 + terminal_column;
+					if(params[0] == 0) { // From cursor to end of line
+						int endPos = (terminal_row + 1) * 80 - 1; // End of line = current row + 25 columns = current row + 1
+						for(; pos < endPos; pos++) {
+							vga_buffer[pos] = '\0';
+						}
+					} else if (params[0] == 1) { // From cursor to start of line
+						int endPos = terminal_row * 80; // Start of line = end of previous line + 1 == current line
+						for(; pos > endPos; pos--) {
+							vga_buffer[pos] = '\0';
+						}
+					} else if(params[0] == 2) { // Entire current line
+						pos = terminal_row * 80;
+						int endPos = (terminal_row + 1) * 80 - 1;
+						for(; pos < endPos; pos++) {
+							vga_buffer[pos] = '\0';
+						}
+					}
+				}
+				break;
+			case 'S': //SU - Scroll Up
+				term_scroll(true);
+				break;
+			case 'T': //SD - Scroll Down
+				term_scroll(false);
+				break;
+		}
+	}
+
+}
+
+bool isDigit(char c) {
+	return c >= '0' && c <= '9';
+}
+
+void set_cursor(int n, int m) {
+	terminal_column = n;
+	terminal_row = m;
+}
+
+void term_scroll(bool down) {
+
+	int current_pos;
+	if(down) {
+		current_pos = 25 * 80; //Start of the last line.
+	} else {
+		current_pos = 160; //Start of the second line.
+	}
+
+	unsigned char* term_buffer = (unsigned char*) vga_buffer;
+
+	if(down) { //To scroll down, move every character into the one below it, or "pull" every character down
+		while(current_pos > 80) {
+			term_buffer[current_pos + 160] = vga_buffer[current_pos];
+			term_buffer[current_pos + 159] = vga_buffer[current_pos - 1];
+			current_pos -= 2;
+		}
+	} else {
+		while (current_pos <= 4000) {
+			term_buffer[current_pos - 160 /*The character immediately below it*/] = vga_buffer[current_pos];      //Move each character up a line
+			term_buffer[current_pos - 159 /*The color of the character below*/] = vga_buffer[current_pos + 1];    //As well as its color
+			current_pos += 2; //Move to next char
+		}
+	}
+	
+	if(down) {
+		current_pos = 0; //Start of first line
+		for(; current_pos < 80; current_pos++) {
+			term_buffer[current_pos] = '\0';
+			current_pos += 2;
+		}
+	} else {
+		; //Start of the last line
+		//Wipe out the bottom line
+		for(current_pos = 3840; current_pos <= 3920; current_pos += 2) {
+			term_buffer[current_pos] = 0;
+		}
+	}
+	terminal_row = 24; //Start writing on the last line
+	terminal_column = 0;
+}
diff --git a/include/kernel/tty.h b/include/kernel/tty.h
index 25f63cf..503f424 100755
--- a/include/kernel/tty.h
+++ b/include/kernel/tty.h
@@ -1,18 +1,33 @@
-#pragma once
-
-#include <stddef.h>
-#include <stdint.h>
-#include <vga.h>
-
-void term_setcolor(enum vga_colors);
-void screen_initialize(void);
-void term_putentryat(char, uint8_t, size_t, size_t);
-void term_putchar(char);
-void term_write(const char*, size_t);
-void term_writes(const char*);
-void puts(const char*);
-void set_cursor(int, int);
-void term_scroll(void);
-void int_to_ascii(int, char*);
-void int_to_hex(int, char*);
-void empty_string(char*);
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include "vga.h"
+
+struct csi_sequence {
+	const char* parameter;
+	size_t parameter_len;
+	const char* intermediate;
+	size_t intermediate_len;
+	const char* final;
+	bool valid;
+};
+
+
+void term_setcolor(enum vga_colors);
+void screen_initialize(void);
+void term_putentryat(char, uint8_t, size_t, size_t);
+void term_putchar(char);
+void term_write(const char*, size_t);
+void term_writes(const char*);
+void puts(const char*);
+void handleControlSequence(struct csi_sequence);
+void set_cursor(int, int);
+void term_scroll(bool);
+void int_to_ascii(int, char*);
+void int_to_hex(int, char*);
+void empty_string(char*);
+
+bool isDigit(char c);