Screen driver

os/cpu/timer.c

@@ -1,5 +1,10 @@
+#include "timer.h"
 #include "types.h"
 
+// DEBUGGING ONLY
+#include "../libc/string.h"
+#include "../drivers/serial.h"
+
 #define TIMER_FREQUENCY 385803 // 1000/s
 
 typedef struct
@@ -9,7 +14,7 @@ typedef struct
 	void (*f)();
 } Callback;
 
-long long timer_count = 0;
+volatile long long timer_count = 0;
 
 Callback callbacks[255];
 unsigned char callbackCount = 0;
@@ -32,10 +37,12 @@ void timer_interrupt(/* Registers *r */)
 	}
 }
 
-void sleep(long delay) //ms
+void sleep(long long delay) //ms
 {
 	long long targetCount = delay * TIMER_FREQUENCY / 1000000 + timer_count;
-	while(timer_count < targetCount) {}
+	while(timer_count < targetCount)
+	{
+	}
 }
 
 // Note this runs within the timer interrupt,

os/cpu/timer.h

@@ -1,3 +1,8 @@
+#ifndef CPU_TIMER_H
+#define CPU_TIMER_H
+
 void sleep(long long delay);
 int timer_callmelater(void (*f)(), long period);
 int timer_stopcallingme(unsigned char position);
+
+#endif

os/drivers/screen.c

@@ -0,0 +1,134 @@
+#include <stdint.h>
+#include "serial.h"
+
+// https://www.buydisplay.com/download/democode/ERM24064-1_DemoCode.txt
+
+volatile uint8_t *const SCREEN_ADDRESS_DATA = (uint8_t *)0xf40001;
+volatile uint8_t *const SCREEN_ADDRESS_INSTR = (uint8_t *)0xf40003;
+
+// Wait for read and write to not be busy
+void lcd_checkBusy_S0S1()
+{
+	uint8_t b;
+	do
+	{
+		b = *SCREEN_ADDRESS_INSTR;
+	} while((b & 0x03) != 0x03);
+}
+
+// Wait for auto write to not be busy
+void lcd_checkBusy_S3()
+{
+	uint8_t b;
+	do
+	{
+		b = *SCREEN_ADDRESS_INSTR;
+	} while((b & 0x08) != 0x08);
+}
+
+void lcd_writeData(uint8_t data)
+{
+	*SCREEN_ADDRESS_DATA = data;
+}
+
+uint8_t lcd_readData()
+{
+	return *SCREEN_ADDRESS_DATA;
+}
+
+void lcd_writeCommand(uint8_t data1, uint8_t data2, uint8_t instruction, int numParameters)
+{
+	if(numParameters >= 1)
+	{
+		lcd_checkBusy_S0S1();
+		lcd_writeData(data1);
+	}
+
+	if(numParameters == 2)
+	{
+		lcd_checkBusy_S0S1();
+		lcd_writeData(data2);
+	}
+
+	// lcd_checkBusy_S3();
+
+	*SCREEN_ADDRESS_INSTR = instruction;
+}
+
+uint8_t lcd_readByte()
+{
+	lcd_writeCommand(0, 0, 0xc5, 0);
+	lcd_checkBusy_S0S1();
+	return lcd_readData();
+}
+
+void lcd_setPos(uint8_t x, uint8_t y, uint8_t mode)
+{
+	if(mode)
+	{
+		// graphics
+		int a = y * 40 + x;
+		uint8_t aLwr = a & 0xff;
+		uint8_t aUpr = a >> 8;
+		lcd_writeCommand(aLwr, aUpr + 0x08, 0x24, 2);
+	}
+	else
+	{
+		// text
+		int a = y * 40 + x;
+		uint8_t aLwr = a & 0xff;
+		uint8_t aUpr = a >> 8;
+		lcd_writeCommand(aLwr, aUpr, 0x24, 2);
+	}
+}
+
+void lcd_init()
+{
+	lcd_writeCommand(0, 0, 0x40, 2); // Set text home address
+	lcd_writeCommand(40, 0, 0x41, 2); // Set text area width
+	lcd_writeCommand(0, 0x08, 0x42, 2); // Set graphics home address
+	lcd_writeCommand(40, 0, 0x43, 2); // Set graphics area width
+	lcd_writeCommand(0, 0, 0xa7, 0); // 8-line cursor
+	lcd_writeCommand(0, 0, 0x80, 0); // OR mode
+	lcd_writeCommand(0, 0, 0x9c, 0); // text & graphics on
+}
+
+void lcd_clear()
+{
+	lcd_setPos(0, 0, 0);
+	lcd_writeCommand(0, 0, 0xb0, 0);
+	for(int i = 0; i < 8192; i++)
+	{
+		lcd_writeData(0);
+	}
+	lcd_writeCommand(0, 0, 0xb2, 0);
+}
+
+void lcd_writeString(uint8_t x, uint8_t y, char *str)
+{
+	lcd_setPos(x, y, 0);
+	while(*str != 0)
+	{
+		lcd_writeCommand(*str - 0x20, 0, 0xc0, 1);
+		str++;
+	}
+}
+
+// Very slow. Use sparingly
+void lcd_setpixel(uint8_t x, uint8_t y, uint8_t value)
+{
+	int byteX = x / 6; // 6 bits per character
+	int bit = 5 - (x - byteX * 6);
+	lcd_setPos(byteX, y, 1);
+	uint8_t curValue = lcd_readByte();
+	if(value)
+	{
+		curValue |= 1 << bit;
+	}
+	else
+	{
+		curValue &= ~(1 << bit);
+	}
+	
+	lcd_writeCommand(curValue, 0, 0xc4, 1);
+}

os/drivers/screen.h

@@ -0,0 +1,6 @@
+#include <stdint.h>
+
+void lcd_init();
+void lcd_clear();
+void lcd_writeString(uint8_t x, uint8_t y, char *str);
+void lcd_setpixel(uint8_t x, uint8_t y, uint8_t value);

os/libc/stdlib.c

@@ -47,7 +47,7 @@ unsigned long long strtol(const char *str, char **str_end, unsigned int base)
 	//base 10 only - temp
 	unsigned char c = str[i];
 	if(c >= 'a') c -= 0x20; //lowercase
-	if(c >= '9') c -= 0x37; //to int
+	if(c > '9') c -= 0x37; //to int
 	else c -= '0';
 	while(c < base && str[i] != 0)
 	{

os/main.c

@@ -1,6 +1,8 @@
 #include "drivers/serial.h"
 #include "drivers/keyboard.h"
+#include "drivers/screen.h"
 #include "prog/tty.h"
+#include "cpu/timer.h"
 
 void kmain()
 {
@@ -16,6 +18,14 @@ void kmain()
 	serial_print(0, "    \\/  \\/   |_____|_| \\_|_____/|_|    |______\\____/   \\/  \\/   |______|_|  \\_\\  \\____/|_____/\r\n");
 	serial_print(0, "===================================================================================================\r\n");
 	serial_print(0, "www.scd31.com\r\n");
+
+	lcd_init();
+	sleep(1000);
+	lcd_clear();
+	sleep(1000);
+	lcd_writeString(3, 4, "Hello world!");
+
+	serial_print(0, "LCD initialized.\r\n");
 	
 	//keyboard_init();
 	tty_init();

os/prog/tty.c

@@ -7,6 +7,7 @@
 #include "../libc/string.h"
 #include "../libc/stdlib.h"
 #include "../drivers/serial.h"
+#include "../drivers/screen.h"
 
 #define BUFFER_LEN 1023
 
@@ -59,6 +60,7 @@ void tty_putchar(char c)
 	serial_putchar(0, c);
 }
 
+// TODO why do we disable optimizations? I don't remember
 #pragma GCC push_options
 #pragma GCC optimize("O0")
 void tty_process(char *buf)
@@ -87,27 +89,8 @@ void tty_process(char *buf)
 		tty_print("\r\n");
 
 		char buffer[100];
-		
-		//sprintf(buffer, "Hello! %X\r\n", 0xDEADB33F);
-		//tty_print(buffer);
-
-		//long long a = 0xD;
-		//long long b = 0x13BEEF;
-		//sprintf(buffer, "abcdefg: %X %X %X\r\n", a, b, a * b);
-
-		//if(a * b == 0)
-		//{
-		//	tty_print("Yes, it is 0");
-		//}
-
-		//tty_print(buffer);
 			
 		unsigned char *ptr = (unsigned char *)(unsigned long)strtol(arg, NULL, 0);
-
-		if(ptr == 0xB33F)
-		{
-			tty_print("It is 0xB33F\r\n");
-		}
 		
 		sprintf(buffer, "%X\r\n", (unsigned long long) *ptr);
 		tty_print(buffer);
@@ -129,6 +112,34 @@ void tty_process(char *buf)
 		char *addr = (char *)(long)strtol(addrStr, NULL, 0);
 		*addr = (char)valL;
 	}
+	else if(strcmp(cmd, "print") == 0)
+	{
+		char *xStr = strtok(NULL, " ");
+		char *yStr = strtok(NULL, " ");
+		char *text = strtok(NULL, " ");
+		if(!(xStr && yStr && text))
+		{
+			tty_print("Usage: print X Y STRING");
+			return;
+		}
+		int x = strtol(xStr, NULL, 0);
+		int y = strtol(yStr, NULL, 0);
+		lcd_writeString(x, y, text);
+	}
+	else if(strcmp(cmd, "pixel") == 0)
+	{
+		char *xStr = strtok(NULL, " ");
+		char *yStr = strtok(NULL, " ");
+		if(!(xStr && yStr))
+		{
+			tty_print("Usage: pixel X Y");
+			return;
+		}
+		int x = strtol(xStr, NULL, 0);
+		int y = strtol(yStr, NULL, 0);
+
+		lcd_setpixel(x, y, 1);
+	}
 	else
 	{
 		tty_print("Unknown command. Type help for help.\r\n");

os/start.s

@@ -39,17 +39,29 @@
 
 	.long 0x17FFFE /* SP at top of 256K of RAM - but it has to be an even address */
 	.long _start
+	.long generic_error /* Bus error */
+	.long generic_error /* Address error */
+	.long generic_error /* Illegal instruction */
+	.long generic_error /* Zero divide */
+	.long generic_error /* CHK instruction */
+	.long generic_error /* TRAPV instruction */
+	.long generic_error /* Privilege violation */
+	.long generic_error /* Trace */
 
 	.org 0x100
 	.long timer_int
+
+	.rept 0xBF
+	.long generic_error
+	.endr
 	
 	.org 0x400
 _start:
 	/* Enable interrupts */
-	/* ANDI.W #0xF8FF, %sr */
+	ANDI.W #0xF8FF, %sr
 
 	/* Disable interrupts */
-	ORI.W #0x700, %sr
+	/* ORI.W #0x700, %sr */
 	
 	JSR kmain
 
@@ -74,3 +86,5 @@ timer_int:
 	/* return */
 	RTE
 	
+generic_error:
+	RTE

os/tests/main.c

@@ -104,6 +104,9 @@ void test_strtol()
 {
 	assert_long(123, strtol("123", 0, 0));
 	assert_long(0x456, strtol("0x456", 0, 0));
+	assert_long(0xa, strtol("0xa", 0, 0));
+	assert_long(0xa, strtol("0xA", 0, 0));
+	assert_long(9, strtol("9", 0, 0));
 }
 
 void test_muldi3()