Initial commit

src/main.c

@@ -0,0 +1,97 @@
+#include "../include/system.h"
+#include "../include/gdt.h"
+#include "../include/idt.h"
+#include "../include/scrn.h"
+
+unsigned char *memcpy(unsigned char *dest, const unsigned char *src, int count)
+{
+    /* Add code here to copy 'count' bytes of data from 'src' to
+    *  'dest', finally return 'dest' */    
+	const char *sp = (const char *)src;
+    char *dp = (char *)dest;
+    for(; count != 0; count--) *dp++ = *sp++;
+    return dest;
+}
+
+unsigned char *memset(unsigned char *dest, unsigned char val, int count)
+{
+    /* Add code here to set 'count' bytes in 'dest' to 'val'.
+    *  Again, return 'dest' */
+    char *temp = (char *)dest;
+    for( ; count != 0; count--) *temp++ = val;
+    return dest;
+}
+
+unsigned short *memsetw(unsigned short *dest, unsigned short val, int count)
+{
+    /* Same as above, but this time, we're working with a 16-bit
+    *  'val' and dest pointer. Your code can be an exact copy of
+    *  the above, provided that your local variables if any, are
+    *  unsigned short */
+    unsigned short *temp = (unsigned short *)dest;
+    for( ; count != 0; count--) *temp++ = val;
+    return dest;
+}
+
+int strlen(const char *str)
+{
+    /* This loops through character array 'str', returning how
+    *  many characters it needs to check before it finds a 0.
+    *  In simple words, it returns the length in bytes of a string */
+    //size_t retval;
+	unsigned int retval;
+    for(retval = 0; *str != '\0'; str++) retval++;
+    return retval;
+}
+
+/* We will use this later on for reading from the I/O ports to get data
+*  from devices such as the keyboard. We are using what is called
+*  'inline assembly' in these routines to actually do the work */
+unsigned char inportb (unsigned short _port)
+{
+    unsigned char rv;
+    __asm__ __volatile__ ("inb %1, %0" : "=a" (rv) : "dN" (_port));
+    return rv;
+}
+
+/* We will use this to write to I/O ports to send bytes to devices. This
+*  will be used in the next tutorial for changing the textmode cursor
+*  position. Again, we use some inline assembly for the stuff that simply
+*  cannot be done in C */
+void outportb (unsigned short _port, unsigned char _data)
+{
+    __asm__ __volatile__ ("outb %1, %0" : : "dN" (_port), "a" (_data));
+}
+
+extern char __BUILD_DATE;
+extern char __BUILD_NUMBER;
+
+/* This is a very simple main() function. All it does is sit in an
+*  infinite loop. This will be like our 'idle' loop */
+void main()
+{
+    /* You would add commands after here */
+	init_video();
+	puts("Video initialized.\n");
+	gdt_install();
+	puts("Global Descriptor Table initialized.\n");
+	idt_install();
+	puts("Interrupt Descriptor Table initialized.\n");
+	isrs_install();
+	puts("Interrupt Service Routines installed.\n");
+	irq_install();
+	__asm__ __volatile__ ("sti");
+	puts("Interrupt Requests now allowed.\n");
+	//timer_install();
+	//puts("Installed Timer.\n");
+	kb_install();
+	puts("Keyboard installed.\n");
+	puts("SDOS version 0.0.0.1 initialized.\n");
+	//puts(&__BUILD_DATE);
+	//puts(&__BUILD_NUMBER);
+	//puts("Divide by zero check:\n");
+	//puts(5 / 0);
+    /* ...and leave this loop in. There is an endless loop in
+    *  'start.asm' also, if you accidentally delete this next line */
+    for (;;);
+}