kernel

/*
    - returning from kernel_main causes a triple fault
*/
#include "kernel.h"
void kernel_main(void);
void print(char*);
void* memcpy(void*,void*,int);

static int x=0;
static shortbuf term=vga_mem;
static int ti=5,tx=5,ty=0;
/* static data is collected in the .data section
    -> this might be broken: references to x go to ds:0x40! (that is 0x0000000000000040!!)
*/
void kernel_main(void) {
    /* on entry: push ebp, mov esp to ebp, esp:=esp-(size of local vars) */
    /* local variables are collected on the stack as follows:
        mov REG,<value>         /   lea REG,[ebp-<i>]   (to store an address)
        mov [ebp-<i>],REG           mov [ebp-<j>],REG
    */
    volatile char s[30]="volatile!";
    print((void*)s);
    /*for(x=10; x<20; x++) {
        term[x]=vga_entry(str[x],vga_color(vga_red,vga_lightgrey));
    }
    for(x=20;x<500;x++){
        term[x]=vga_entry('X',vga_color(vga_cyan,vga_black));
    }
    hang();
    while(1);*/
    return;
    /* on exit: esp:=esp+(size of local vars), pop ebp */
}

void print(char *p) {
    int x=0;
    for(x=0; p[x]; x++) {
        /*if(++tx==vga_width) {
            ty+=1;
            tx=0;
        }*/
        term[ti++]=vga_entry(p[x],vga_color(vga_white,vga_black));
        /*term[ti++]=p[x];*/
    }
}

/* required user-supplied functions */
void* memcpy(void *dest,void *src,int count) {
    if(count==0) return dest;
    /*byte *dp=(byte*)dest;
    byte *sp=(byte*)src;*/
    ((byte*)dest)[count]=((byte*)src)[count];
    return memcpy(((byte*)dest)+1,((byte*)src)+1,count-1);
}