void initialize_paging(uint32_t memsize)
{
nframes = memsize / 4;
frames = (uint32_t *)kmalloc(INDEX_FROM_BIT(nframes));
uintptr_t pg;
assert(frames != NULL);
memset(frames, 0, INDEX_FROM_BIT(nframes));
uintptr_t physical;
kernel_directory = (page_directory_t *)kmalloc_ap(sizeof(page_directory_t), &physical);
memset(kernel_directory, 0, sizeof(page_directory_t));
current_directory = kernel_directory;
#if 1
get_page(0,1,kernel_directory)->present = 0;
set_frame(0);
for(uintptr_t i = 0x1000; i < placement_address+0x3000; i += 0x1000)
#else
for(uintptr_t i = 0x0; i < placement_address+0x3000; i += 0x1000)
#endif
{
direct_frame( get_page(i, 1, kernel_directory), 1, 0, i);
}
kernel_directory->physical_addr = (uintptr_t)kernel_directory->tables_physical;
uintptr_t heap_start = KERNEL_HEAP_START;
if(heap_start <= placement_address + 0x3000)
{
heap_start = placement_address + 0x100000;
}
for (uintptr_t i = placement_address + 0x3000; i < heap_start; i += 0x1000)
{
alloc_frame(get_page(i, 1, kernel_directory), 1, 0);
}
for(uintptr_t i = heap_start; i < heap_start + KERNEL_HEAP_INIT; i += 0x1000)
{
get_page(i, 1, kernel_directory);
}
for(uintptr_t i = heap_start; i < heap_start + KERNEL_HEAP_INIT; i += 0x1000)
{
alloc_frame(get_page(i, 1, kernel_directory), 0, 0);
}
register_isr_handler(13, general_protection_fault);
register_isr_handler(14, page_fault);
switch_page_directory(kernel_directory);
kernel_heap = create_heap(heap_start, heap_start + KERNEL_HEAP_INIT, KERNEL_HEAP_END, 0, 0);
//kernel_heap = create_heap(heap_start, KERNEL_HEAP_END, KERNEL_HEAP_END, 0, 0);
}
void init_timer(u32 freq)
{
register_isr_handler(IRQ0, &timer_callback);
u32 divisor = 1193180 / freq;
outb(TIMER_CMD, 0x36);
outb(TIMER_CHAN1, divisor & 0xFF);
outb(TIMER_CHAN1, (divisor >> 8) & 0xFF);
}
