#include "kmalloc.h"

#include "kernel.h"
#include "spinlock.h"

static uint8_t    data[KMALLOC_MEM_SIZE]; // bytes

static uint32_t   next;
static uint32_t   first;
static uint8_t    init=0;

// will be initialized on first call to kballoc() //
static void kmallocinit()
{
    next=&(data[0]);
    first=next;

    //TODO: optionally tell gcc to align this itself.
    if(next%4096) 
    {
        next+=4096; 
        next/=4096;
        next*=4096;
    }
    //

    klog("kmalloc_init: 0x%08X",next);
    init=1;
}

// kernel block memory allocation //
uint32_t kballoc(uint32_t size)
{
    size*=4096;
    
    spinlock_spin(SPINLOCK_ALLOC);

	if(!init)kmallocinit();

	uint32_t old=next;
	next+=size;

    spinlock_release(SPINLOCK_ALLOC);

    if(next>=first+KMALLOC_MEM_SIZE)
    {
        kpanic("kballoc ran out of memory! maybe increase KMALLOC_MEM_SIZE in kmalloc.c?");
    }

    klog("(%d) : 0x%08X (~%dKB left)",size,old,(KMALLOC_MEM_SIZE-next+first)/1024);
    return old;
}

//TODO: allow freeing memory!!
uint32_t kbfree(uint32_t pos)
{
        kpanic("kbfree NOT IMPLEMENTED YET");
}