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#include "mem.h"
#include <core/sys.h>
#include <core/monitor.h>
#include "paging.h"
#include <config.h>
#ifdef K_USE_BASIC_HEAP
#include "heap.basic.h"
#else
#include "heap.std.h"
#endif
#include "mem.h"
#define FREEPAGESTOKEEP 5
#define KHEAP_IDXSIZE 0x4000 // only used with heap.std.h
#define KHEAP_INITSIZE 0x00080000
#define KHEAP_MAXSIZE 0x08000000
size_t mem_placementAddr;
static uint32_t kheap_working = 0;
// ******************************
// PAGE ALLOCATION
// ****************************
static struct freepage {
size_t virt, phys;
} freepages[FREEPAGESTOKEEP];
uint32_t freepagecount = 0;
/* For internal use only. Populates the cache of pages that can be given to requesters. */
static void get_free_pages() {
static uint32_t locked = 0;
uint32_t i;
if (locked) return;
locked = 1;
while (freepagecount < FREEPAGESTOKEEP) {
if (kheap_working) {
for (i = 0xFFFFF000; i >= 0xF0000000; i -= 0x1000) {
if (pagedir_getPage(kernel_pagedir, i, 1)->frame == 0) break;
}
freepages[freepagecount].virt = i;
freepages[freepagecount].phys = frame_alloc() * 0x1000;
page_map(pagedir_getPage(kernel_pagedir, i, 0), freepages[freepagecount].phys / 0x1000, 0, 0);
freepagecount++;
} else {
if (mem_placementAddr & 0xFFFFF000) {
mem_placementAddr &= 0xFFFFF000;
mem_placementAddr += 0x1000;
}
freepages[freepagecount].virt = (size_t)kmalloc(0x1000);
freepages[freepagecount].phys = freepages[freepagecount].virt - K_HIGHHALF_ADDR;
freepagecount++;
}
}
locked = 0;
}
/* Gives one page from the cache to someone requesting it. */
void* kmalloc_page(size_t *phys) {
cli();
get_free_pages();
freepagecount--;
*phys = freepages[freepagecount].phys;
size_t tmp = freepages[freepagecount].virt;
sti();
return (void*)tmp;
}
void kfree_page(void* ptr) {
size_t addr = (size_t)ptr;
if (kheap_working) { //With this we can know if paging works
page_unmapFree(pagedir_getPage(kernel_pagedir, addr, 0));
}
}
//***********************************
// NORMAL MEMORY ALLOCATION
// *************************
static struct heap kheap;
/* Called on kernel start. Creates the kernel heap. */
void kheap_init() {
#ifdef K_USE_BASIC_HEAP
heap_create(&kheap, (mem_placementAddr & 0xFFFFF000) + 0x1000, KHEAP_INITSIZE, KHEAP_MAXSIZE);
#else
heap_create(&kheap, (mem_placementAddr & 0xFFFFF000) + 0x1000, KHEAP_IDXSIZE, KHEAP_INITSIZE, KHEAP_MAXSIZE);
#endif
kheap_working = 1;
monitor_write("[KHeap] ");
}
/* Allocates on the heap if possible. If not possible, allocates just after the kernel code. */
void* kmalloc(size_t size) {
if (kheap_working) {
return heap_alloc(&kheap, size);
} else {
size_t tmp = mem_placementAddr;
mem_placementAddr += size;
return (void*)tmp;
}
}
void kfree(void* ptr) {
if (kheap_working) {
heap_free(&kheap, ptr);
}
}
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