/* Based off of code from Leonard Kevin McGuire Jr (www.kmcg3413.net) ([email protected]) http://wiki.osdev.org/User:Pancakes/BitmapHeapImplementation */ void main_heap_init() { kheap_init(&main_heap); for (uint8_t i = 0; i < 15; i++) { void * block = memory_alloc_page(0); kheap_add_block(&main_heap, (uint32_t) block, PAGE_SIZE, 16); } }
int pagetable_map( struct pagetable *p, unsigned vaddr, unsigned paddr, int flags )
{
struct pagetable *q;
struct pageentry *e;
unsigned a = vaddr>>22;
unsigned b = (vaddr>>12) & 0x3ff;
if(flags&PAGE_FLAG_ALLOC) {
paddr = (unsigned) memory_alloc_page(0);
if(!paddr) return 0;
}
e = &p->entry[a];
if(!e->present) {
q = pagetable_create();
if(!q) return 0;
e->present = 1;
e->readwrite = 1;
e->user = (flags&PAGE_FLAG_KERNEL) ? 0 : 1;
e->writethrough = 0;
e->nocache = 0;
e->accessed = 0;
e->dirty = 0;
e->pagesize = 0;
e->globalpage = (flags&PAGE_FLAG_KERNEL) ? 1 : 0;
e->avail = 0;
e->addr = (((unsigned)q) >> 12);
} else {
void memory_init() {
int i;
pages_total = (total_memory * 1024) / (PAGE_SIZE / 1024);
pages_free = pages_total;
console_printf("memory: %d MB (%d KB) total\n",
(pages_free * PAGE_SIZE) / MEGA,
(pages_free * PAGE_SIZE) / KILO);
freemap = alloc_memory_start;
freemap_bits = pages_total;
freemap_bytes = 1 + freemap_bits / 8;
freemap_cells = 1 + freemap_bits / CELL_BITS;
freemap_pages = 1 + freemap_bytes / PAGE_SIZE;
console_printf("memory: %d bits %d bytes %d cells %d pages\n",
freemap_bits, freemap_bytes, freemap_cells, freemap_pages);
memset(freemap, 0xff, freemap_bytes);
for (i = 0; i < freemap_pages; i++) {
memory_alloc_page(0);
}
// This is ahack that I don't understand yet.
// vmware doesn't like the use of a particular page
// close to 1MB, but what it is used for I don't know.
freemap[0] = 0x0;
console_printf("memory: %d MB (%d KB) available\n",
(pages_free * PAGE_SIZE) / MEGA,
(pages_free * PAGE_SIZE) / KILO);
}
void memory_init() {
int i;
memory_detect_map();
pages_total = (total_memory * 1024) / (PAGE_SIZE / 1024);
pages_free = pages_total;
console_printf("memory: %d MB (%d KB) total\n",
(pages_free * PAGE_SIZE) / MEGA,
(pages_free * PAGE_SIZE) / KILO);
// Freemap is organized as follows
// Each page is represented as one bit
// Each cell in the freemap is 32 bits, representing 32 pages
freemap = alloc_memory_start;
freemap_bits = pages_total;
freemap_bytes = 1 + freemap_bits / 8;
freemap_cells = 1 + freemap_bits / CELL_BITS;
freemap_pages = 1 + freemap_bytes / PAGE_SIZE;
console_printf("memory: %d bits %d bytes %d cells %d pages\n",
freemap_bits, freemap_bytes, freemap_cells, freemap_pages);
memset(freemap, 0xff, freemap_bytes);
for (i = 0; i < freemap_pages; i++) {
memory_alloc_page(0);
}
// This is ahack that I don't understand yet.
// vmware doesn't like the use of a particular page
// close to 1MB, but what it is used for I don't know.
freemap[0] = 0x0;
// VirtualBox doesn't like memory address 0x1A0000 through 0x1C0000
// so block it off
freemap[5] = 0x0;
console_printf("memory: %d MB (%d KB) available\n",
(pages_free * PAGE_SIZE) / MEGA,
(pages_free * PAGE_SIZE) / KILO);
}
struct pagetable * pagetable_create()
{
return memory_alloc_page(1);
}
