pmm.c

1 files changed, 49 insertions, 0 deletions

diff --git a/kernel/src/mem/pmm.c b/kernel/src/mem/pmm.c
new file mode 100644
index 0000000..63bfb07
--- /dev/null
+++ b/kernel/src/mem/pmm.c
@@ -0,0 +1,49 @@
+#include <paging.h>
+#include <heap.h>
+#include <libk/list.h>
+#include <libk/stdio.h>
+#include <libk/serial_stdio.h>
+#include <libk/string.h>
+#include <multiboot2.h>
+#include <pmm.h>
+
+#define PMM_PAGE_SIZE 4096 * 512
+#define MEM_USED_BELOW 0x03000000
+
+uint64_t free_mem_cnt;
+uint64_t all_mem_cnt;
+list_t pmm_list;
+
+void init_pmm()
+{
+	INIT_LIST(pmm_list);
+
+	mmap_t* pos;
+	list_for_each_entry_prev(pos, (&mmap.list), list) {
+		mb2_tag_mmap_entry entry = pos->mmap_entry;
+		if (entry.type != 1)
+			continue;
+		uint64_t base = entry.base_addr & (PMM_PAGE_SIZE - 1) ? (entry.base_addr & (uint64_t)~(PMM_PAGE_SIZE - 1)) + PMM_PAGE_SIZE : entry.base_addr;
+		for (uint64_t i = base; i + PMM_PAGE_SIZE <= entry.base_addr + entry.length; i += PMM_PAGE_SIZE) {
+			if (i >= MEM_USED_BELOW) {
+				free_mem_cnt++;
+				map_addr(i, i, FLAG_PRESENT);
+				list_t* list = (list_t*)i;
+				add_to_list(list, &pmm_list, pmm_list.next);
+			}
+		}
+	}
+	all_mem_cnt = free_mem_cnt;
+
+	// print addr of every free block of memory
+	//list_t* pok;
+	//list_for_each(pok, (&pmm_list)) {
+	//	serial_printf("0x%x\n", pok);
+	//}
+}
+
+void memory_usage()
+{
+	printf("memory used: %dMB\n", (48 * 1024 * 1024 + (all_mem_cnt - free_mem_cnt) * PAGE_SIZE) / 1024 / 1024);
+	printf("memory free: %dMB\n", free_mem_cnt * PAGE_SIZE / 1024 / 1024);
+}