Implemented VMM!

kernel/src/vmm.c

@@ -0,0 +1,77 @@
+#include <bitmap.h>
+#include <kernel.h>
+#include <paging.h>
+#include <pmm.h>
+
+#include <vmm.h>
+
+#include <string.h>
+
+bitmap_t vmm_bitmap;
+
+int vmm_init(void) {
+	vmm_bitmap.ready = 0;
+	vmm_bitmap.membase = KERNEL_HEAP_BASE;
+	vmm_bitmap.blocks = dceil(KERNEL_HEAP_SIZE, BLOCK_SIZE);
+	vmm_bitmap.bytes = dceil(vmm_bitmap.blocks, 8);
+	uint32_t bitmaploc = 0xC6000000;
+
+	debugf("%d blocks in %d bytes\n", vmm_bitmap.blocks, vmm_bitmap.bytes);
+	size_t pagecount = dceil(vmm_bitmap.bytes, PAGE_SIZE);
+	for (size_t i = 0; i < pagecount; i++) {
+		void* fr = pmm_allocPage();
+		debugf("Allocating page %d/%d...\n", i+1, pagecount);
+		if (fr == NULL) return 1;
+		debugf("Mapping page at 0x%08x to 0x%08x\n", fr, bitmaploc + i * PAGE_SIZE);
+		pag_mapPage(bitmaploc + i * PAGE_SIZE, (uint32_t)fr, 0);
+	}
+
+	// Set all pages as
+	vmm_bitmap.map = (void*)bitmaploc;
+	bmap_setall(&vmm_bitmap, 0);
+
+	bmap_set(&vmm_bitmap, 0, 1);
+	bmap_set(&vmm_bitmap, 8, 1);
+
+	debugf(
+		"[vmm] Virtual memory manager initialized.\n"
+		"\tBitmap manages %d blocks\n"
+		"\tBitmap is at 0x%08x in virtual memory\n"
+		"\tBitmap is %d bytes over %d pages\n",
+		vmm_bitmap.blocks, vmm_bitmap.map,
+		vmm_bitmap.bytes, pagecount
+	      );
+
+	vmm_bitmap.ready = 1;
+	return 0;
+}
+
+void* vmm_alloc(size_t pages) {
+	size_t idx = bmap_findarea(&vmm_bitmap, pages, 0);
+	if (idx == BMAP_NOT_FOUND) return NULL;
+	void* ptr = bmap_ptr(&vmm_bitmap, idx);
+
+	bmap_setarea(&vmm_bitmap, idx * BLOCK_SIZE, pages * PAGE_SIZE, 1);
+
+	for (size_t i = 0; i < pages; i++) {
+		void* fr = pmm_allocPage();
+		if (fr == NULL) return NULL;
+		pag_mapPage((uint32_t)ptr + i * PAGE_SIZE, (uint32_t)fr, 0);
+	}
+
+	return ptr;
+}
+
+void vmm_free(void* ptr, size_t pages) {
+	for (size_t i = 0; i < pages; i++) {
+		uint32_t vaddr = (uint32_t)ptr + i * PAGE_SIZE;
+		uint32_t paddr = (uint32_t)pag_virtToPhys((uint32_t)ptr);
+		
+		pmm_freePage((void*)paddr);
+		pag_umapPage(vaddr);
+	}
+
+	size_t base = ((size_t)ptr - KERNEL_BASE) / BLOCK_SIZE;
+	bmap_setarea(&vmm_bitmap, base, pages, 0);
+}
+