kernel: initial vmm implementation

kernel-src/arch/x86-64/main.c

@@ -6,6 +6,7 @@
 #include <kernel/term.h>
 #include <kernel/pmm.h>
 #include <arch/mmu.h>
+#include <kernel/vmm.h>
 
 static cpu_t bsp_cpu;
 
@@ -19,5 +20,6 @@ void kernel_entry() {
 	term_init();
 	logging_sethook(term_putchar);
 	arch_mmu_init();
+	vmm_init();
 	__assert(!"kernel entry end");
 }

kernel-src/arch/x86-64/mmu.c

@@ -69,7 +69,7 @@ static bool add_page(pagetableptr_t top, void *vaddr, uint64_t entry, int depth)
 		pdpt = pmm_alloc(1, PMM_SECTION_DEFAULT);
 		if (pdpt == NULL)
 			return false;
-		pml4[pml4offset] = (uint64_t)FROM_HHDM(pdpt) | INTERMEDIATE_FLAGS;
+		pml4[pml4offset] = (uint64_t)pdpt | INTERMEDIATE_FLAGS;
 		pdpt = MAKE_HHDM(pdpt);
 		memset(pdpt, 0, PAGE_SIZE);
 	}