diff --git a/core/errno.h b/core/errno.h
new file mode 100644
index 0000000..c805673
--- /dev/null
+++ b/core/errno.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#define	EPERM		 1	/* Operation not permitted */
+#define	ENOENT		 2	/* No such file or directory */
+#define	ESRCH		 3	/* No such process */
+#define	EINTR		 4	/* Interrupted system call */
+#define	EIO		 5	/* I/O error */
+#define	ENXIO		 6	/* No such device or address */
+#define	E2BIG		 7	/* Argument list too long */
+#define	ENOEXEC		 8	/* Exec format error */
+#define	EBADF		 9	/* Bad file number */
+#define	ECHILD		10	/* No child processes */
+#define	EAGAIN		11	/* Try again */
+#define	ENOMEM		12	/* Out of memory */
+#define	EACCES		13	/* Permission denied */
+#define	EFAULT		14	/* Bad address */
+#define	ENOTBLK		15	/* Block device required */
+#define	EBUSY		16	/* Device or resource busy */
+#define	EEXIST		17	/* File exists */
+#define	EXDEV		18	/* Cross-device link */
+#define	ENODEV		19	/* No such device */
+#define	ENOTDIR		20	/* Not a directory */
+#define	EISDIR		21	/* Is a directory */
+#define	EINVAL		22	/* Invalid argument */
+#define	ENFILE		23	/* File table overflow */
+#define	EMFILE		24	/* Too many open files */
+#define	ENOTTY		25	/* Not a typewriter */
+#define	ETXTBSY		26	/* Text file busy */
+#define	EFBIG		27	/* File too large */
+#define	ENOSPC		28	/* No space left on device */
+#define	ESPIPE		29	/* Illegal seek */
+#define	EROFS		30	/* Read-only file system */
+#define	EMLINK		31	/* Too many links */
+#define	EPIPE		32	/* Broken pipe */
+#define	EDOM		33	/* Math argument out of domain of func */
+#define	ERANGE		34	/* Math result not representable */
+
diff --git a/core/paging.c b/core/paging.c
index b83df2e..210d8b9 100644
--- a/core/paging.c
+++ b/core/paging.c
@@ -116,3 +116,19 @@ int pagingSetup(paddr_t upperKernelAddr)
 			"2:\n\t" ::"r"(cr3):"memory","eax");
 	return 0;
 }
+
+int pageMap(vaddr_t vaddr, paddr_t paddr, int flags)
+{
+	uint pdEntry = vaddr >> (PD_SHIFT);
+	uint ptEntry = (vaddr >> PT_SHIFT) & PTE_MASK;
+
+	// Thank to mirroring, we can access the PD
+	struct pde *pd = (struct pde *)(PD_MIRROR_PAGE_IDX * 4 * (1 << 20) +
+					PD_MIRROR_PAGE_IDX * 4 * (1 << 10));
+
+	struct pte *pt = (struct pte *)(PD_MIRROR_PAGE_IDX * 4 * (1 << 20) +
+					PD_MIRROR_PAGE_IDX * 4 * (1 << 10));
+
+	if(pd[pdEntry].present){
+	}
+}
diff --git a/core/paging.h b/core/paging.h
index 5daf35f..a5551f6 100644
--- a/core/paging.h
+++ b/core/paging.h
@@ -2,3 +2,5 @@
 #include "types.h"
 
 int pagingSetup(paddr_t upperKernelAddr);
+
+int pageMap(vaddr_t vaddr, paddr_t paddr, int flags);