paging is now enabled with __shaky__ code

kernel/arch/paging/paging.c

@@ -0,0 +1,55 @@
+#include <stdint.h>
+
+#include <stdio.h>
+
+#include <kernel/paging.h>
+
+//extern uint32_t endkernel; // found in link.ld
+
+/**
+ * The page table must be page aligned (aligned at 4KiB)
+ *
+ *
+ * This is a temporary solution, as we want a page frame allocator, to properly get page frames.. but this works for now
+ */
+uint32_t page_directory[PAGE_DIRECTORY_ENTRIES] __attribute__((aligned(4096)));
+
+uint32_t first_page_table[PAGE_TABLE_ENTRIES] __attribute__((aligned(4096)));
+
+void setup_page_table(void)
+{
+	uint32_t i;
+	for (i = 0; i < PAGE_TABLE_ENTRIES; i++) {
+		first_page_table[i] = (i * 0x1000) | 3; // supervisor, r/w, present
+	}
+	puts("test");
+}
+
+void setup_page_dir(void)
+{
+	setup_page_table();
+	/**
+	 * Now that we have a page directory, we need to blank it.
+	 *
+	 * The page directory should have exactly 1024 entries. We will set each entry to not present, so that the if the
+	 * MMU looks for that page table, it will see that it is not there yet.
+	 */
+	int i;
+	for (i = 0; i < PAGE_DIRECTORY_ENTRIES; i++) {
+		// This sets the following flags to the pages:
+		// 	Supervisor: Only kernel-mode can access them
+		// 	Write Enabled: It can be both read from and written to
+		// 	Not Present: The page table is not present
+		page_directory[i] = 0x00000002;
+	}
+
+	page_directory[0] = ((uint32_t) first_page_table) | 3;
+}
+
+void setup_paging(void)
+{
+	setup_page_dir();
+
+	load_page_directory(page_directory);
+	enable_paging();
+}

kernel/arch/paging/paging_src.s

@@ -0,0 +1,20 @@
+global load_page_directory
+load_page_directory:
+	push ebp
+	mov esp, ebp
+	mov eax, [esp + 4]
+	mov cr3, eax
+	mov esp, ebp
+	pop ebp
+	ret
+
+global enable_paging
+enable_paging:
+	push ebp
+	mov ebp, esp
+	mov eax, cr0
+	or eax, 0x80000000
+	mov cr0, eax
+	mov esp, ebp
+	pop ebp
+	ret