[vfs] Fix some things

core/mem.c

@@ -8,6 +8,13 @@
 extern uintptr_t end;
 uintptr_t placement_pointer = &end;
 
+void
+kmalloc_startat(
+		uintptr_t address
+		) {
+	placement_pointer = address;
+}
+
 /*
  * kmalloc() is the kernel's dumb placement allocator
  */

include/fs.h

@@ -9,6 +9,8 @@
 #define FS_SYMLINK     0x06
 #define FS_MOUNTPOINT  0x08
 
+struct fs_node;
+
 typedef uint32_t (*read_type_t)(struct fs_node*, uint32_t, uint32_t, uint8_t *);
 typedef uint32_t (*write_type_t)(struct fs_node*, uint32_t, uint32_t, uint8_t *);
 typedef void (*open_type_t)(struct fs_node*, uint8_t read, uint8_t write);
@@ -16,11 +18,6 @@ typedef void (*close_type_t)(struct fs_node*);
 typedef struct dirent * (*readdir_type_t)(struct fs_node*, uint32_t);
 typedef struct fs_node * (*finddir_type_t)(struct fs_node*, char *name);
 
-struct dirent {
-	char name[256];
-	uint32_t ino;
-};
-
 typedef struct fs_node {
 	char		name[256];
 	uint32_t	mask;
@@ -39,6 +36,12 @@ typedef struct fs_node {
 	struct fs_node	*ptr;
 } fs_node_t;
 
+struct dirent {
+	char name[256];
+	uint32_t ino;
+};
+
+
 extern fs_node_t *fs_root;
 
 uint32_t read_fs(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer);

include/system.h

@@ -86,6 +86,7 @@ extern void kprintf(const char *fmt, ...);
 
 /* Memory Management */
 extern uintptr_t placement_pointer;
+extern void kmalloc_startat(uintptr_t address);
 extern uintptr_t kmalloc_real(size_t size, int align, uintptr_t * phys);
 extern uintptr_t kmalloc(size_t size);
 extern uintptr_t kvmalloc(size_t size);

main.c

@@ -151,6 +151,9 @@ dump_multiboot(
  */
 int
 main(struct multiboot *mboot_ptr) {
+	if (mboot_ptr->mods_count > 0) {
+		kmalloc_startat(((uintptr_t *)mboot_ptr->mods_addr)[1]);
+	}
 	mboot_ptr = copy_multiboot(mboot_ptr);
 
 	gdt_install();	/* Global descriptor table */