add lab answers

labcodes_answer/lab5_result/kern/fs/fs.h

@@ -0,0 +1,12 @@
+#ifndef __KERN_FS_FS_H__
+#define __KERN_FS_FS_H__
+
+#include <mmu.h>
+
+#define SECTSIZE            512
+#define PAGE_NSECT          (PGSIZE / SECTSIZE)
+
+#define SWAP_DEV_NO         1
+
+#endif /* !__KERN_FS_FS_H__ */
+

labcodes_answer/lab5_result/kern/fs/swapfs.c

@@ -0,0 +1,27 @@
+#include <swap.h>
+#include <swapfs.h>
+#include <mmu.h>
+#include <fs.h>
+#include <ide.h>
+#include <pmm.h>
+#include <assert.h>
+
+void
+swapfs_init(void) {
+    static_assert((PGSIZE % SECTSIZE) == 0);
+    if (!ide_device_valid(SWAP_DEV_NO)) {
+        panic("swap fs isn't available.\n");
+    }
+    max_swap_offset = ide_device_size(SWAP_DEV_NO) / (PGSIZE / SECTSIZE);
+}
+
+int
+swapfs_read(swap_entry_t entry, struct Page *page) {
+    return ide_read_secs(SWAP_DEV_NO, swap_offset(entry) * PAGE_NSECT, page2kva(page), PAGE_NSECT);
+}
+
+int
+swapfs_write(swap_entry_t entry, struct Page *page) {
+    return ide_write_secs(SWAP_DEV_NO, swap_offset(entry) * PAGE_NSECT, page2kva(page), PAGE_NSECT);
+}
+

labcodes_answer/lab5_result/kern/fs/swapfs.h

@@ -0,0 +1,12 @@
+#ifndef __KERN_FS_SWAPFS_H__
+#define __KERN_FS_SWAPFS_H__
+
+#include <memlayout.h>
+#include <swap.h>
+
+void swapfs_init(void);
+int swapfs_read(swap_entry_t entry, struct Page *page);
+int swapfs_write(swap_entry_t entry, struct Page *page);
+
+#endif /* !__KERN_FS_SWAPFS_H__ */
+