From d8eaa13f2efc1eeca4e5f230d5a2d535aaf27338 Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Fri, 2 Jan 2026 00:47:16 +0800
Subject: dev(file-system): establish VFS and Read-only FAT32 File System

---
 include/kernel/buf.h      | 30 ++++++++++++++++++++++++++++++
 include/kernel/elf.h      | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 include/kernel/exec.h     |  6 ++++++
 include/kernel/mm.h       |  1 +
 include/kernel/proc_def.h |  6 ++++++
 5 files changed, 89 insertions(+)
 create mode 100644 include/kernel/buf.h
 create mode 100644 include/kernel/elf.h
 create mode 100644 include/kernel/exec.h

(limited to 'include/kernel')

diff --git a/include/kernel/buf.h b/include/kernel/buf.h
new file mode 100644
index 0000000..099523d
--- /dev/null
+++ b/include/kernel/buf.h
@@ -0,0 +1,30 @@
+#pragma once
+#include "common/types.h"
+#include "kernel/spinlock.h"
+
+#define BSIZE 1024
+#define NBUF 30
+
+struct Buf
+{
+    int valid;        // Whether the data has been read from the disk (1=valid, 0=invalid)
+    int disk;         // Whether it has been held by the driver (dirty bit/write-back flag is usually extended here)
+    uint32 dev;       // Device Number
+    uint32 blockno;   // Block number
+    uint32 refcnt;    // Reference Counting
+    struct Buf *prev; // LRU linked list
+    struct Buf *next;
+    uchar data[BSIZE];
+
+    Mutex lock; // Sleep Lock
+};
+
+namespace BufferCache
+{
+    void init();
+    struct Buf *bread(uint32 dev, uint32 blockno);
+    void bwrite(struct Buf *b);
+    void brelse(struct Buf *b);
+    void bpin(struct Buf *b);
+    void bunpin(struct Buf *b);
+} // namespace BufferCache
diff --git a/include/kernel/elf.h b/include/kernel/elf.h
new file mode 100644
index 0000000..c216f1c
--- /dev/null
+++ b/include/kernel/elf.h
@@ -0,0 +1,46 @@
+#pragma once
+#include "common/types.h"
+
+#define ELF_MAGIC 0x464C457F // "\x7FELF" in little endian
+
+// ELF File Header
+struct elfhdr
+{
+    uint32 magic; // Must equal ELF_MAGIC
+    uint8 elf[12];
+    uint16 type;
+    uint16 machine;
+    uint32 version;
+    uint64 entry; // Program Entry Point (Virtual Address)
+    uint64 phoff; // File offset of the Program Header Table
+    uint64 shoff;
+    uint32 flags;
+    uint16 ehsize;
+    uint16 phentsize;
+    uint16 phnum; // Number of Program Headers
+    uint16 shentsize;
+    uint16 shnum;
+    uint16 shstrndx;
+};
+
+// Program Header
+// Describes how to load segments from a file into memory
+struct proghdr
+{
+    uint32 type;
+    uint32 flags;
+    uint64 off;   // Offset of the section in the file
+    uint64 vaddr; // Virtual address of the segment in memory
+    uint64 paddr;
+    uint64 filesz; // Size of the section in the file
+    uint64 memsz;  // The size of the segment in memory (memsz >= filesz)
+    uint64 align;
+};
+
+// Values for Proghdr type
+#define ELF_PROG_LOAD 1
+
+// Flag bits for Proghdr flags
+#define ELF_PROG_FLAG_EXEC 1
+#define ELF_PROG_FLAG_WRITE 2
+#define ELF_PROG_FLAG_READ 4
\ No newline at end of file
diff --git a/include/kernel/exec.h b/include/kernel/exec.h
new file mode 100644
index 0000000..964e3bb
--- /dev/null
+++ b/include/kernel/exec.h
@@ -0,0 +1,6 @@
+#pragma once
+
+namespace Exec
+{
+    int exec(char *path, char **argv);
+}
\ No newline at end of file
diff --git a/include/kernel/mm.h b/include/kernel/mm.h
index 363ce74..1850574 100644
--- a/include/kernel/mm.h
+++ b/include/kernel/mm.h
@@ -18,6 +18,7 @@ namespace VM
 
     int copyout(uint64 *pagetable, uint64 dstva, char *src, uint64 len);
     int copyin(uint64 *pagetable, char *dst, uint64 srcva, uint64 len);
+    int copyinstr(uint64 *pagetable, char *dst, uint64 srcva, uint64 max);
 
     int handle_cow_fault(uint64 *pagetable, uint64 va);
     int mappages(uint64 *pagetable, uint64 va, uint64 size, uint64 pa, int perm);
diff --git a/include/kernel/proc_def.h b/include/kernel/proc_def.h
index e5a2cbc..06c80aa 100644
--- a/include/kernel/proc_def.h
+++ b/include/kernel/proc_def.h
@@ -1,8 +1,11 @@
 #pragma once
 #include "common/types.h"
+#include "common/fcntl.h"
 
 struct cpu;
 struct Trapframe;
+class Inode;
+struct file;
 
 enum ProcState
 {
@@ -51,6 +54,9 @@ struct Proc
     void *chan;
     int xstate;
 
+    Inode *cwd;
+    struct file *ofile[NOFILE];
+
     struct Proc *next;
     struct Proc *prev;
     int priority;
-- 
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