From 1767d390fbf3d0c65389de46caf0b6d43ef3b6ad Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Fri, 10 Jul 2026 11:24:56 +0800
Subject: feat: establish bootable new architecture checkpoint

Replace the compressed boot path with a relocatable higher-half RISC-V entry, expand memory and SMP support, and add the driver, TTY, VFS, exec, signal, syscall, initramfs, and self-test infrastructure needed for a bootable kernel checkpoint.
---
 na/fs/vfs_init.cc | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 na/fs/vfs_init.cc

(limited to 'na/fs/vfs_init.cc')

diff --git a/na/fs/vfs_init.cc b/na/fs/vfs_init.cc
new file mode 100644
index 0000000..ec56e88
--- /dev/null
+++ b/na/fs/vfs_init.cc
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+/*
+ * vfs_init.cc — Bootstrap the VFS: mount ramfs root, set global root
+ *
+ * Called from kernel_main() after slab_init() and ramfs_init().
+ * This is the moral equivalent of Linux's vfs_caches_init() +
+ * mnt_init() + init_rootfs().
+ */
+
+#include <lume/fs.h>
+#include <lume/dcache.h>
+#include <lume/file.h>
+#include <lume/mount.h>
+#include <lume/fdtable.h>
+#include <lume/fs_struct.h>
+#include <lume/klog.h>
+#include <lume/kprintf.h>
+#include <lume/task.h>
+#include <lume/sched.h>
+
+/* ================================================================== */
+/*  vfs_init — mount ramfs as root filesystem                         */
+/* ================================================================== */
+
+/*
+ * ramfs_mount is called internally via the file_system_type::mount
+ * callback registered by ramfs_init().  We look it up by name.
+ */
+extern file_system_type* get_fs_type(const char* name);
+extern super_block* alloc_super(file_system_type* type);
+
+void vfs_init()
+{
+    /* 1. Look up the ramfs filesystem type */
+    file_system_type* ramfs_type = get_fs_type("ramfs");
+    if (!ramfs_type || !ramfs_type->mount) {
+        printk(KERN_ERR "vfs_init: ramfs not registered!\n");
+        return;
+    }
+
+    /* 2. Mount ramfs */
+    super_block* sb = ramfs_type->mount(ramfs_type, 0, "ramfs", nullptr);
+    if (!sb || !sb->s_root) {
+        printk(KERN_ERR "vfs_init: failed to mount ramfs!\n");
+        return;
+    }
+
+    /* 3. Set global root */
+    g_root_dentry = sb->s_root;
+    g_root_mnt = nullptr;  /* TODO: allocate a proper vfsmount when mount.cc lands */
+
+    dget(g_root_dentry);  /* Hold a reference for the global root */
+
+    printk(KERN_INFO "[vfs] root filesystem mounted (ramfs)\n");
+
+    /* 4. Set up VFS state for the current (BSP idle) task,
+     *    which will be inherited by all subsequently created tasks. */
+    TaskControlBlock* bsp = current_task();
+    if (bsp) {
+        if (!bsp->files) {
+            bsp->files = alloc_files_struct();
+        }
+        if (!bsp->fs) {
+            bsp->fs = alloc_fs_struct();
+            if (bsp->fs) {
+                bsp->fs->root.de = g_root_dentry;
+                bsp->fs->root.mnt = g_root_mnt;
+                bsp->fs->pwd.de = g_root_dentry;
+                bsp->fs->pwd.mnt = g_root_mnt;
+                dget(g_root_dentry);  /* root ref */
+                dget(g_root_dentry);  /* pwd ref */
+            }
+        }
+        printk(KERN_INFO "[vfs] BSP task VFS context initialized\n");
+    }
+}
-- 
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