[VFS] Skeleton for moving victoria falls to rust.

rust/lib/client/denali_client/src/disk_reader.rs

@@ -0,0 +1,31 @@
+use mammoth::{cap::Capability, zion::ZError};
+
+use crate::{DenaliClient, DiskBlock, ReadRequest};
+
+pub struct DiskReader {
+    client: DenaliClient,
+    disk_id: u64,
+    lba_offset: u64,
+}
+
+impl DiskReader {
+    pub fn new(client: DenaliClient, disk_id: u64, lba_offset: u64) -> Self {
+        Self {
+            client,
+            disk_id,
+            lba_offset,
+        }
+    }
+
+    pub fn read(&mut self, lba: u64, cnt: u64) -> Result<Capability, ZError> {
+        let read_resp = self.client.read(&ReadRequest {
+            device_id: self.disk_id,
+            block: DiskBlock {
+                lba: self.lba_offset + lba,
+                size: cnt,
+            },
+        })?;
+
+        Ok(Capability::take(read_resp.memory))
+    }
+}

rust/lib/client/denali_client/src/lib.rs

@@ -3,3 +3,7 @@
 use core::include;
 
 include!(concat!(env!("OUT_DIR"), "/yunq.rs"));
+
+mod disk_reader;
+
+pub use disk_reader::DiskReader;

rust/lib/fs/ext2/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "ext2"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+denali_client = { path = "../../client/denali_client" }
+mammoth = { path = "../../mammoth" }

rust/lib/fs/ext2/src/ext2_driver.rs

@@ -0,0 +1,19 @@
+use denali_client::DiskReader;
+use mammoth::mem::MemoryRegion;
+
+use crate::types::Superblock;
+
+pub struct Ext2Driver {
+    reader: DiskReader,
+}
+
+impl Ext2Driver {
+    pub fn new(mut reader: DiskReader) -> Self {
+        let super_block_mem = MemoryRegion::from_cap(reader.read(2, 2).unwrap()).unwrap();
+        let super_block: &Superblock = super_block_mem.as_ref();
+        let inodes = super_block.inodes_count;
+        let magic = super_block.magic;
+        mammoth::debug!("Superblock ({:#x}): inodes: {:#x}", magic, inodes);
+        Self { reader }
+    }
+}

rust/lib/fs/ext2/src/lib.rs

@@ -0,0 +1,8 @@
+#![no_std]
+
+extern crate alloc;
+
+mod ext2_driver;
+mod types;
+
+pub use ext2_driver::Ext2Driver;

rust/lib/fs/ext2/src/types.rs

@@ -0,0 +1,30 @@
+#[repr(C, packed)]
+pub struct Superblock {
+    pub inodes_count: u32,
+    pub blocks_count: u32,
+    pub reserved_blocks_count: u32,
+    pub free_blocks_count: u32,
+    pub free_inodes_count: u32,
+    pub first_data_blok: u32,
+    pub log_block_size: u32,
+    pub log_frag_size: u32,
+    pub blocks_per_group: u32,
+    pub frags_per_group: u32,
+    pub inodes_per_group: u32,
+    pub mtime: u32,
+    pub wtime: u32,
+    pub mnt_count: u16,
+    pub max_mnt_count: u16,
+    pub magic: u16,
+    pub state: u16,
+    pub errors: u16,
+    pub minor_rev_level: u16,
+    pub lastcheck: u32,
+    pub checkinterval: u32,
+    pub creator_os: u32,
+    pub rev_level: u32,
+    pub def_resuid: u16,
+    pub def_resgid: u16,
+    pub first_ino: u32,
+    pub inode_size: u16,
+}

rust/lib/mammoth/src/mem.rs

@@ -103,6 +103,12 @@ impl MemoryRegion {
     }
 }
 
+impl<T> AsRef<T> for MemoryRegion {
+    fn as_ref(&self) -> &T {
+        unsafe { (self.virt_addr as *const T).as_ref().unwrap() }
+    }
+}
+
 impl Drop for MemoryRegion {
     fn drop(&mut self) {
         // FIXME: We shouldn't have to do this manual adjustment.