Implement fat16 read + file read

src/fs/fat/fat16.rs

@@ -285,7 +285,7 @@ impl Fat16 {
         Ok(cluster_to_use)
     }
 
-    fn read_internal_recursively<T : Sized>(
+    fn read_internal_recursively<T: Sized>(
         &mut self,
         cluster: u16,
         offset: usize,
@@ -488,8 +488,13 @@ impl FileSystem for Fat16 {
         unimplemented!()
     }
 
-    fn fread(&mut self, out: &mut [u16], size: u32, nmemb: u32, fd: usize) -> Result<u32, ErrorCode> {
-
+    fn fread(
+        &mut self,
+        out: &mut [u16],
+        size: u32,
+        nmemb: u32,
+        fd: usize,
+    ) -> Result<u32, ErrorCode> {
         let fat_desc = self.fds.get(fd).ok_or(ErrorCode::InvArg)?;
         let item_binding = Arc::clone(&fat_desc.item);
         let item = match &*item_binding {
@@ -500,7 +505,12 @@ impl FileSystem for Fat16 {
         let offset = fat_desc.pos;
 
         for _ in 0..nmemb {
-            self.read_internal(item.first_cluster(), offset.try_into()?, size.try_into()?, out)?;
+            self.read_internal(
+                item.first_cluster(),
+                offset.try_into()?,
+                size.try_into()?,
+                out,
+            )?;
         }
         Ok(nmemb)
     }

src/fs/file.rs

@@ -47,8 +47,12 @@ pub struct FileDescriptor {
 impl FileDescriptor {
     pub fn new(disk: Arc<Mutex<Disk>>) -> Result<Arc<Self>, ErrorCode> {
         let mut descriptors = FILE_DESCRIPTORS.write();
-
-        if let Some((i, slot)) = descriptors.iter_mut().enumerate().find(|(_, d)| d.is_none()) {
+
+        if let Some((i, slot)) = descriptors
+            .iter_mut()
+            .enumerate()
+            .find(|(_, d)| d.is_none())
+        {
             let fd = Arc::new(Self {
                 index: i + 1,
                 disk: Arc::clone(&disk),
@@ -80,7 +84,12 @@ fn file_get_mode_by_string(mode_str: &str) -> FileMode {
     }
 }
 
-pub fn fread(out: &mut [u16], size: u32, nmemb: u32, fd: FileDescriptorIndex) -> Result<(), ErrorCode> {
+pub fn fread(
+    out: &mut [u16],
+    size: u32,
+    nmemb: u32,
+    fd: FileDescriptorIndex,
+) -> Result<(), ErrorCode> {
     if size == 0 || nmemb == 0 || fd < 1 {
         return Err(ErrorCode::InvArg);
     }
@@ -91,7 +100,7 @@ pub fn fread(out: &mut [u16], size: u32, nmemb: u32, fd: FileDescriptorIndex) ->
         let mut disk = desc.disk.lock();
         match &mut disk.fs {
             None => return Err(ErrorCode::NoFs),
-            Some(fs) => fs.fread(out, size, nmemb, fd)?
+            Some(fs) => fs.fread(out, size, nmemb, fd)?,
         };
     }
     Ok(())

src/fs/mod.rs

@@ -21,7 +21,13 @@ pub trait FileSystem: Send + Sync {
         mode: FileMode,
     ) -> Result<(), ErrorCode>;
     fn fseek(&self, fd: usize, offset: usize, whence: FileSeekMode) -> Result<(), ErrorCode>;
-    fn fread(&mut self, out: &mut [u16], size: u32, nmemb: u32, fd: usize) -> Result<u32, ErrorCode>;
+    fn fread(
+        &mut self,
+        out: &mut [u16],
+        size: u32,
+        nmemb: u32,
+        fd: usize,
+    ) -> Result<u32, ErrorCode>;
     fn fstat(&self, fd: usize, stat: FileStat) -> Result<(), ErrorCode>;
     fn fclose(&self, fd: usize) -> Result<(), ErrorCode>;
     fn fs_resolve(disk: &Disk) -> Result<Self, ErrorCode>

src/kernel.rs

@@ -59,9 +59,9 @@ use crate::memory::paging::PageAddress;
 use crate::memory::paging::PageDirectoryEntry;
 use crate::memory::paging::Paging256TBChunk;
 use alloc::boxed::Box;
-use fs::file::fread;
 use core::panic::PanicInfo;
 use fs::file::fopen;
+use fs::file::fread;
 use idt::IDT;
 
 #[panic_handler]
@@ -165,7 +165,6 @@ pub extern "C" fn kernel_main() -> ! {
     let mut buf = [0; 8];
     fread(&mut buf, 8, 1, fd).expect("Failed to read HELLO.TXT");
     println!("We read 1:/HELLO.TXT: \"{:?}\"", buf);
-
 
     println!("Testing a kernel panic using Rust's unimplemented! macro.");