diff --git a/libconfig/src/bootgen.rs b/libconfig/src/bootgen.rs
index 004e1d9..d4ca3b0 100644
--- a/libconfig/src/bootgen.rs
+++ b/libconfig/src/bootgen.rs
@@ -1,9 +1,12 @@
 use alloc::vec::Vec;
-use crate::sd_reader::Error
-use fatfs::io::{Read, Seek, SeekFrom};
+use fatfs::{self, IoBase, Read, Seek, SeekFrom};
 use libboard_zynq::devc;
+use crate::sd_reader;
+use crate::File;
 use log::debug;
 
+type Error = fatfs::Error<sd_reader::Error>;
+
 #[derive(Debug)]
 pub enum BootgenLoadingError {
     InvalidBootImageHeader,
@@ -13,8 +16,8 @@ pub enum BootgenLoadingError {
     DevcError(devc::DevcError),
 }
 
-impl From<sd_reader::Error> for BootgenLoadingError {
-    fn from(error: sd_reader::Error) -> Self {
+impl From<Error> for BootgenLoadingError {
+    fn from(error: Error) -> Self {
         BootgenLoadingError::IoError(error)
     }
 }
@@ -59,7 +62,7 @@ struct PartitionHeader {
 }
 
 /// Read a u32 word from the reader.
-fn read_u32<Reader: Read>(reader: &mut Reader) -> Result<u32, BootgenLoadingError> {
+fn read_u32<'a>(reader: &mut File<'a>) -> Result<u32, BootgenLoadingError> {
     let mut buffer: [u8; 4] = [0; 4];
     reader.read_exact(&mut buffer)?;
     let mut result: u32 = 0;
@@ -70,8 +73,8 @@ fn read_u32<Reader: Read>(reader: &mut Reader) -> Result<u32, BootgenLoadingErro
 }
 
 /// Load PL partition header.
-fn load_pl_header<File: Read + Seek>(
-    file: &mut File,
+fn load_pl_header<'a>(
+    file: &mut File<'a>,
 ) -> Result<Option<PartitionHeader>, BootgenLoadingError> {
     let mut buffer: [u8; 0x40] = [0; 0x40];
     file.read_exact(&mut buffer)?;
@@ -83,8 +86,8 @@ fn load_pl_header<File: Read + Seek>(
     }
 }
 
-fn load_ps_header<File: Read + Seek>(
-    file: &mut File,
+fn load_ps_header<'a>(
+    file: &mut File<'a>,
 ) -> Result<Option<PartitionHeader>, BootgenLoadingError> {
     let mut buffer: [u8; 0x40] = [0; 0x40];
     file.read_exact(&mut buffer)?;
@@ -99,10 +102,10 @@ fn load_ps_header<File: Read + Seek>(
 /// Locate the partition from the image, and return the size (in bytes) of the partition if successful.
 /// This function would seek the file to the location of the partition.
 fn locate<
-    File: Read + Seek,
-    F: Fn(&mut File) -> Result<Option<PartitionHeader>, BootgenLoadingError>,
+    'a,
+    F: Fn(&mut File<'a>) -> Result<Option<PartitionHeader>, BootgenLoadingError>,
 >(
-    file: &mut File,
+    file: &mut File<'a>,
     f: F,
 ) -> Result<usize, BootgenLoadingError> {
     file.seek(SeekFrom::Start(0))?;
@@ -150,7 +153,7 @@ fn locate<
 /// Load bitstream from bootgen file.
 /// This function parses the file, locate the bitstream and load it through the PCAP driver.
 /// It requires a large buffer, please enable the DDR RAM before using it.
-pub fn load_bitstream<File: Read + Seek>(file: &mut File) -> Result<(), BootgenLoadingError> {
+pub fn load_bitstream<'a>(file: &mut File<'a>) -> Result<(), BootgenLoadingError> {
     let size = locate(file, load_pl_header)?;
     unsafe {
         // align to 64 bytes
@@ -171,7 +174,7 @@ pub fn load_bitstream<File: Read + Seek>(file: &mut File) -> Result<(), BootgenL
     }
 }
 
-pub fn get_runtime<File: Read + Seek>(file: &mut File) -> Result<Vec<u8>, BootgenLoadingError> {
+pub fn get_runtime<'a>(file: &mut File<'a>) -> Result<Vec<u8>, BootgenLoadingError> {
     let size = locate(file, load_ps_header)?;
     let mut buffer = Vec::with_capacity(size);
     unsafe {
diff --git a/libconfig/src/lib.rs b/libconfig/src/lib.rs
index 8aaf9dd..970c1a3 100644
--- a/libconfig/src/lib.rs
+++ b/libconfig/src/lib.rs
@@ -1,19 +1,24 @@
 #![no_std]
 extern crate alloc;
 
+use alloc::{rc::Rc, string::FromUtf8Error, string::String, vec::Vec};
+use sd_reader::SdReader;
 use core::fmt;
-use alloc::{string::FromUtf8Error, string::String, vec::Vec, rc::Rc};
-use fatfs::io::{Read, Write, Seek, SeekFrom}
+use fatfs::{self, IoBase, Read, Seek, SeekFrom, Write};
 use libboard_zynq::sdio;
 
-pub mod sd_reader;
-pub mod net_settings;
 pub mod bootgen;
+pub mod net_settings;
+pub mod sd_reader;
+
+type SdReadError = fatfs::Error<sd_reader::Error>;
+
+pub type File<'a> = fatfs::File<'a, SdReader, fatfs::NullTimeProvider, fatfs::LossyOemCpConverter>;
 
 #[derive(Debug)]
 pub enum Error<'a> {
     SdError(sdio::sd_card::CardInitializationError),
-    IoError(sd_reader::Error),
+    IoError(SdReadError),
     Utf8Error(FromUtf8Error),
     KeyNotFoundError(&'a str),
     NoConfig,
@@ -39,8 +44,8 @@ impl<'a> From<sdio::sd_card::CardInitializationError> for Error<'a> {
     }
 }
 
-impl<'a> From<sd_reader::Error> for Error<'a> {
-    fn from(error: sd_reader::Error) -> Self {
+impl<'a> From<SdReadError> for Error<'a> {
+    fn from(error: SdReadError) -> Self {
         Error::IoError(error)
     }
 }
@@ -51,14 +56,31 @@ impl<'a> From<FromUtf8Error> for Error<'a> {
     }
 }
 
+fn read_to_string<'a>(file: &mut File<'a>, read_str: &mut String) -> Result<'a, ()> {
+    let mut buffer = Vec::new();
+    let mut temp_buffer = [0; 500];
+    loop {
+        let read_bytes = file.read(&mut temp_buffer)?;
+        if read_bytes != buffer.len() { 
+            buffer.extend_from_slice(&temp_buffer[..read_bytes]);
+            break; 
+        }
+        else { 
+            buffer.extend_from_slice(&temp_buffer); 
+        }
+    }
+    read_str.extend(String::from_utf8(buffer));
+    Ok(())
+}
+
 fn parse_config<'a>(
     key: &'a str,
     buffer: &mut Vec<u8>,
-    file: fatfs::File<sd_reader::SdReader>,
+    mut file: File<'a>,
 ) -> Result<'a, ()> {
     let prefix = [key, "="].concat().to_ascii_lowercase();
     let mut read_buffer = String::new();
-    file.read_to_string(&mut read_buffer);
+    read_to_string(&mut file, &mut read_buffer)?;
     for line in read_buffer.lines() {
         let line = line.to_ascii_lowercase();
         if line.starts_with(&prefix) {
@@ -85,7 +107,9 @@ impl Config {
         let reader = sd_reader::SdReader::new(sd);
 
         let fs = reader.mount_fatfs(sd_reader::PartitionEntry::Entry1)?;
-        Ok(Config { fs: Some(Rc::new(fs)) })
+        Ok(Config {
+            fs: Some(Rc::new(fs)),
+        })
     }
 
     pub fn from_fs(fs: Option<Rc<fatfs::FileSystem<sd_reader::SdReader>>>) -> Self {
@@ -96,12 +120,12 @@ impl Config {
         Config { fs: None }
     }
 
-    pub fn read<'b>(&self, key: &'b str) -> Result<'b, Vec<u8>> {
+    pub fn read<'b>(&'b self, key: &'b str) -> Result<'b, Vec<u8>> {
         if let Some(fs) = &self.fs {
             let root_dir = fs.root_dir();
             let mut buffer: Vec<u8> = Vec::new();
             match root_dir.open_file(&["/CONFIG/", key, ".BIN"].concat()) {
-                Ok(mut f) => f.read_to_end(&mut buffer).map(|_| ())?,
+                Ok(mut f) => f.read(&mut buffer).map(|_| ())?,
                 Err(_) => match root_dir.open_file("/CONFIG.TXT") {
                     Ok(f) => parse_config(key, &mut buffer, f)?,
                     Err(_) => return Err(Error::KeyNotFoundError(key)),
@@ -113,11 +137,11 @@ impl Config {
         }
     }
 
-    pub fn read_str<'b>(&self, key: &'b str) -> Result<'b, String> {
+    pub fn read_str<'b>(&'b self, key: &'b str) -> Result<'b, String> {
         Ok(String::from_utf8(self.read(key)?)?)
     }
 
-    pub fn remove<'b>(&self, key: &'b str) -> Result<'b, ()> {
+    pub fn remove<'b>(&'b self, key: &'b str) -> Result<'b, ()> {
         if let Some(fs) = &self.fs {
             let root_dir = fs.root_dir();
             match root_dir.remove(&["/CONFIG/", key, ".BIN"].concat()) {
@@ -127,18 +151,19 @@ impl Config {
                     match root_dir.create_file("/CONFIG.TXT") {
                         Ok(mut f) => {
                             let mut buffer = String::new();
-                            f.read_to_string(&mut buffer)?;
+                            read_to_string(&mut f, &mut buffer)?;
                             f.seek(SeekFrom::Start(0))?;
                             f.truncate()?;
                             for line in buffer.lines() {
-                                if line.len() > 0 && !line.to_ascii_lowercase().starts_with(&prefix) {
+                                if line.len() > 0 && !line.to_ascii_lowercase().starts_with(&prefix)
+                                {
                                     f.write(line.as_bytes())?;
                                     f.write(NEWLINE)?;
                                 }
                             }
                             Ok(())
-                        },
-                        Err(_) => Err(Error::KeyNotFoundError(key))
+                        }
+                        Err(_) => Err(Error::KeyNotFoundError(key)),
                     }
                 }
             }
@@ -164,7 +189,10 @@ impl Config {
             if is_str {
                 let mut f = root_dir.create_file("/CONFIG.TXT")?;
                 f.seek(SeekFrom::End(0))?;
-                write!(f, "{}={}\n", key, String::from_utf8(value).unwrap())?;
+                f.write(key.as_bytes());
+                f.write("=".as_bytes());
+                f.write(value.as_slice());
+                f.write(NEWLINE);
             } else {
                 let dir = root_dir.create_dir("/CONFIG")?;
                 let mut f = dir.create_file(&[key, ".BIN"].concat())?;
diff --git a/libconfig/src/sd_reader.rs b/libconfig/src/sd_reader.rs
index c1da67b..6a11ea9 100644
--- a/libconfig/src/sd_reader.rs
+++ b/libconfig/src/sd_reader.rs
@@ -1,9 +1,8 @@
-use fatfs;
-use fatfs::io::{Read, Seek, SeekFrom, Write}
-use libboard_zynq::sdio::{sd_card::SdCard, CmdTransferError};
-use log::debug;
 use alloc::vec::Vec;
 use core::fmt;
+use fatfs::{self, IoBase, IoError, Read, Seek, SeekFrom, Write};
+use libboard_zynq::sdio::{sd_card::SdCard, CmdTransferError};
+use log::debug;
 
 const MBR_SIGNATURE: [u8; 2] = [0x55, 0xAA];
 const PARTID_FAT12: u8 = 0x01;
@@ -17,24 +16,24 @@ const BLOCK_SIZE: usize = 512;
 
 #[derive(Debug)]
 pub struct Error {
-    message: String
+    message: &'static str,
 }
 
 impl Error {
-    pub fn new(message: &str) -> Self {
-        Self { message: String::new(message) }
+    pub fn new(message: &'static str) -> Self {
+        Self { message: message }
     }
 }
 
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, self.message)
+        write!(f, "{}", self.message)
     }
 }
 
 impl IoError for Error {
     fn is_interrupted(&self) -> bool {
-        false            
+        false
     }
 
     fn new_unexpected_eof_error() -> Self {
@@ -110,7 +109,7 @@ impl SdReader {
 
     /// Internal read function for unaligned read.
     /// The read must not cross block boundary.
-    fn read_unaligned(&mut self, buf: &mut [u8]) -> Result<usize> {
+    fn read_unaligned(&mut self, buf: &mut [u8]) -> Result<usize, Error> {
         if buf.len() == 0 {
             return Ok(0);
         }
@@ -124,7 +123,7 @@ impl SdReader {
 
     /// Internal write function for unaligned write.
     /// The write must not cross block boundary.
-    fn write_unaligned(&mut self, buf: &[u8]) -> Result<usize> {
+    fn write_unaligned(&mut self, buf: &[u8]) -> Result<usize, Error> {
         if buf.len() == 0 {
             return Ok(0);
         }
@@ -175,7 +174,7 @@ impl SdReader {
     }
 
     /// Set the base offset of the SD card, to transform from physical address to logical address.
-    fn set_base_offset(&mut self, offset: u32) -> Result<u64> {
+    fn set_base_offset(&mut self, offset: u32) -> Result<u64, Error> {
         self.offset = offset;
         self.seek(SeekFrom::Start(0))
     }
@@ -183,27 +182,28 @@ impl SdReader {
     /// Mount fatfs from partition entry, and return the fatfs object if success.
     /// This takes the ownership of self, so currently there is no way to recover from an error,
     /// except creating a new SD card instance.
-    pub fn mount_fatfs(mut self, entry: PartitionEntry) -> Result<fatfs::FileSystem<Self>> {
+    pub fn mount_fatfs(
+        mut self,
+        entry: PartitionEntry,
+    ) -> Result<fatfs::FileSystem<Self>, fatfs::Error<Error>> {
         let mut buffer: [u8; 4] = [0; 4];
         self.seek(SeekFrom::Start(0x1FE))?;
         self.read_exact(&mut buffer[..2])?;
         // check MBR signature
         if buffer[..2] != MBR_SIGNATURE {
-            return Err(Error::new(
-                "Incorrect signature for MBR sector.",
-            ));
+            return Err(fatfs::Error::Io(Error::new("Incorrect signature for MBR sector.")));
         }
         // Read partition ID.
         self.seek(SeekFrom::Start(entry as u64 + 0x4))?;
         self.read_exact(&mut buffer[..1])?;
         debug!("Partition ID: {:0X}", buffer[0]);
         match buffer[0] {
-            PARTID_FAT12 | PARTID_FAT16_LESS32M | PARTID_FAT16 |
-            PARTID_FAT16_LBA | PARTID_FAT32 | PARTID_FAT32_LBA => {}
+            PARTID_FAT12 | PARTID_FAT16_LESS32M | PARTID_FAT16 | PARTID_FAT16_LBA
+            | PARTID_FAT32 | PARTID_FAT32_LBA => {}
             _ => {
-                return Err(Error::new(
+                return Err(fatfs::Error::Io(Error::new(
                     "No FAT partition found for the specified entry.",
-                ));
+                )));
             }
         }
         // Read LBA
@@ -219,6 +219,25 @@ impl SdReader {
         // setup fatfs
         fatfs::FileSystem::new(self, fatfs::FsOptions::new())
     }
+
+    fn fill_buf(&mut self) -> Result<&[u8], Error> {
+        if self.index == BLOCK_SIZE {
+            // flush the buffer if it is dirty before overwriting it with new data
+            if self.dirty {
+                self.flush()?;
+            }
+            // reload buffer
+            self.sd
+                .read_block(self.byte_addr / (BLOCK_SIZE as u32), 1, &mut self.buffer)?;
+            self.index = (self.byte_addr as usize) % BLOCK_SIZE;
+        }
+        Ok(&self.buffer[self.index..])
+    }
+
+    fn consume(&mut self, amt: usize) {
+        self.index += amt;
+        self.byte_addr += amt as u32;
+    }
 }
 
 impl Read for SdReader {
@@ -272,8 +291,7 @@ impl Write for SdReader {
     fn flush(&mut self) -> Result<(), Error> {
         if self.dirty {
             let block_addr = (self.byte_addr - self.index as u32) / (BLOCK_SIZE as u32);
-            self.sd
-                .write_block(block_addr, 1, &self.buffer)?;
+            self.sd.write_block(block_addr, 1, &self.buffer)?;
             self.dirty = false;
         }
         Ok(())
diff --git a/szl/src/main.rs b/szl/src/main.rs
index 82dee7a..cc19d1e 100644
--- a/szl/src/main.rs
+++ b/szl/src/main.rs
@@ -8,7 +8,7 @@ mod netboot;
 
 use alloc::rc::Rc;
 use core::mem;
-use fatfs::io::{Read, Seek};
+use fatfs::{self, DefaultTimeProvider, LossyOemCpConverter, Read, Seek};
 use libboard_zynq::{
     self as zynq,
     clocks::source::{ArmPll, ClockSource, IoPll},
@@ -16,7 +16,7 @@ use libboard_zynq::{
     logger, println, sdio, slcr,
     timer::GlobalTimer,
 };
-use libconfig::{bootgen, sd_reader, Config};
+use libconfig::{bootgen, sd_reader, Config, File};
 use libcortex_a9::{
     asm::{dsb, isb},
     cache::{bpiall, dcciall, iciallu},
@@ -30,8 +30,8 @@ extern "C" {
     static mut __runtime_end: usize;
 }
 
-fn boot_sd<File: Read + Seek>(
-    file: &mut Option<File>,
+fn boot_sd<'a>(
+    file: &mut Option<File<'a>>,
     runtime_start: *mut u8,
     runtime_max: usize,
 ) -> Result<(), ()> {
diff --git a/szl/src/netboot.rs b/szl/src/netboot.rs
index 770c270..26e9413 100644
--- a/szl/src/netboot.rs
+++ b/szl/src/netboot.rs
@@ -1,7 +1,7 @@
 use alloc::vec;
 use alloc::vec::Vec;
 use byteorder::{ByteOrder, NetworkEndian};
-use fatfs::io::{Read, Seek};
+use fatfs::{Read, Seek};
 use libboard_zynq::{
     devc,
     eth::Eth,
@@ -13,7 +13,7 @@ use libboard_zynq::{
     },
     timer::GlobalTimer,
 };
-use libconfig::{bootgen, net_settings, Config};
+use libconfig::{bootgen, net_settings, Config, File};
 
 enum NetConnState {
     WaitCommand,
@@ -48,7 +48,7 @@ impl NetConn {
         self.gateware_downloaded = false;
     }
 
-    fn input_partial<File: Read + Seek>(
+    fn input_partial(
         &mut self,
         bootgen_file: &mut Option<File>,
         runtime_start: *mut u8,
@@ -284,9 +284,9 @@ impl NetConn {
         }
     }
 
-    fn input<File: Read + Seek>(
+    fn input<'a>(
         &mut self,
-        bootgen_file: &mut Option<File>,
+        bootgen_file: &mut Option<File<'a>>,
         runtime_start: *mut u8,
         runtime_max_len: usize,
         buf: &[u8],
@@ -309,8 +309,8 @@ impl NetConn {
     }
 }
 
-pub fn netboot<File: Read + Seek>(
-    bootgen_file: &mut Option<File>,
+pub fn netboot<'a>(
+    bootgen_file: &mut Option<File<'a>>,
     cfg: Config,
     runtime_start: *mut u8,
     runtime_max_len: usize,