Improve filesystem (#24)

* Add doc about fs

* Add console on diskless boot

* Enumerate all disks

* Avoid hardcoded allocation of root dir

* Refactor ATA code

* Add BlockDevice

* Add mkfs command

* Update readme

* Add warning in the readme about disk modifications

* Use all bits inside BlockBitmap data

* Add makefile

* Overwrite only bootloader and kernel in disk image

* Update readme

* Add doc about mkfs

* Update mkfs command

Makefile

@@ -0,0 +1,33 @@
+.PHONY: setup image qemu
+.EXPORT_ALL_VARIABLES:
+
+setup:
+	curl https://sh.rustup.rs -sSf | sh
+	rustup install nightly
+	rustup default nightly
+	rustup component add rust-src
+	rustup component add llvm-tools-preview
+	cargo install cargo-xbuild bootimage
+
+output = vga
+keyboard = qwerty
+
+bin=target/x86_64-moros/release/bootimage-moros.bin
+img=disk.img
+
+$(img):
+	qemu-img create $(img) 32M
+
+# Rebuild MOROS if the features list changed
+image: $(img)
+	touch src/lib.rs
+	cargo bootimage --no-default-features --features $(output),$(keyboard) --release
+	dd conv=notrunc if=$(bin) of=$(img)
+
+opts = -cpu max -nic model=rtl8139 -hda $(img)
+ifeq ($(output),serial)
+	opts += -display none -serial stdio
+endif
+
+qemu:
+	qemu-system-x86_64 $(opts)

README.md

@@ -52,36 +52,26 @@ Install tools:
     rustup component add llvm-tools-preview
     cargo install cargo-xbuild bootimage
 
-Create disk:
-
-    qemu-img create disk.img 128M
-
 ## Usage
 
-QEMU with VGA Text Mode:
-
-    cargo xrun --release -- \
-      -cpu phenom \
-      -nic model=rtl8139 \
-      -hdc disk.img
+Build image:
 
-QEMU with a serial console:
+    make image output=vga keyboard=qwerty
 
-    cargo xrun --release --no-default-features --features serial,dvorak -- \
-      -cpu phenom \
-      -nic model=rtl8139 \
-      -serial stdio \
-      -display none \
-      -hdc disk.img
+Run on QEMU:
 
-Bochs instead of QEMU:
+    make qemu output=vga
 
-    sh run/bochs.sh
+Run on a native x86 computer:
 
-Or with `cool-retro-term` for a retro console look:
+    sudo dd if=target/x86_64-moros/release/bootimage-moros.bin of=/dev/sdx && sync
+    sudo reboot
 
-    sh run/cool-retro-term.sh
+MOROS will open a console in diskless mode after boot if no filesystem is
+detected. Use `mkfs` to create a filesystem on a disk.
 
+**Be careful not to overwrite the disk of your OS when using `dd` inside your OS
+or `mkfs` inside MOROS.**
 
 ## LICENSE
 

doc/filesystem.md

@@ -0,0 +1,71 @@
+# MOROS Filesystem
+
+## Disk
+
+A disk is separated in block of 512 bytes, grouped into three areas. The first
+is reserved for future uses, the second is used as a bitmap mapping the
+allocated blocks in the third area. The data stored on the disk use the blocks
+of the third area.
+
+During the first boot of the OS, the root dir will be allocated, using the
+first block of the data area.
+
+A location on the tree of dirs and files is named a path:
+
+  - The root dir is represented by a slash: `/`
+  - A dir inside the root will have its name appended to the slash: `/usr`
+  - Subsequent dirs will append a slash and their names: `/usr/admin`
+
+### Creation with QEMU
+
+    $ qemu-img create disk.img 128M
+    Formatting 'disk.img', fmt=raw size=134217728
+
+### Setup in diskless console
+
+During boot MOROS will detect the disks present on the ATA buses, then the
+filesystems on those disks. If no filesystem is found, MOROS will open a
+console in diskless mode to allow the user to create one with the `mkfs`
+command:
+
+    > mkfs /dev/ata/0/0
+
+## Data
+
+### BlockBitmap
+
+Bitmap of allocated blocks in the data area.
+
+### Block
+
+A block is small area of 512 bytes on a disk, and it is also part of linked
+list representing a file or a directory.
+
+The first 4 bytes of a block is the address of the next block on the list and
+the rest of block is the data stored in the block.
+
+### DirEntry
+
+A directory entry represent a file or a directory contained inside a directory.
+Each entry use a variable number of bytes that must fit inside the data of one
+block. Those bytes represent the kind of entry (file or dir), the address of
+the first block, the filesize (max 4GB), and the filename (max 255 chars) of
+the entry.
+
+Structure:
+
+  - 0..1: kind
+  - 1..5: addr
+  - 5..10: size
+  - 10..11: name len
+  - 11..n: name buf
+
+### Dir
+
+A directory contains the address of the first block where its directory entries
+are stored.
+
+### File
+
+A file contains the address of its first block along with its filesize and
+filename, and a reference to its parent directory.

doc/net.md → doc/network.md

@@ -1,4 +1,4 @@
-# MOROS Net
+# MOROS Network
 
 ## NET
 

run/bochs.sh

@@ -4,9 +4,6 @@ set -e
 
 dir=$(dirname "$0")
 
-# Build image if needed
-cd "$dir/.." && cargo bootimage --release
-
 # Clean up lock files that Bochs creates
 rm -f "$dir/../target/x86_64-moros/release/bootimage-moros.bin.lock"
 rm -f "$dir/../disk.img.lock"

run/cool-retro-term.sh

@@ -3,14 +3,10 @@
 set -e
 
 dir=$(dirname "$0")
-image="target/x86_64-moros/release/bootimage-moros.bin"
-qemu="qemu-system-x86_64 -display curses -cpu max -nic model=rtl8139 -hdc disk.img"
+qemu="qemu-system-x86_64 -display curses -cpu max -nic model=rtl8139 disk.img"
 #qemu="qemu-system-x86_64 -display curses -cpu max -hdc disk.img -netdev user,id=u1,hostfwd=tcp::2222-:22 -device rtl8139,netdev=u1 -object filter-dump,id=f1,netdev=u1,file=/tmp/qemu.pcap"
 
-# Build image if needed
-cd "$dir/.." && cargo bootimage --release
-
 echo "The MOROS theme at '$dir/cool-retro-term.json' have to be manually imported."
 
 # Launch qemu inside cool-retro-term
-cool-retro-term --fullscreen --profile "MOROS" --workdir "$dir/.." -e sh -c "$qemu $image 2>/dev/null"
+cool-retro-term --fullscreen --profile "MOROS" --workdir "$dir/.." -e sh -c "$qemu 2>/dev/null"

src/kernel/ata.rs

@@ -194,6 +194,8 @@ impl Bus {
     }
 
     pub fn read(&mut self, drive: u8, block: u32, buf: &mut [u8]) {
+        assert!(buf.len() == 512);
+
         self.setup(drive, block);
 
         self.write_command(Command::Read);
@@ -208,6 +210,8 @@ impl Bus {
     }
 
     pub fn write(&mut self, drive: u8, block: u32, buf: &[u8]) {
+        assert!(buf.len() == 512);
+
         self.setup(drive, block);
 
         self.write_command(Command::Write);
@@ -226,7 +230,7 @@ impl Bus {
 }
 
 lazy_static! {
-    pub static ref ATA_BUSES: Mutex<Vec<Bus>> = Mutex::new(Vec::new());
+    pub static ref BUSES: Mutex<Vec<Bus>> = Mutex::new(Vec::new());
 }
 
 fn disk_size(sectors: u32) -> (u32, String) {
@@ -239,74 +243,39 @@ fn disk_size(sectors: u32) -> (u32, String) {
 }
 
 pub fn init() {
-    let mut buses = ATA_BUSES.lock();
+    let mut buses = BUSES.lock();
     buses.push(Bus::new(0, 0x1F0, 0x3F6, 14));
     buses.push(Bus::new(1, 0x170, 0x376, 15));
 
-    let bus = 1;
-    let drive = 0;
-    if let Some(buf) = buses[bus].identify_drive(drive) {
-        let mut serial = String::new();
-        for i in 10..20 {
-            for &b in &buf[i].to_be_bytes() {
-                serial.push(b as char);
-            }
-        }
-        let mut model = String::new();
-        for i in 27..47 {
-            for &b in &buf[i].to_be_bytes() {
-                model.push(b as char);
+    for bus in 0..2 {
+        for drive in 0..2 {
+            if let Some(buf) = buses[bus].identify_drive(drive) {
+                let mut serial = String::new();
+                for i in 10..20 {
+                    for &b in &buf[i].to_be_bytes() {
+                        serial.push(b as char);
+                    }
+                }
+                let mut model = String::new();
+                for i in 27..47 {
+                    for &b in &buf[i].to_be_bytes() {
+                        model.push(b as char);
+                    }
+                }
+                let sectors = (buf[61] as u32) << 16 | (buf[60] as u32);
+                let (size, unit) = disk_size(sectors);
+                log!("ATA {}:{} {} {} ({} {})\n", bus, drive, model.trim(), serial.trim(), size, unit);
             }
         }
-        let sectors = (buf[61] as u32) << 16 | (buf[60] as u32);
-        let (size, unit) = disk_size(sectors);
-        log!("ATA {}:{} {} {} ({} {})\n", bus, drive, model.trim(), serial.trim(), size, unit);
-    }
-
-    /*
-    let block = 1;
-    let mut buf = [0u8; 512];
-    buses[1].read(drive, block, &mut buf);
-    for i in 0..256 {
-        if i % 8 == 0 {
-            print!("\n{:08X} ", i * 2);
-        }
-        print!("{:02X}{:02X} ", buf[i * 2], buf[i * 2 + 1]);
-    }
-    print!("\n");
-
-    buf[0x42] = 'H' as u8;
-    buf[0x43] = 'e' as u8;
-    buf[0x44] = 'l' as u8;
-    buf[0x45] = 'l' as u8;
-    buf[0x46] = 'o' as u8;
-    for i in 0..256 {
-        if i % 8 == 0 {
-            print!("\n{:08X} ", i * 2);
-        }
-        print!("{:02X}{:02X} ", buf[i * 2], buf[i * 2 + 1]);
-    }
-    print!("\n");
-    buses[1].write(drive, block, &mut buf);
-
-    let mut buf = [0u8; 512];
-    buses[1].read(drive, block, &mut buf);
-    for i in 0..256 {
-        if i % 8 == 0 {
-            print!("\n{:08X} ", i * 2);
-        }
-        print!("{:02X}{:02X} ", buf[i * 2], buf[i * 2 + 1]);
     }
-    print!("\n");
-    */
 }
 
 pub fn read(bus: u8, drive: u8, block: u32, mut buf: &mut [u8]) {
-    let mut buses = ATA_BUSES.lock();
+    let mut buses = BUSES.lock();
     buses[bus as usize].read(drive, block, &mut buf);
 }
 
 pub fn write(bus: u8, drive: u8, block: u32, buf: &[u8]) {
-    let mut buses = ATA_BUSES.lock();
+    let mut buses = BUSES.lock();
     buses[bus as usize].write(drive, block, &buf);
 }