Merge pull request 'feature/nikocs/framebuffer' (#1) from feature/nikocs/framebuffer into develop

Reviewed-on: #1

.cargo/config

@@ -8,5 +8,5 @@ rustflags = [
 
 [tarcet.riscv32i-unknown-none-elf]
 rustflags = [
-    "-C", "link-args=-nostdlib -ffreestanding -fPIC",
+    "-C", "link-args=-nostdlib -ffreestanding -relocation-model=static",
 ]

Cargo.toml

@@ -24,7 +24,7 @@ panic = "abort"
 opt-level = "z"
 debug-assertions = false
 overflow-checks = false
-strip = false
+strip = true
 lto = true
 codegen-units = 1
 
@@ -34,8 +34,9 @@ cc = "1.0"
 [features]
 default = []
 debug_messages = []
-arch_virt = ["dev_virtio", "fs_fat32", "liblbos/arch_riscv32", "ddi/arch_riscv32"]
+arch_virt = ["dev_virtio", "dev_framebuffer", "fs_fat32", "liblbos/arch_riscv32", "ddi/arch_riscv32"]
 arch_ofw = []
 arch_ppc32 = ["compiler_builtins", "arch_ofw", "fs_fat32"]
 dev_virtio = []
+dev_framebuffer = []
 fs_fat32 = []

liblbos/src/syscalls.rs

@@ -67,6 +67,19 @@ pub enum SysCall {
     WaitForNotifAck = 13,
     /// returns the environment pointer for the given task
     EnvironmentPointer = 14,
+    /// disables the kernel framebuffer console, allowing you to use it for other purposes.
+    /// if there is no device providing a gpu, this will not do anything.
+    DisableFramebufferConsole = 15,
+    /// enables the kernel framebuffer console, this will result in an immediate framebuffer console reset.
+    /// if the framebuffer console is already enabled, then it will be reset upon calling this.
+    /// if there is no device providing a gpu, this will not do anything.
+    EnableFramebufferConsole = 16,
+    /// gets a pointer to the framebuffer
+    /// if there is no device providing a gpu, this will return a null pointer
+    FramebufferPointer = 17,
+    /// flushes changes done within the given rectangle to the framebuffer
+    /// if there is no device providing a gpu, this will not do anything
+    FlushFramebufferRect = 18,
 
     /// initializes kernel, ONLY CALL ONCE! IN FACT, YOU PROBABLY NEVER NEED TO CALL THIS
     InitKernel = 666
@@ -93,6 +106,10 @@ pub fn usize2sc(u: usize) -> SysCall {
         12 => SysCall::PendingNotifications,
         13 => SysCall::WaitForNotifAck,
         14 => SysCall::EnvironmentPointer,
+        15 => SysCall::DisableFramebufferConsole,
+        16 => SysCall::EnableFramebufferConsole,
+        17 => SysCall::FramebufferPointer,
+        18 => SysCall::FlushFramebufferRect,
         666 => SysCall::InitKernel,
         _ => SysCall::NoAction,
     }
@@ -166,6 +183,22 @@ pub fn environment_pointer() -> usize {
     syscall(SysCall::EnvironmentPointer, 0, 0, 0, 0, 0, 0)
 }
 
+pub fn disable_framebuffer_console() {
+    syscall(SysCall::DisableFramebufferConsole, 0, 0, 0, 0, 0, 0);
+}
+
+pub fn enable_framebuffer_console() {
+    syscall(SysCall::EnableFramebufferConsole, 0, 0, 0, 0, 0, 0);
+}
+
+pub fn framebuffer_pointer() -> usize {
+    syscall(SysCall::FramebufferPointer, 0, 0, 0, 0, 0, 0)
+}
+
+pub fn flush_framebuffer_rect(x: usize, y: usize, w: usize, h: usize) {
+    syscall(SysCall::FlushFramebufferRect, x, y, w, h, 0, 0);
+}
+
 pub fn init_kernel() {
     syscall(SysCall::InitKernel, 0, 0, 0, 0, 0, 0);
 }

qemurun.sh

@@ -1,2 +1,5 @@
 #!/usr/bin/env bash
-qemu-system-riscv32 -machine virt -bios none -display gtk -drive if=none,format=raw,file=/dev/loop0,id=disk1 -device virtio-blk-device,drive=disk1 -serial mon:stdio -d guest_errors,unimp -m 5M -kernel target/riscv32imac-unknown-none-elf/release/lbos
+
+storage_device="${1}"
+
+qemu-system-riscv32 -machine virt -bios none -drive if=none,format=raw,file="${storage_device}",id=disk1 -device virtio-blk-device,drive=disk1 -display sdl -device virtio-gpu-device -serial stdio -m 10M -device loader,cpu-num=0,file=target/riscv32imac-unknown-none-elf/release/lbos -monitor telnet:127.0.0.1:1235,server,nowait -d guest_errors,unimp

src/arch/ofw/ofw_framebuffer/mod.rs

@@ -1,3 +1,5 @@
+// fixme: port this to the device-agnostic framebuffer console
+
 pub mod colors;
 pub mod extrachars;
 pub mod terminal;

src/arch/virt/asm/linker.ld

@@ -4,8 +4,13 @@ ENTRY( _start )
 
 MEMORY
 {
-    rom (wxa) : ORIGIN = 0x80000000, LENGTH = 64 * 1024
+    rom (wxa) : ORIGIN = 0x80000000, LENGTH = 0x10000
-    ram (wxa) : ORIGIN = 0x80010000, LENGTH = 1048510
+
+    ram (wxa) : ORIGIN = 0x80010000, LENGTH = 0x10000
+
+    virtqueues (wxa) : ORIGIN = 0x80020000, LENGTH = 0x20000
+
+    framebuffer (wxa) : ORIGIN = 0x80040000, LENGTH = 320 * 240 * 4
 }
 
 PHDRS
@@ -36,7 +41,7 @@ SECTIONS {
         PROVIDE(_bss_start = .);
         *(.sbss .sbss.*)
         *(.bss .bss.*)
-        . = ALIGN(4096);
+        . = ALIGN(512);
         PROVIDE(_bss_end = .);
     } >ram AT>ram :bss
 
@@ -51,8 +56,13 @@ SECTIONS {
     PROVIDE(_stack_end = _stack_start + 16384);
     PROVIDE(_tstack_start = _stack_end);
     PROVIDE(_tstack_end = _tstack_start + 16384);
-    PROVIDE(_virtio_virtqueue_start = _tstack_end);
+    PROVIDE(_heap_start = _tstack_end);
-    PROVIDE(_virtio_virtqueue_end = _virtio_virtqueue_start + 32768);
-    PROVIDE(_heap_start = _virtio_virtqueue_end);
     PROVIDE(_heap_size = _MEM_END - _heap_start);
+
+    PROVIDE(_virtio_queue_1_start = ORIGIN(virtqueues));
+    PROVIDE(_virtio_queue_1_end = _virtio_queue_1_start + 0x10000);
+    PROVIDE(_virtio_queue_2_start = _virtio_queue_1_end);
+    PROVIDE(_virtio_queue_2_end = _virtio_queue_2_start + 0x10000);
+
+    PROVIDE(_framebuffer_start = ORIGIN(framebuffer));
 }

src/dev/framebuffer/console.rs

@@ -0,0 +1,95 @@
+use crate::dev::framebuffer::{fb_clearscreen, fb_write_char_array};
+use crate::spinlock::Spinlock;
+use crate::trafficcontrol::TrafficControl;
+
+pub struct FramebufferConsole {
+    pub buffer: [[char; 20]; 15], // our font is 16x16, 320x240 is the standard res, so 20x15
+    pub cursor: (usize, usize),   // (x, y)
+    pub need_screen_clear: bool,
+}
+
+pub static FBCONSOLE: Spinlock<FramebufferConsole> = Spinlock::new(FramebufferConsole::empty());
+
+impl FramebufferConsole {
+    pub const fn empty() -> Self {
+        Self {
+            buffer: [[' '; 20]; 15],
+            cursor: (0, 0),
+            need_screen_clear: true,
+        }
+    }
+
+    // does NOT send a framebuffer update! that's up to the caller
+    pub fn scroll_terminal(&mut self) {
+        for line_num in 0..(self.buffer.len() - 1) {
+            let copy_from = self.buffer[line_num + 1];
+            self.buffer[line_num] = copy_from;
+        }
+        self.buffer[self.buffer.len() - 1] = [' '; 20];
+        self.need_screen_clear = true;
+    }
+
+    // DOES send a framebuffer update!
+    pub fn clear_terminal(&mut self, tc: &mut TrafficControl) {
+        self.need_screen_clear = false;
+        self.buffer = [[' '; 20]; 15];
+        self.cursor = (0, 0);
+        self.render(tc);
+    }
+
+    // DOES send a framebuffer update!
+    pub fn printstr(&mut self, tc: &mut TrafficControl, str: &str) {
+        for c in str.chars() {
+            let mut was_special_char = false;
+            if c == '\n' || c == '\r' {
+                was_special_char = true;
+                self.cursor.0 = 0;
+                self.cursor.1 += 1;
+            }
+            if self.cursor.1 >= self.buffer.len() {
+                self.cursor.0 = 0;
+                self.cursor.1 = self.buffer.len() - 1;
+                self.scroll_terminal();
+            }
+            if c == '\x08' {
+                was_special_char = true;
+                // we don't clear the character, that's up to the terminal
+                self.need_screen_clear = true;
+                if self.cursor.0 > 0 {
+                    self.cursor.0 -= 1;
+                } else {
+                    self.cursor.0 = 0;
+                    if self.cursor.1 > 0 {
+                        self.cursor.1 -= 1;
+                        self.cursor.0 = self.buffer[self.cursor.1].len() - 1;
+                    }
+                }
+            }
+            if !was_special_char {
+                self.buffer[self.cursor.1][self.cursor.0] = c;
+                self.cursor.0 += 1;
+                if self.cursor.0 >= self.buffer[self.cursor.1].len() {
+                    self.cursor.0 = 0;
+                    self.cursor.1 += 1;
+                    if self.cursor.1 >= self.buffer.len() {
+                        self.cursor.1 = self.buffer.len() - 1;
+                        self.scroll_terminal();
+                    }
+                }
+            }
+        }
+
+        self.render(tc);
+    }
+
+    pub fn render(&mut self, tc: &mut TrafficControl) {
+        if self.need_screen_clear {
+            fb_clearscreen(tc);
+            self.need_screen_clear = false;
+        }
+
+        for (y, line) in self.buffer.iter().enumerate() {
+            fb_write_char_array(tc, 0, y * 16, line);
+        }
+    }
+}

src/dev/framebuffer/mod.rs

@@ -0,0 +1,106 @@
+use crate::dev::virtio::framebuffer_update;
+use crate::dev::{FRAMEBUFFER_ADDR, FRAMEBUFFER_BPP, FRAMEBUFFER_HEIGHT, FRAMEBUFFER_WIDTH};
+use crate::trafficcontrol::TrafficControl;
+use core::sync::atomic::Ordering;
+
+pub mod console;
+
+pub const VAPFONT: &[u8] = include_bytes!("./vapfont.data");
+pub const VAPFONT_W: usize = 256;
+pub const VAPFONT_H: usize = 112;
+
+pub struct FBColor {
+    pub red: u8,
+    pub green: u8,
+    pub blue: u8,
+}
+
+pub const FB_BG_COLOR: FBColor = FBColor {
+    red: 216,
+    green: 216,
+    blue: 216,
+};
+
+pub const FB_FG_COLOR: FBColor = FBColor {
+    red: 0,
+    green: 0,
+    blue: 0,
+};
+
+impl FBColor {
+    #[inline]
+    pub const fn to_bytes(&self) -> [u8; 3] {
+        [self.red, self.green, self.blue]
+    }
+}
+
+pub fn fb_write_char_array(tc: &mut TrafficControl, mut x: usize, y: usize, chars: &[char]) {
+    let ogx = x;
+    let ogy = y;
+    const BYTES: [u8; 3] = FB_FG_COLOR.to_bytes();
+    let fbaddr = FRAMEBUFFER_ADDR.load(Ordering::Relaxed);
+    if fbaddr == 0 {
+        return;
+    }
+    let fbstride = FRAMEBUFFER_BPP.load(Ordering::Relaxed) * FRAMEBUFFER_WIDTH;
+    const CHAR_SIZE: usize = 16;
+    for c in chars {
+        let c = *c;
+        if c == ' ' {
+            x += CHAR_SIZE;
+        } else if c as u8 > 32 {
+            let c = c as u8 - 32;
+            let cx = (c % 16) as usize * CHAR_SIZE;
+            let cy = (c / 16) as usize * CHAR_SIZE;
+            for row in 0..CHAR_SIZE {
+                for col in 0..CHAR_SIZE {
+                    let coff = (VAPFONT_W * (cy + row)) + (cx + col);
+                    let draw = VAPFONT[coff / 8] & (0x80 >> (coff % 8));
+                    if draw != 0 {
+                        unsafe {
+                            let fb = (fbaddr as *mut u8)
+                                .add(((y + row) * fbstride) + ((x + col) * 4))
+                                as *mut u32;
+                            fb.write_volatile(u32::from_ne_bytes([
+                                0, BYTES[0], BYTES[1], BYTES[2],
+                            ]));
+                        }
+                    }
+                }
+            }
+            x += CHAR_SIZE;
+        }
+    }
+
+    framebuffer_update(
+        tc,
+        0,
+        0,
+        FRAMEBUFFER_WIDTH as u32,
+        FRAMEBUFFER_HEIGHT as u32,
+    );
+}
+
+pub fn fb_clearscreen(tc: &mut TrafficControl) {
+    const BYTES: [u8; 3] = FB_BG_COLOR.to_bytes();
+    let fbaddr = FRAMEBUFFER_ADDR.load(Ordering::Relaxed);
+    if fbaddr == 0 {
+        return;
+    }
+    let fbstride = FRAMEBUFFER_BPP.load(Ordering::Relaxed) * FRAMEBUFFER_WIDTH;
+    for y in 0..FRAMEBUFFER_HEIGHT {
+        for x in 0..FRAMEBUFFER_WIDTH {
+            unsafe {
+                let fb = (fbaddr as *mut u8).add(((y) * fbstride) + ((x) * 4)) as *mut u32;
+                fb.write_volatile(u32::from_ne_bytes([0, BYTES[0], BYTES[1], BYTES[2]]));
+            }
+        }
+    }
+    framebuffer_update(
+        tc,
+        0,
+        0,
+        FRAMEBUFFER_WIDTH as u32,
+        FRAMEBUFFER_HEIGHT as u32,
+    );
+}

src/dev/mod.rs

@@ -1,7 +1,22 @@
+use core::sync::atomic::{AtomicUsize, Ordering};
 use crate::trafficcontrol::TrafficControl;
 
+pub const FRAMEBUFFER_WIDTH: usize = 320;
+pub const FRAMEBUFFER_HEIGHT: usize = 240;
+
+pub const LINEBUFFER_BLOCKS: usize = 3;
+pub const LINEBUFFER_HEIGHT: usize = 1;
+
+// NOTE:
+// FRAMEBUFFER_ADDR should always be 0 if no framebuffer exists
+// if FRAMEBUFFER_ADDR is NOT 0, then FRAMEBUFFER_BPP should also be NOT 0
+pub static FRAMEBUFFER_ADDR: AtomicUsize = AtomicUsize::new(0);
+pub static FRAMEBUFFER_BPP: AtomicUsize = AtomicUsize::new(0);
+
 #[cfg(feature = "dev_virtio")]
 pub mod virtio;
+#[cfg(feature = "dev_framebuffer")]
+pub mod framebuffer;
 
 pub fn probe_devices(tc: &mut TrafficControl) {
     #[cfg(feature = "dev_virtio")]
@@ -12,4 +27,18 @@ pub fn read_sector(tc: &mut TrafficControl, buffer: usize, size: u32, sector: u6
     #[cfg(feature = "dev_virtio")]
     return virtio::read_sector(tc, buffer, size, sector);
     false
+}
+
+pub fn framebuffer_address() -> usize {
+    FRAMEBUFFER_ADDR.load(Ordering::Relaxed)
+}
+
+pub fn framebuffer_bpp() -> usize {
+    FRAMEBUFFER_BPP.load(Ordering::Relaxed)
+}
+
+
+pub fn framebuffer_push(tc: &mut TrafficControl, x: u32, y: u32, w: u32, h: u32) {
+    #[cfg(feature = "dev_virtio")]
+    virtio::framebuffer_update(tc, x, y, w, h);
 }

src/dev/virtio/block.rs

@@ -1,9 +1,18 @@
-use crate::dev::virtio::{Descriptor, VIRTIO_DESC_F_NEXT, VIRTIO_DESC_F_WRITE, VIRTIO_MMIO_GUEST_FEATURES, VIRTIO_MMIO_GUEST_PAGE_SIZE, VIRTIO_MMIO_HOST_FEATURES, VIRTIO_MMIO_QUEUE_NOTIFY, VIRTIO_MMIO_QUEUE_NUM, VIRTIO_MMIO_QUEUE_NUM_MAX, VIRTIO_MMIO_QUEUE_PFN, VIRTIO_MMIO_QUEUE_SEL, VIRTIO_MMIO_STATUS, VIRTIO_MMIO_STATUS_ACKNOWLEDGE, VIRTIO_MMIO_STATUS_DRIVER, VIRTIO_MMIO_STATUS_DRIVER_OK, VIRTIO_MMIO_STATUS_FAILED, VIRTIO_MMIO_STATUS_FEATURES_OK, VIRTIO_QUEUE_SIZE, VirtQueue, Used};
+use crate::dev::virtio::{
+    Descriptor, Used, VIRTIO_DESC_F_NEXT, VIRTIO_DESC_F_WRITE, VIRTIO_MMIO_GUEST_FEATURES,
+    VIRTIO_MMIO_GUEST_PAGE_SIZE, VIRTIO_MMIO_HOST_FEATURES, VIRTIO_MMIO_QUEUE_NOTIFY,
+    VIRTIO_MMIO_QUEUE_NUM, VIRTIO_MMIO_QUEUE_NUM_MAX, VIRTIO_MMIO_QUEUE_PFN, VIRTIO_MMIO_QUEUE_SEL,
+    VIRTIO_MMIO_STATUS, VIRTIO_MMIO_STATUS_ACKNOWLEDGE, VIRTIO_MMIO_STATUS_DRIVER,
+    VIRTIO_MMIO_STATUS_DRIVER_OK, VIRTIO_MMIO_STATUS_FAILED, VIRTIO_MMIO_STATUS_FEATURES_OK,
+    VIRTIO_QUEUE_SIZE, VirtQueue,
+};
+use crate::strprint::u32_hex;
 use crate::trafficcontrol::{TaskWait, TrafficControl};
 
 unsafe extern "C" {
-    fn _virtio_virtqueue_start();
+    fn _virtio_queue_1_start();
 }
+
 #[repr(C)]
 pub struct Status {
     pub status: u8,
@@ -57,7 +66,7 @@ impl VirtIoBlockDevice {
         // read host features
         let host_features =
             unsafe { ((addr + VIRTIO_MMIO_HOST_FEATURES) as *const u32).read_volatile() };
-        let guest_features = host_features & !(1 << 5);
+        let guest_features = 0;
         let read_only = host_features & (1 << 5) != 0;
 
         unsafe {
@@ -96,8 +105,19 @@ impl VirtIoBlockDevice {
         unsafe {
             ((addr + VIRTIO_MMIO_QUEUE_SEL) as *mut u32).write_volatile(0);
         }
-        let queue_ptr= _virtio_virtqueue_start as usize;
+        let num_blocks = size_of::<VirtQueue>().div_ceil(512) + 8; // 8 extra blocks will assert that the queue is aligned to 4096 bytes
-        unsafe { ((addr + VIRTIO_MMIO_GUEST_PAGE_SIZE) as *mut u32).write_volatile(4096) }; // who knows if this actually works :p
+        //let queue_block = unsafe { tc.memory_manager.as_mut().unwrap_unchecked().alloc_n_blocks(num_blocks) };
+        //let queue_ptr = unsafe { tc.memory_manager.as_mut().unwrap_unchecked().block_to_addr(queue_block) };
+        //// align up to 4096
+        //let queue_ptr = queue_ptr.wrapping_add(4095) & !(4095);
+        let queue_ptr = _virtio_queue_1_start as usize;
+        // zero out queue
+        for i in 0..size_of::<VirtQueue>() {
+            unsafe {
+                ((queue_ptr + i) as *mut u8).write_volatile(0);
+            }
+        }
+        unsafe { ((addr + VIRTIO_MMIO_GUEST_PAGE_SIZE) as *mut u32).write_volatile(4096) };
         unsafe {
             ((addr + VIRTIO_MMIO_QUEUE_PFN) as *mut u32).write_volatile(queue_ptr as u32 / 4096)
         };
@@ -147,10 +167,9 @@ impl VirtIoBlockDevice {
             return;
         }
 
-        let blk_request = {
+        let blk_request =
-            let block = unsafe { tc.memory_manager.as_mut().unwrap_unchecked() }.alloc_one_block();
+            { unsafe { tc.memory_manager.as_mut().unwrap_unchecked() }.alloc_one_block() }
-                unsafe { tc.memory_manager.as_mut().unwrap_unchecked().block_to_addr(block) }
+                as *mut Request;
-        } as *mut Request;
         let desc = Descriptor {
             addr: unsafe { &(*blk_request) as *const _ as u64 },
             len: size_of::<Request>() as u32,
@@ -211,8 +230,18 @@ impl VirtIoBlockDevice {
 
             let tid = unsafe { (*rq).tid };
 
-            let rq_block = unsafe { tc.memory_manager.as_mut().unwrap_unchecked() }.addr_to_block(rq as usize);
+            unsafe {
-            unsafe { tc.memory_manager.as_mut().unwrap_unchecked().free_one_block(rq_block); }
+                tc.memory_manager
+                    .as_mut()
+                    .unwrap_unchecked()
+                    .free_n_blocks(rq as usize, 1);
+            }
+            let actually_freed = unsafe {
+                tc.memory_manager
+                    .as_mut()
+                    .unwrap_unchecked()
+                    .is_addr_free(rq as usize)
+            };
 
             // awaken
             if let Some(Some(task)) = tc.tasks.get_mut(tid as usize) {

src/dev/virtio/gpu.rs

@@ -0,0 +1,493 @@
+use crate::arch::serial_port;
+use crate::dev::{FRAMEBUFFER_HEIGHT, FRAMEBUFFER_WIDTH, LINEBUFFER_BLOCKS};
+use crate::dev::virtio::{heap_allocate_type, Descriptor, VirtQueue, VIRTIO_DESC_F_NEXT, VIRTIO_DESC_F_WRITE, VIRTIO_MMIO_GUEST_FEATURES, VIRTIO_MMIO_GUEST_PAGE_SIZE, VIRTIO_MMIO_HOST_FEATURES, VIRTIO_MMIO_QUEUE_NOTIFY, VIRTIO_MMIO_QUEUE_NUM, VIRTIO_MMIO_QUEUE_NUM_MAX, VIRTIO_MMIO_QUEUE_PFN, VIRTIO_MMIO_QUEUE_SEL, VIRTIO_MMIO_STATUS, VIRTIO_MMIO_STATUS_ACKNOWLEDGE, VIRTIO_MMIO_STATUS_DRIVER, VIRTIO_MMIO_STATUS_DRIVER_OK, VIRTIO_MMIO_STATUS_FAILED, VIRTIO_MMIO_STATUS_FEATURES_OK, VIRTIO_QUEUE_SIZE};
+use crate::strprint::u32_hex;
+use crate::trafficcontrol::TrafficControl;
+
+unsafe extern "C" {
+    fn _virtio_queue_2_start();
+    fn _framebuffer_start();
+}
+
+pub const VIRTIO_GPU_CMD_GET_DISPLAY_INFO: u32 = 0x0100;
+
+#[repr(C)]
+pub struct CtrlHeader {
+    pub ctrl_type: u32,
+    pub flags: u32,
+    pub fence_id: u64,
+    pub ctx_id: u32,
+    pub ring_idx: u8,
+    pub padding: [u8; 3],
+}
+
+pub const VIRTIO_GPU_CMD_RESOURCE_CREATE_2D: u32 = 0x0100 + 1;
+pub const VIRTIO_GPU_FORMAT_X8R8G8B8: u32 = 4;
+
+#[repr(C)]
+pub struct ResourceCreate2D {
+    pub header: CtrlHeader,
+    pub resource_id: u32,
+    pub format: u32,
+    pub width: u32,
+    pub height: u32,
+}
+
+pub const VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING: u32 = 0x0100 + 6;
+#[repr(C)]
+pub struct ResourceAttachBacking {
+    pub header: CtrlHeader,
+    pub resource_id: u32,
+    pub nr_entries: u32,
+}
+
+#[repr(C)]
+pub struct GPUMemEntry {
+    pub addr: u64,
+    pub length: u32,
+    pub padding: u32,
+}
+
+pub const VIRTIO_GPU_CMD_SET_SCANOUT: u32 = 0x0100 + 3;
+
+#[repr(C)]
+pub struct SetScanout {
+    pub header: CtrlHeader,
+    pub rect: VirtIoGpuRect,
+    pub scanout_id: u32,
+    pub resource_id: u32,
+}
+
+#[repr(C)]
+pub struct VirtIoGpuRect {
+    pub x: u32,
+    pub y: u32,
+    pub width: u32,
+    pub height: u32,
+}
+
+pub const VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D: u32 = 0x0100 + 5;
+
+#[repr(C)]
+pub struct TransferToHost2D {
+    pub header: CtrlHeader,
+    pub rect: VirtIoGpuRect,
+    pub offset: u64,
+    pub resource_id: u32,
+    pub padding: u32,
+}
+
+pub const VIRTIO_GPU_CMD_RESOURCE_FLUSH: u32 = 0x0100 + 4;
+
+#[repr(C)]
+pub struct ResourceFlush {
+    pub header: CtrlHeader,
+    pub rect: VirtIoGpuRect,
+    pub resource_id: u32,
+    pub padding: u32,
+}
+
+pub struct VirtIoGpuDevice {
+    pub latest_response: usize,
+    pub addr: usize,
+    pub queue: usize,
+    pub idx: u16,
+    pub ack_used_idx: u16,
+    pub framebuffer: usize,
+    pub width: usize,
+    pub height: usize,
+}
+
+pub enum VirtIoGpuDeviceError {
+    FeatureSetMismatch,
+    QueueSetupFailed,
+}
+
+impl VirtIoGpuDevice {
+    pub fn new_and_init(
+        tc: &mut TrafficControl,
+        addr: usize,
+    ) -> Result<Self, VirtIoGpuDeviceError> {
+        // reset device (write 0 to status)
+        unsafe {
+            ((addr + VIRTIO_MMIO_STATUS) as *mut u32).write_volatile(0);
+        }
+        // set ack bit
+        let mut status = VIRTIO_MMIO_STATUS_ACKNOWLEDGE;
+        unsafe {
+            ((addr + VIRTIO_MMIO_STATUS) as *mut u32).write_volatile(status);
+        }
+        // set driver bit
+        status |= VIRTIO_MMIO_STATUS_DRIVER;
+        unsafe {
+            ((addr + VIRTIO_MMIO_STATUS) as *mut u32).write_volatile(status);
+        }
+        // read host features
+        let host_features =
+        unsafe { ((addr + VIRTIO_MMIO_HOST_FEATURES) as *const u32).read_volatile() };
+        let guest_features = 0; // todo: configure properly
+
+        unsafe {
+            ((addr + VIRTIO_MMIO_GUEST_FEATURES) as *mut u32).write_volatile(guest_features);
+        }
+        status |= VIRTIO_MMIO_STATUS_FEATURES_OK;
+        unsafe {
+            ((addr + VIRTIO_MMIO_STATUS) as *mut u32).write_volatile(status);
+        }
+        // make sure features ok is still set, otherwise failed
+        if unsafe { ((addr + VIRTIO_MMIO_STATUS) as *const u32).read_volatile() }
+            & VIRTIO_MMIO_STATUS_FEATURES_OK
+            == 0
+        {
+            unsafe {
+                ((addr + VIRTIO_MMIO_STATUS) as *mut u32).write_volatile(VIRTIO_MMIO_STATUS_FAILED);
+            }
+            return Err(VirtIoGpuDeviceError::FeatureSetMismatch);
+        }
+
+        // setup queue
+        let queue_max_by_device =
+            unsafe { ((addr + VIRTIO_MMIO_QUEUE_NUM_MAX) as *const u32).read_volatile() };
+        if queue_max_by_device < VIRTIO_QUEUE_SIZE as _ {
+            unsafe {
+                ((addr + VIRTIO_MMIO_STATUS) as *mut u32).write_volatile(VIRTIO_MMIO_STATUS_FAILED);
+            }
+            return Err(VirtIoGpuDeviceError::QueueSetupFailed);
+        }
+        unsafe {
+            ((addr + VIRTIO_MMIO_QUEUE_NUM) as *mut u32).write_volatile(VIRTIO_QUEUE_SIZE as _);
+        }
+        unsafe {
+            ((addr + VIRTIO_MMIO_QUEUE_SEL) as *mut u32).write_volatile(0);
+        }
+
+        //let num_blocks = size_of::<VirtQueue>().div_ceil(512) + 8; // 8 extra blocks will assert that the queue is aligned to 4096 bytes
+        //let queue_block= unsafe { tc.memory_manager.as_mut().unwrap_unchecked().alloc_n_blocks(num_blocks) };
+        //let queue_ptr = unsafe { tc.memory_manager.as_mut().unwrap_unchecked().block_to_addr(queue_block) };
+        //// align up to 4096
+        //let queue_ptr = queue_ptr.wrapping_add(4095) & !(4095);
+        let queue_ptr = _virtio_queue_2_start as usize;
+        // zero out queue
+        for i in 0..size_of::<VirtQueue>() {
+            unsafe {
+                ((queue_ptr + i) as *mut u8).write_volatile(0);
+            }
+        }
+        unsafe {
+            ((addr + VIRTIO_MMIO_GUEST_PAGE_SIZE) as *mut u32).write_volatile(4096);
+        }
+        unsafe {
+            ((addr + VIRTIO_MMIO_QUEUE_PFN) as *mut u32).write_volatile(queue_ptr as u32 / 4096);
+        }
+
+
+        // allocate memory for framebuffer
+        let framebuffer_ptr = _framebuffer_start as usize;
+
+        let latest_response = heap_allocate_type::<CtrlHeader>(tc) as *const _ as usize;
+
+        let mut gpu = Self {
+            latest_response,
+            addr,
+            queue: queue_ptr,
+            idx: 0,
+            ack_used_idx: 0,
+            framebuffer: framebuffer_ptr,
+            width: FRAMEBUFFER_WIDTH,
+            height: FRAMEBUFFER_HEIGHT,
+        };
+        status |= VIRTIO_MMIO_STATUS_DRIVER_OK;
+        unsafe {
+            ((addr + VIRTIO_MMIO_STATUS) as *mut u32).write_volatile(status);
+        }
+
+        let mut free_me = [0; 4];
+
+        // create host resource 1, ResourceCreate2D
+        let cmd = heap_allocate_type::<ResourceCreate2D>(tc);
+        cmd.header.ctrl_type = VIRTIO_GPU_CMD_RESOURCE_CREATE_2D;
+        cmd.header.flags = 0;
+        cmd.header.fence_id = 0;
+        cmd.header.ctx_id = 0;
+        cmd.header.ring_idx = 0;
+        cmd.header.padding = [0; 3];
+
+        cmd.resource_id = 1;
+        cmd.format = VIRTIO_GPU_FORMAT_X8R8G8B8;
+        cmd.width = FRAMEBUFFER_WIDTH as u32;
+        cmd.height = FRAMEBUFFER_HEIGHT as u32;
+        free_me[0] = unsafe { &(*cmd) as *const _ as usize };
+
+        let desc_rq = Descriptor {
+            addr: unsafe { &(*cmd) as *const _ as u64 },
+            len: size_of::<ResourceCreate2D>() as u32,
+            flags: VIRTIO_DESC_F_NEXT,
+            next: 0,
+        };
+        let desc_resp = Descriptor {
+            addr: gpu.latest_response as u64,
+            len: size_of::<CtrlHeader>() as u32,
+            flags: VIRTIO_DESC_F_WRITE,
+            next: 0,
+        };
+
+        gpu.send_rq_rsp(desc_rq, desc_resp);
+        // awful hack so that we don't overload the queue
+        while {
+            gpu.ack_used_idx == unsafe { (gpu.queue as *const VirtQueue).read_volatile().used.idx }
+        } {
+
+        }
+        //gpu.pending(tc);
+
+        // attach backing, ResourceAttachBacking
+        let cmd = heap_allocate_type::<ResourceAttachBacking>(tc);
+        cmd.header.ctrl_type = VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING;
+        cmd.header.flags = 0;
+        cmd.header.fence_id = 0;
+        cmd.header.ctx_id = 0;
+        cmd.header.ring_idx = 0;
+        cmd.header.padding = [0; 3];
+        cmd.resource_id = 1;
+        cmd.nr_entries = 1;
+        free_me[1] = unsafe { &(*cmd) as *const _ as usize };
+        let mem_entry = heap_allocate_type::<GPUMemEntry>(tc);
+        mem_entry.addr = gpu.framebuffer as u64;
+        mem_entry.length = (gpu.height * gpu.width * 4) as u32;
+        mem_entry.padding = 0;
+        free_me[2] = unsafe { &(*mem_entry) as *const _ as usize };
+
+        let desc_rq = Descriptor {
+            addr: unsafe { &(*cmd) as *const _ as u64 },
+            len: size_of::<ResourceAttachBacking>() as u32,
+            flags: VIRTIO_DESC_F_NEXT,
+            next: 0,
+        };
+        let desc_mem_entry = Descriptor {
+            addr: unsafe { &(*mem_entry) as *const _ as u64 },
+            len: size_of::<GPUMemEntry>() as u32,
+            flags: VIRTIO_DESC_F_NEXT,
+            next: 0,
+        };
+        let desc_resp = Descriptor {
+            addr: gpu.latest_response as u64,
+            len: size_of::<CtrlHeader>() as u32,
+            flags: VIRTIO_DESC_F_WRITE,
+            next: 0,
+        };
+
+        gpu.send_rq_next_rsp([desc_rq, desc_mem_entry], desc_resp);
+        // awful hack so that we don't overload the queue
+        while {
+            gpu.ack_used_idx == unsafe { (gpu.queue as *const VirtQueue).read_volatile().used.idx }
+        } {
+
+        }
+        //gpu.pending(tc);
+
+        // set scanout
+        let cmd = heap_allocate_type::<SetScanout>(tc);
+        cmd.header.ctrl_type = VIRTIO_GPU_CMD_SET_SCANOUT;
+        cmd.header.flags = 0;
+        cmd.header.fence_id = 0;
+        cmd.header.ctx_id = 0;
+        cmd.header.ring_idx = 0;
+        cmd.header.padding = [0; 3];
+        cmd.rect.x = 0;
+        cmd.rect.y = 0;
+        cmd.rect.width = gpu.width as u32;
+        cmd.rect.height = gpu.height as u32;
+        cmd.scanout_id = 0;
+        cmd.resource_id = 1;
+        free_me[3] = unsafe { &(*cmd) as *const _ as usize };
+
+        let desc_rq = Descriptor {
+            addr: unsafe { &(*cmd) as *const _ as u64 },
+            len: size_of::<SetScanout>() as u32,
+            flags: VIRTIO_DESC_F_NEXT,
+            next: 0,
+        };
+        let desc_resp = Descriptor {
+            addr: gpu.latest_response as u64,
+            len: size_of::<CtrlHeader>() as u32,
+            flags: VIRTIO_DESC_F_WRITE,
+            next: 0,
+        };
+        gpu.send_rq_rsp(desc_rq, desc_resp);
+        // awful hack so that we don't overload the queue
+        while {
+            gpu.ack_used_idx == unsafe { (gpu.queue as *const VirtQueue).read_volatile().used.idx }
+        } {
+
+        }
+        gpu.pending(tc);
+
+        for free in free_me {
+            unsafe {
+                tc.memory_manager.as_mut().unwrap_unchecked().free_n_blocks(free, 1);
+            }
+        }
+
+        Ok(gpu)
+    }
+
+    pub fn send_rq_rsp(&mut self, desc_rq: Descriptor, desc_resp: Descriptor) {
+        self.idx = (self.idx + 1) % VIRTIO_QUEUE_SIZE as u16;
+        let head = self.idx;
+        unsafe {
+            (*(self.queue as *mut VirtQueue)).desc[self.idx as usize] = desc_rq;
+        }
+
+        // assume next is always set
+        unsafe {
+            //(*(self.queue as *mut VirtQueue)).desc[self.idx as usize].flags |= VIRTIO_DESC_F_NEXT;
+
+            (*(self.queue as *mut VirtQueue)).desc[self.idx as usize].next =
+                (self.idx + 1) % VIRTIO_QUEUE_SIZE as u16;
+        }
+
+        self.idx = (self.idx + 1) % VIRTIO_QUEUE_SIZE as u16;
+        unsafe {
+            (*(self.queue as *mut VirtQueue)).desc[self.idx as usize] = desc_resp;
+        }
+
+        unsafe {
+            (*(self.queue as *mut VirtQueue)).avail.ring
+                [(*(self.queue as *mut VirtQueue)).avail.idx as usize % VIRTIO_QUEUE_SIZE] = head;
+        }
+        unsafe {
+            (*(self.queue as *mut VirtQueue)).avail.idx =
+                (*(self.queue as *mut VirtQueue)).avail.idx.wrapping_add(1);
+        }
+
+        // notify
+        unsafe {
+            ((self.addr + VIRTIO_MMIO_QUEUE_NOTIFY) as *mut u32).write_volatile(0);
+        }
+    }
+
+    pub fn send_rq_next_rsp<T: Sized + IntoIterator<Item = Descriptor>>(&mut self, descs: T, desc_resp: Descriptor) {
+        let head = (self.idx + 1) % VIRTIO_QUEUE_SIZE as u16;
+        for desc in descs {
+            self.idx = (self.idx + 1) % VIRTIO_QUEUE_SIZE as u16;
+            unsafe {
+                (*(self.queue as *mut VirtQueue)).desc[self.idx as usize] = desc;
+            }
+
+            // assume next is always set
+            unsafe {
+                (*(self.queue as *mut VirtQueue)).desc[self.idx as usize].next =
+                    (self.idx + 1) % VIRTIO_QUEUE_SIZE as u16;
+            }
+        }
+
+        self.idx = (self.idx + 1) % VIRTIO_QUEUE_SIZE as u16;
+        unsafe {
+            (*(self.queue as *mut VirtQueue)).desc[self.idx as usize] = desc_resp;
+        }
+
+        unsafe {
+            (*(self.queue as *mut VirtQueue)).avail.ring
+                [(*(self.queue as *mut VirtQueue)).avail.idx as usize % VIRTIO_QUEUE_SIZE] = head;
+        }
+        unsafe {
+            (*(self.queue as *mut VirtQueue)).avail.idx =
+                (*(self.queue as *mut VirtQueue)).avail.idx.wrapping_add(1);
+        }
+
+        // notify
+        unsafe {
+            ((self.addr + VIRTIO_MMIO_QUEUE_NOTIFY) as *mut u32).write_volatile(0);
+        }
+    }
+
+    // WARNING: THIS VERSION OF PENDING DOES NOT FREE ANYTHING
+    pub fn pending(&mut self, tc: &mut TrafficControl) {
+        let queue = unsafe { &(*(self.queue as *mut VirtQueue)) };
+        while self.ack_used_idx != queue.used.idx {
+            self.ack_used_idx = self.ack_used_idx.wrapping_add(1);
+        }
+    }
+
+    pub fn transfer(&mut self, tc: &mut TrafficControl, x: u32, y: u32, w: u32, h: u32) {
+        let mut free_me = [0; 2];
+
+        let cmd = heap_allocate_type::<TransferToHost2D>(tc);
+        cmd.header.ctrl_type = VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D;
+        cmd.header.flags = 0;
+        cmd.header.fence_id = 0;
+        cmd.header.ctx_id = 0;
+        cmd.header.ring_idx = 0;
+        cmd.header.padding = [0; 3];
+        cmd.rect.x = x;
+        cmd.rect.y = y;
+        cmd.rect.width = w;
+        cmd.rect.height = h;
+        cmd.offset = 0;
+        cmd.resource_id = 1;
+        cmd.padding = 0;
+        free_me[0] = unsafe { &(*cmd) as *const _ as usize };
+
+        let desc_rq = Descriptor {
+            addr: unsafe { &(*cmd) as *const _ as u64 },
+            len: size_of::<TransferToHost2D>() as u32,
+            flags: VIRTIO_DESC_F_NEXT,
+            next: 0,
+        };
+        let desc_resp = Descriptor {
+            addr: self.latest_response as u64,
+            len: size_of::<CtrlHeader>() as u32,
+            flags: VIRTIO_DESC_F_WRITE,
+            next: 0,
+        };
+
+        self.send_rq_rsp(desc_rq, desc_resp);
+        //self.pending(tc);
+
+        // resource flush
+        let cmd = heap_allocate_type::<ResourceFlush>(tc);
+        cmd.header.ctrl_type = VIRTIO_GPU_CMD_RESOURCE_FLUSH;
+        cmd.header.flags = 0;
+        cmd.header.fence_id = 0;
+        cmd.header.ctx_id = 0;
+        cmd.header.ring_idx = 0;
+        cmd.header.padding = [0; 3];
+        cmd.rect.x = x;
+        cmd.rect.y = y;
+        cmd.rect.width = w;
+        cmd.rect.height = h;
+        cmd.resource_id = 1;
+        cmd.padding = 0;
+        free_me[1] = unsafe { &(*cmd) as *const _ as usize };
+
+        let desc_rq = Descriptor {
+            addr: unsafe { &(*cmd) as *const _ as u64 },
+            len: size_of::<ResourceFlush>() as u32,
+            flags: VIRTIO_DESC_F_NEXT,
+            next: 0,
+        };
+        let desc_resp = Descriptor {
+            addr: self.latest_response as u64,
+            len: size_of::<CtrlHeader>() as u32,
+            flags: VIRTIO_DESC_F_WRITE,
+            next: 0,
+        };
+
+        self.send_rq_rsp(desc_rq, desc_resp);
+
+        // hack to make sure the queue doesn't get overloaded
+        while {
+            let queue = unsafe { (self.queue as *mut VirtQueue).read_volatile() };
+            self.ack_used_idx == queue.used.idx
+        } {
+
+        }
+        self.pending(tc);
+
+        for free in free_me.into_iter() {
+            unsafe {
+                tc.memory_manager.as_mut().unwrap_unchecked().free_n_blocks(free, 1);
+            }
+        }
+    }
+}

src/dev/virtio/mod.rs

@@ -1,12 +1,17 @@
 //! virtio devices
 //! WARNING: virtio is currently completely broken! don't use it!
 
+use core::sync::atomic::Ordering;
+use crate::dev::{FRAMEBUFFER_ADDR, FRAMEBUFFER_BPP};
 use crate::dev::virtio::block::{VirtIoBlockDevice, VirtIoBlockDeviceError};
+use crate::dev::virtio::gpu::{VirtIoGpuDevice, VirtIoGpuDeviceError};
+use crate::rough_panic;
 use crate::spinlock::Spinlock;
 use crate::strprint::twodigit;
 use crate::trafficcontrol::{TrafficControl};
 
 mod block;
+mod gpu;
 
 pub const VIRTIO_MMIO_START: usize = 0x1000_1000;
 pub const VIRTIO_MMIO_END: usize = 0x1000_8000;
@@ -32,13 +37,15 @@ pub const VIRTIO_MMIO_STATUS_FAILED: u32 = 1 << 7;
 pub const VIRTIO_DESC_F_NEXT: u16 = 1 << 0;
 pub const VIRTIO_DESC_F_WRITE: u16 = 1 << 1;
 
-pub const VIRTIO_QUEUE_SIZE: usize = 4;
+pub const VIRTIO_QUEUE_SIZE: usize = 16;
 
 pub static VIRTIO_DEVICES: Spinlock<[Option<VirtIoDevice>; VIRTIO_MMIO_DEVCOUNT]> = Spinlock::new([const { None }; VIRTIO_MMIO_DEVCOUNT]);
 pub static VIRTIO_HARD_BLOCK_DEVICE: Spinlock<Option<u8>> = Spinlock::new(None);
+pub static VIRTIO_GPU_DEVICE: Spinlock<Option<u8>> = Spinlock::new(None);
 
 pub enum VirtIoDevice {
     BlockDevice(VirtIoBlockDevice),
+    GPUDevice(VirtIoGpuDevice),
 }
 
 #[repr(C)]
@@ -75,6 +82,15 @@ pub struct VirtQueue {
     pub used: Used,
 }
 
+pub fn heap_allocate_type<T: Sized>(tc: &mut TrafficControl) -> &'static mut T {
+    let num_blocks = size_of::<T>().div_ceil(512);
+    if num_blocks != 1 {
+        rough_panic(['f', 'm', 'l']);
+    }
+    let addr = unsafe { tc.memory_manager.as_mut().unwrap_unchecked().alloc_n_blocks(num_blocks) };
+    unsafe { &mut (*(addr as *mut T)) }
+}
+
 pub fn probe_virtio_devices(tc: &mut TrafficControl) {
     let serial_port = crate::arch::serial_port();
     let mut devices = VIRTIO_DEVICES.lock();
@@ -117,6 +133,32 @@ pub fn probe_virtio_devices(tc: &mut TrafficControl) {
                     }
                 }
             }
+            16 => {
+                // gpu device
+                let gpu_device = VirtIoGpuDevice::new_and_init(tc, addr);
+                if let Ok(gpu_device) = gpu_device {
+                    FRAMEBUFFER_ADDR.store(gpu_device.framebuffer, Ordering::Relaxed);
+                    FRAMEBUFFER_BPP.store(4, Ordering::Relaxed); // virtio always uses 4 byte stride
+                    devices[i] = Some(VirtIoDevice::GPUDevice(gpu_device));
+                    *VIRTIO_GPU_DEVICE.lock() = Some(i as u8);
+                    if let Some(serial_port) = &serial_port {
+                        serial_port.putstr("virtio gpu device found\n");
+                    }
+                } else if let Err(e) = gpu_device {
+                    match e {
+                        VirtIoGpuDeviceError::FeatureSetMismatch => {
+                            if let Some(serial_port) = &serial_port {
+                                serial_port.putstr("virtio gpu device feature mismatch\n");
+                            }
+                        }
+                        VirtIoGpuDeviceError::QueueSetupFailed => {
+                            if let Some(serial_port) = &serial_port {
+                                serial_port.putstr("virtio gpu device queue setup failed\n");
+                            }
+                        }
+                    }
+                }
+            }
             x => {
                 if let Some(serial_port) = &serial_port {
                     serial_port.putstr("unsupported device type ");
@@ -144,6 +186,18 @@ pub fn handle_interrupt(interrupt: u32, tc: &mut TrafficControl) {
                     }
                 }
             }
+            VirtIoDevice::GPUDevice(gpudev) => {
+                return;
+                let gpu = {
+                    let lock = VIRTIO_GPU_DEVICE.lock();
+                    *lock
+                };
+                if let Some(gpu) = gpu {
+                    if gpu as usize == idx {
+                        gpudev.pending(tc);
+                    }
+                }
+            }
         }
     }
 }
@@ -156,10 +210,48 @@ pub fn read_sector(tc: &mut TrafficControl, buffer: usize, size: u32, sector: u6
     let mut devices = VIRTIO_DEVICES.lock();
     if let Some(idx) = idx {
         if let Some(device) = devices[idx as usize].as_mut() {
-            match device {
+            return match device {
                 VirtIoDevice::BlockDevice(device) => {
                     device.operation(tc, buffer, size, sector, false);
-                    return true;
+                    true
+                }
+                _ => {
+                    if let Some(serial_port) = &crate::arch::serial_port() {
+                        serial_port.putstr("unexpected device type (not block)\n");
+                    }
+                    false
+                }
+            };
+        } else {
+            let uart = crate::uart::UART::new(0x1000_0000);
+            uart.putstr("no device")
+        }
+    } else {
+        let uart = crate::uart::UART::new(0x1000_0000);
+        uart.putstr("no idx")
+    }
+
+    false
+}
+
+pub fn framebuffer_update(tc: &mut TrafficControl, x: u32, y: u32, w: u32, h: u32) -> bool {
+    let idx = {
+        let lock = VIRTIO_GPU_DEVICE.lock();
+        *lock
+    };
+    let mut devices = VIRTIO_DEVICES.lock();
+    if let Some(idx) = idx {
+        if let Some(device) = devices[idx as usize].as_mut() {
+            return match device {
+                VirtIoDevice::GPUDevice(device) => {
+                    device.transfer(tc, x, y, w, h);
+                    true
+                }
+                _ => {
+                    if let Some(serial_port) = &crate::arch::serial_port() {
+                        serial_port.putstr("unexpected device type (not gpu)\n");
+                    }
+                    false
                 }
             }
         } else {

src/fs/fat32.rs

@@ -1,4 +1,5 @@
 use crate::fs::{Record, RecordType};
+use crate::strprint::u32_hex;
 
 #[repr(packed(1), C)]
 pub struct BPB {
@@ -286,9 +287,9 @@ pub fn seek_forward_one_sector(bpb: &BPBUseful, reader: &mut Fat32FileReader) ->
         }
         let table_value =
             unsafe { ((fat_addr+(ent_offset)) as *const u32).read_volatile() } & 0x0FFFFFFF;
+        crate::syscalls::free_blocks(fat_addr, 1);
         if table_value >= 0x0FFFFFF8 {
             // no more clusters, whole file has been read
-            crate::syscalls::free_blocks(fat_addr, 1);
             reader.eof = 1;
             return false;
         } else if table_value >= 0x00000002 {
@@ -298,12 +299,10 @@ pub fn seek_forward_one_sector(bpb: &BPBUseful, reader: &mut Fat32FileReader) ->
                 ((reader.cluster - 2) * bpb.sectors_per_cluster as usize) + bpb.first_data_sector();
             reader.sector_offset = 0;
             if table_value == 0x00000000 || table_value == 0x00000001 {
-                crate::syscalls::free_blocks(fat_addr, 1);
                 reader.eof = 1;
                 return false;
             } else if table_value == 0x0FFFFFF7 {
                 // bad cluster, stop reading
-                crate::syscalls::free_blocks(fat_addr, 1);
                 crate::syscalls::write_terminal(b"badcluster");
                 reader.eof = 1;
                 return false;
@@ -338,6 +337,7 @@ pub fn read_file(bpb: &BPBUseful, reader: &mut Fat32FileReader, buffer: &mut [u8
         let mut left_in_sector = 512 - reader.sector_offset;
         if left_in_sector == 0 {
             crate::syscalls::write_terminal(b"SECTORNULL?");
+            crate::syscalls::free_blocks(sector_addr, 1);
             return false;
         }
         while buffer_idx < buffer.len() && left_in_sector > 0 {

src/main.rs

@@ -32,16 +32,6 @@ pub extern "C" fn ktask() -> ! {
     syscalls::init_kernel();
     print(b"kernel ready!\n");
 
-    //let kinfo = kinfo();
-    //print(b"\nkinfo\n");
-    //print(b"task count ");
-    //print(&u32_hex(kinfo.current_process_count as u32));
-    //print(b"\ntotal mem ");
-    //print(&u32_hex(kinfo.total_mem_blocks as u32));
-    //print(b"\nfree mem ");
-    //print(&u32_hex(kinfo.free_mem_blocks as u32));
-    //print(b"\n");
-
     // load TURNTBL.DDI
 
     {
@@ -50,6 +40,7 @@ pub extern "C" fn ktask() -> ! {
             rough_panic(['f', 's', 'e']);
         }
 
+
         let mut fs = liblbos::fs::FileSystem::empty();
         if !fs::open_fs(unsafe { &mut *(&mut fs as *mut _ as *mut _) }) {
             fserr();

src/memory.rs

@@ -1,4 +1,6 @@
+use crate::arch::serial_port;
 use crate::rough_panic;
+use crate::strprint::u32_hex;
 
 #[cfg(feature = "arch_virt")]
 
@@ -8,25 +10,32 @@ unsafe extern "C" {
 }
 
 pub const BLOCK_SIZE: usize = 512;
-#[cfg(feature = "arch_virt")]
-pub const TOTAL_MEMORY: usize = 1048510;
-#[cfg(feature = "arch_ppc32")]
-pub const TOTAL_MEMORY: usize = 1024 * 1024; // 1MiB;
-pub const MEM_BLOCKS: usize = TOTAL_MEMORY / BLOCK_SIZE;
 
 pub struct MemoryManager {
     pub heap_start: usize,
     pub heap_size: usize,
-    pub blockmap: [u8; (MEM_BLOCKS+7) / 8],
+    pub blockmap: [u8; 128/8]
 }
 
 impl MemoryManager {
     #[cfg(feature = "arch_virt")]
     pub fn init() -> Self {
+        {
+            let uart = serial_port();
+            if let Some(uart) = uart {
+                uart.putstr("heap_start: ");
+                uart.put_bytes(&u32_hex(_heap_start as u32));
+                uart.putstr("totalmem: ");
+                uart.put_bytes(&u32_hex(_heap_size as u32));
+                uart.putstr("\n");
+            }
+        }
+
         Self {
             heap_start: _heap_start as _,
             heap_size: _heap_size as _,
-            blockmap: [0; (MEM_BLOCKS+7) / 8],
+
+            blockmap: [0; 16],
         }
     }
     #[cfg(feature = "arch_ppc32")]
@@ -38,14 +47,6 @@ impl MemoryManager {
         }
     }
 
-    pub fn block_to_addr(&self, block: usize) -> usize {
-        block * BLOCK_SIZE + self.heap_start
-    }
-    
-    pub fn addr_to_block(&self, addr: usize) -> usize {
-        (addr - self.heap_start) / BLOCK_SIZE
-    }
-    
     pub fn alloc_one_block(&mut self) -> usize {
         /*
         for (i, v) in self.blockmap.iter_mut().enumerate() {
@@ -64,11 +65,19 @@ impl MemoryManager {
          */
         self.alloc_n_blocks(1)
     }
-    pub fn free_one_block(&mut self, block: usize) {
+    pub fn free_one_block(&mut self, addr: usize) {
+        let block = (addr - self.heap_start) / BLOCK_SIZE;
         self.blockmap[block / 8] &= !(1 << (block % 8));
     }
-    
+
+    pub fn is_addr_free(&self, addr: usize) -> bool {
+        let block = (addr - self.heap_start) / BLOCK_SIZE;
+        let val = (1 << (block % 8)) & self.blockmap[block / 8];
+        val == 0
+    }
+
     // can easily fail if too many blocks are requested, will return 0 on failure
+    // RETURNS ADDRESS
     pub fn alloc_n_blocks(&mut self, n: usize) -> usize {
         if n == 0 {
             return 0;
@@ -78,46 +87,57 @@ impl MemoryManager {
         for i in 0..self.blockmap.len() {
             for j in 0..8 {
                 let block = i * 8 + j;
+                let valid = block < (self.heap_size / BLOCK_SIZE);
                 let val = (1 << j) & self.blockmap[i];
-                if val == 0 {
+                if val == 0 && valid {
                     // this is free
                     self.blockmap[i] |= 1 << j;
                     if first_block.is_none() {
                         first_block = Some(block);
                     }
                     found += 1;
-                    if found >= n {
+                    if found == n {
-                        return first_block.unwrap();
+                        let addr = (first_block.unwrap() * BLOCK_SIZE) + self.heap_start;
+                        return addr;
+                    }
+                    if found > n {
+                        rough_panic(['h', 'm', '?'])
                     }
                 } else {
                     // used, restart search
                     let mut i = 0;
                     while found > 0 {
                         found -= 1;
-                        self.free_one_block(first_block.unwrap() + i);
+                        let addr = ((first_block.unwrap() * BLOCK_SIZE) + self.heap_start) + (i * BLOCK_SIZE);
+                        self.free_one_block(addr);
                         i += 1;
                     }
                     first_block = None;
                 }
             }
         }
-        
+
-        0
+        rough_panic(['o', 'o', 'm'])
     }
     
-    pub fn free_n_blocks(&mut self, block: usize, n: usize) {
+    pub fn free_n_blocks(&mut self, addr: usize, n: usize) {
-        if n == 0 || block >= MEM_BLOCKS || block + n > MEM_BLOCKS {
+        if n == 0 || addr < self.heap_start || addr >= self.heap_start + self.heap_size || addr + n * BLOCK_SIZE > self.heap_start + self.heap_size {
-            return;
+            rough_panic(['b', 'm', 'f'])
         }
         for i in 0..n {
-            self.free_one_block(block + i);
+            self.free_one_block(addr + (i * BLOCK_SIZE));
         }
     }
     
     pub fn used_blocks(&self) -> usize {
         let mut used_blocks = 0;
-        for v in self.blockmap.iter() {
+        for (i, v) in self.blockmap.iter().enumerate() {
             for j in 0..8 {
+                let block = i * 8 + j;
+                let valid = block < (self.heap_size / BLOCK_SIZE);
+                if !valid {
+                    continue;
+                }
                 let val = (1 << j) & *v;
                 if val != 0 {
                     // used

src/trafficcontrol.rs

@@ -4,7 +4,8 @@ use crate::arch::serial_port;
 use crate::memory::{BLOCK_SIZE, MemoryManager};
 use crate::spinlock::Spinlock;
 use crate::syscalls::SysCall;
-use crate::{arch};
+use crate::{arch, rough_panic};
+use crate::strprint::u32_hex;
 
 #[repr(u32)]
 pub enum TaskWait {
@@ -13,6 +14,8 @@ pub enum TaskWait {
     WaitForTaskExit = 1 << 2,
 }
 
+pub const STACK_SIZE_IN_BLOCKS: usize = 8;
+
 pub const MAX_TASKS: usize = 8;
 
 pub static TC: Spinlock<TrafficControl> = Spinlock::new(TrafficControl::empty());
@@ -67,19 +70,12 @@ pub fn handle_syscall(
                 let add = a1 as *mut TaskSetup;
 
                 tc.init_mem_if_not();
-                let blockalloc = unsafe {
-                    tc.memory_manager
-                        .as_mut()
-                        .unwrap_unchecked()
-                        .alloc_n_blocks(16)
-                };
                 let sp = unsafe {
                     tc.memory_manager
                         .as_mut()
                         .unwrap_unchecked()
-                        .block_to_addr(blockalloc)
+                        .alloc_n_blocks(STACK_SIZE_IN_BLOCKS)
-                        + BLOCK_SIZE
+                } + (BLOCK_SIZE * STACK_SIZE_IN_BLOCKS);
-                };
 
                 #[cfg(feature = "arch_virt")]
                 let t = Some(Task {
@@ -91,10 +87,8 @@ pub fn handle_syscall(
                     incoming_notifications: [const { None }; MAX_TASKS],
                     ackwait: [0; MAX_TASKS],
                     task_wait: 0,
-                    ddi_mem_start_block: unsafe {
+                    ddi_mem_start: unsafe {
-                        tc.memory_manager
+                        (*add).ddi_first_addr
-                            .as_mut().unwrap_unchecked()
-                            .addr_to_block((*add).ddi_first_addr)
                     },
                     ddi_mem_blocks_count: unsafe { (*add).ddi_size / BLOCK_SIZE },
                     trap_frame: arch::virt::tasks::setup_task(sp),
@@ -132,7 +126,7 @@ pub fn handle_syscall(
                     tc.memory_manager
                         .as_mut()
                         .unwrap_unchecked()
-                        .free_one_block(blockalloc);
+                        .free_n_blocks(sp, 1);
                 }
 
                 MAX_TASKS + 1
@@ -161,34 +155,22 @@ pub fn handle_syscall(
             }
             SysCall::AllocBlocks => {
                 let count = a1;
-                let block = unsafe {
-                    tc.memory_manager
-                        .as_mut()
-                        .unwrap_unchecked()
-                        .alloc_n_blocks(count)
-                };
                 let addr = unsafe {
                     tc.memory_manager
                         .as_mut()
                         .unwrap_unchecked()
-                        .block_to_addr(block)
+                        .alloc_n_blocks(count)
                 };
                 addr
             }
             SysCall::FreeBlocks => {
                 let addr = a1;
                 let count = a2;
-                let block = unsafe {
-                    tc.memory_manager
-                        .as_mut()
-                        .unwrap_unchecked()
-                        .addr_to_block(addr)
-                };
                 unsafe {
                     tc.memory_manager
                         .as_mut()
                         .unwrap_unchecked()
-                        .free_n_blocks(block, count)
+                        .free_n_blocks(addr, count)
                 };
 
                 0
@@ -201,6 +183,14 @@ pub fn handle_syscall(
                         core::slice::from_raw_parts(addr as *const u8, count)
                     });
                 }
+                if tc.use_fb_console {
+                    let mut fbcons = crate::dev::framebuffer::console::FBCONSOLE.lock();
+                    fbcons.printstr(&mut tc, unsafe {
+                        core::str::from_utf8_unchecked(unsafe {
+                            core::slice::from_raw_parts(addr as *const u8, count)
+                        })
+                    });
+                }
                 0
             }
             SysCall::ReadHBD => {
@@ -226,13 +216,47 @@ pub fn handle_syscall(
             }
             SysCall::InitKernel => {
                 tc.init_mem_if_not();
+                {
+                    // sanity check
+                    const FAILURE: &str = "memory manager sanity check failed";
+                    let mem = unsafe {
+                        tc.memory_manager.as_mut().unwrap_unchecked()
+                    };
+                    let addr = mem.alloc_one_block();
+                    let addr2 = mem.alloc_n_blocks(2);
+                    if mem.is_addr_free(addr) || mem.is_addr_free(addr2) || mem.is_addr_free(addr2 + 512) {
+                        let uart = serial_port();
+                        if let Some(uart) = uart {
+                            uart.putstr(FAILURE);
+                        }
+                        rough_panic([';', '-', ';'])
+                    }
+                    mem.free_one_block(addr);
+                    mem.free_n_blocks(addr2, 2);
+
+                    if !(mem.is_addr_free(addr) || mem.is_addr_free(addr2) || mem.is_addr_free(addr2 + 512)) {
+                        let uart = serial_port();
+                        if let Some(uart) = uart {
+                            uart.putstr(FAILURE);
+                        }
+                        rough_panic([';', '-', ';'])
+                    }
+                }
                 crate::dev::probe_devices(&mut tc);
+                if crate::dev::FRAMEBUFFER_ADDR.load(Ordering::Relaxed) != 0 {
+                    tc.use_fb_console = true;
+                    {
+                        let uart = serial_port();
+                        if let Some(uart) = uart {
+                            uart.putstr("using framebuffer console\n");
+                        }
+                    }
+                }
                 0
             }
             SysCall::SendNotification => {
                 let taskid = a1;
                 let addr = a2;
-                let addr_block = unsafe { tc.memory_manager.as_mut().unwrap_unchecked().addr_to_block(addr) };
                 let ci = tc.current;
                 if let Some(Some(task)) = tc.tasks.get_mut(taskid).as_mut() {
                     let waiting = task.wait & TaskWait::WaitForNotification as u32 != 0;
@@ -249,7 +273,7 @@ pub fn handle_syscall(
                             current_task.ackwait[taskid] = 1;
                         }
                     } else {
-                        task.incoming_notifications[ci] = Some(addr_block); // queue it for them
+                        task.incoming_notifications[ci] = Some(addr); // queue it for them
                     }
                     0
                 } else {
@@ -262,15 +286,9 @@ pub fn handle_syscall(
                 suspend = true;
                 if let Some(task) = tc.tasks[ci].as_mut() {
                     // is there already a pending notification?
-                    for (i, block) in task.incoming_notifications.iter_mut().enumerate() {
+                    for (i, addr) in task.incoming_notifications.iter_mut().enumerate() {
-                        if let Some(block) = block.take() {
+                        if let Some(addr) = addr.take() {
                             // yes, there is
-                            let addr = unsafe {
-                                tc.memory_manager
-                                    .as_mut()
-                                    .unwrap_unchecked()
-                                    .block_to_addr(block as usize)
-                            };
                             if let Some(sender_task) = tc.tasks[i].as_mut() {
                                 if sender_task.ackwait[ci] == 3 { // they are waiting for us to ack
                                     sender_task.ackwait[ci] = 0;
@@ -328,6 +346,31 @@ pub fn handle_syscall(
                     0
                 }
             }
+            SysCall::DisableFramebufferConsole => {
+                tc.use_fb_console = false;
+                0
+            }
+            SysCall::EnableFramebufferConsole => {
+                if crate::dev::FRAMEBUFFER_ADDR.load(Ordering::Relaxed) != 0 {
+                    tc.use_fb_console = true;
+                    // clear the screen
+                    let mut fbcons = crate::dev::framebuffer::console::FBCONSOLE.lock();
+                    fbcons.clear_terminal(&mut tc);
+                }
+
+                0
+            }
+            SysCall::FramebufferPointer => {
+                crate::dev::FRAMEBUFFER_ADDR.load(Ordering::Relaxed)
+            }
+            SysCall::FlushFramebufferRect => {
+                let x = a1 as u32;
+                let y = a2 as u32;
+                let w = a3 as u32;
+                let h = a4 as u32;
+                crate::dev::framebuffer_push(&mut tc, x, y, w, h);
+                0
+            }
         },
         suspend,
     )
@@ -345,24 +388,18 @@ pub fn context_switch<'a>(tc: &'a mut TrafficControl, current: Task) -> Option<&
         if want_exit {
             tc.init_mem_if_not();
             let sp = tc.tasks[i].as_ref().map(|v| v.sp).unwrap_or(0);
-            let ddi_start_block = tc.tasks[i].as_ref().map(|v| v.ddi_mem_start_block).unwrap_or(0);
+            let ddi_start_block = tc.tasks[i].as_ref().map(|v| v.ddi_mem_start).unwrap_or(0);
             let ddi_blocks_count = tc.tasks[i].as_ref().map(|v| v.ddi_mem_blocks_count).unwrap_or(0);
             if sp != 0 {
-                let stackblock = unsafe {
-                    tc.memory_manager
-                        .as_mut()
-                        .unwrap_unchecked()
-                        .addr_to_block(sp - BLOCK_SIZE)
-                };
                 unsafe {
                     tc.memory_manager
                         .as_mut()
                         .unwrap_unchecked()
-                        .free_n_blocks(stackblock, 4)
+                        .free_n_blocks(sp - (BLOCK_SIZE * STACK_SIZE_IN_BLOCKS), STACK_SIZE_IN_BLOCKS)
                 };
                 unsafe {
                     tc.memory_manager.as_mut().unwrap_unchecked()
-                        .free_n_blocks(ddi_start_block as usize, ddi_blocks_count as usize)
+                        .free_n_blocks(ddi_start_block, ddi_blocks_count)
                 }
             }
             tc.tasks[i] = None;
@@ -417,6 +454,7 @@ pub struct TrafficControl {
     pub inbuf_read: u8,
     pub inbuf_write: u8,
     pub hung_system: bool,
+    pub use_fb_console: bool,
 }
 
 pub struct Task {
@@ -430,7 +468,7 @@ pub struct Task {
     pub incoming_notifications: [Option<usize>; MAX_TASKS],
     pub ackwait: [u8; MAX_TASKS], // 3 = they have not yet received the notification, 1 = they have received the notification, 0 = we know they received the notification, or don't care
     pub task_wait: u8,
-    pub ddi_mem_start_block: usize,
+    pub ddi_mem_start: usize,
     pub ddi_mem_blocks_count: usize,
     #[cfg(feature = "arch_virt")]
     pub trap_frame: arch::virt::trap::TrapFrame,
@@ -449,6 +487,7 @@ impl TrafficControl {
             inbuf_read: 0,
             inbuf_write: 0,
             hung_system: false,
+            use_fb_console: false,
         }
     }
 

src/uart.rs

@@ -1,5 +1,7 @@
 use core::fmt::Write;
 
+// todo: this should probably be in the dev module
+
 pub trait Serial {
     fn put(&self, c: u8);
     fn putstr(&self, s: &str);

turntable/src/main.rs

@@ -111,14 +111,14 @@ fn lsdir(env: &Environment<'_>) {
             println("unexpected eod");
             break;
         }
-        print(" - ");
+        print("- ");
         liblbos::syscalls::write_terminal(
             &record.name[..record.name.iter().position(|&x| x == 0).unwrap_or(11)],
         );
         if record.record_type == liblbos::fs::RecordType::Directory as u8 {
-            print(" (dir)");
+            print("(dir)");
         } else {
-            print(" (file)");
+            print("(file)");
         }
     }
     print("\n");
@@ -301,7 +301,7 @@ extern "C" fn main() {
     print(VERSION);
     print("\n");
 
-    println("(c) 2025 Real Microsoft, LLC");
+    println("(c) 2025\nReal Microsoft, LLC");
 
     print("> ");
 
@@ -319,20 +319,18 @@ extern "C" fn main() {
                     if *c == 0x7f && cmdbuf_len > 0 {
                         cmdbuf_len -= 1;
                         print("\x08 \x08");
-                    } else {
+                    } else if *c == b'\r' {
+                        execute(unsafe {
+                            core::str::from_utf8_unchecked(&cmdbuf[0..cmdbuf_len])
+                        },
+                                &mut environment);
+                        cmdbuf_len = 0;
+                        print("> ");
+                        break;
+                    } else if !c.is_ascii_control() {
                         cmdbuf[cmdbuf_len] = *c;
                         cmdbuf_len += 1;
-                        if *c == b'\r' {
+                        liblbos::syscalls::write_terminal(&[*c]);
-                            execute(unsafe {
-                                core::str::from_utf8_unchecked(&cmdbuf[0..cmdbuf_len - 1])
-                            },
-                            &mut environment);
-                            cmdbuf_len = 0;
-                            print("> ");
-                            break;
-                        } else {
-                            liblbos::syscalls::write_terminal(&[*c]);
-                        }
                     }
                 }
             }