diff --git a/src/common/profiler.zig b/src/common/profiler.zig
index 0c02857..9b1243d 100644
--- a/src/common/profiler.zig
+++ b/src/common/profiler.zig
@@ -49,7 +49,7 @@ pub const ProfileMark = struct {
         };
     }
 
-    pub fn begin(self: *const Self) !void {
+    pub fn begin(self: *const Self) void {
         const frame = time.getFrameCount();
 
         if (frame != ctx.frame) {
@@ -68,7 +68,7 @@ pub const ProfileMark = struct {
         if (ctx.count < node_limit and ctx.depth < depth_limit) {
             const parent = ctx.current orelse &ctx.root;
 
-            const next = try allocator.create(Node);
+            const next = allocator.create(Node) catch unreachable;
             next.mark = self;
             next.parent = parent;
             next.depth = ctx.depth;
@@ -112,8 +112,8 @@ pub const ProfileMark = struct {
 
 const Testing = struct {
     const pm_slow_func = ProfileMark.init("Test.slow_func");
-    fn slow_func() !void {
-        try pm_slow_func.begin();
+    fn slow_func() void {
+        pm_slow_func.begin();
         defer pm_slow_func.end();
 
         std.time.sleep(100);
@@ -121,7 +121,7 @@ const Testing = struct {
 };
 
 test "profile test" {
-    try Testing.slow_func();
+    Testing.slow_func();
     const fchild = ctx.root.fchild orelse unreachable;
 
     try testing.expectEqual(std.math.Order.lt, fchild.begin.order(fchild.end));
diff --git a/src/main.zig b/src/main.zig
index bf93d2e..27f3904 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -32,7 +32,7 @@ pub fn main() !void {
 
     while (!window.shouldClose()) {
         std.debug.print("hi", .{});
-        renderer.update();
+        try renderer.update();
         try glfw.pollEvents();
     }
 }
diff --git a/src/rendering/vulkan/Command.zig b/src/rendering/vulkan/Command.zig
index 8f4a366..e8752df 100644
--- a/src/rendering/vulkan/Command.zig
+++ b/src/rendering/vulkan/Command.zig
@@ -2,11 +2,13 @@ const assert = @import("std").debug.assert;
 const vk = @import("vulkan");
 
 const settings = @import("settings.zig");
+const Context = @import("Context.zig");
 const Device = @import("device.zig").Device;
 const ProfileMark = @import("../../common/profiler.zig").ProfileMark;
 const Renderer = @import("Renderer.zig");
 const SubmitId = @import("swapchain.zig").SubmitId;
 const Fence = @import("sync.zig").Fence;
+const Semaphore = @import("sync.zig").Semaphore;
 
 const queues = @import("queues.zig");
 
@@ -46,7 +48,7 @@ const read_access: vk.AccessFlags = .{
 
 const pm_init = ProfileMark.init("Command.init");
 pub fn init(device: *const Device, queue: *queues.Queue, id: queues.QueueId) !void {
-    try pm_init.begin();
+    pm_init.begin();
     defer pm_init.end();
 
     assert(queue == queues.get(id));
@@ -70,7 +72,7 @@ pub fn init(device: *const Device, queue: *queues.Queue, id: queues.QueueId) !vo
 
 const pm_deinit = ProfileMark("Command.deinit");
 pub fn deinit(device: *const Device, queue: *const queues.Queue) void {
-    pm_init.begin() catch {};
+    pm_init.begin();
     defer pm_init.end();
 
     for (queue.cmd_fences) |fence| {
@@ -80,18 +82,42 @@ pub fn deinit(device: *const Device, queue: *const queues.Queue) void {
     queue.cmd_pool.deinit(device);
 }
 
+pub fn get(queue_id: queues.QueueId, device: *const Device) !*Buffer {
+    var ctx = Context.context;
+    var cmd = &ctx.cur_cmd_buf[@enumToInt(queue_id)];
+    if (cmd.handle == .null_handle) {
+        try cmd.init(device, queues.get(queue_id));
+    }
+
+    if (!cmd.began) {
+        try device.dispatch.beginCommandBuffer(cmd.handle, &.{
+            .s_type = .command_buffer_begin_info,
+            .flags = .{ .one_time_submit_bit = true },
+            .p_inheritance_info = null,
+        });
+        cmd.began = true;
+        ctx.most_recent_begin = queue_id;
+    }
+
+    return cmd;
+}
+
 pub fn getHeadSubmit(id: queues.QueueId) SubmitId {
     // TODO
     _ = id;
 }
 
-pub const Buffer = packed struct {
+pub fn flush() void {
+    // TODO
+}
+
+pub const Buffer = struct {
     const Self = @This();
 
-    handle: vk.CommandBuffer,
-    fence: vk.Fence,
+    handle: vk.CommandBuffer = .null_handle,
+    fence: Fence,
     id: u32,
-    queue_id: queues.QueueId,
+    queue_id: u4,
     // indicates which types of cmds are legal in this cmdbuf
     gfx: bool,
     comp: bool,
@@ -100,39 +126,36 @@ pub const Buffer = packed struct {
     // cmd state
     began: bool,
     ended: bool,
-    submit: bool,
+    submitted: bool,
     is_render_pass: bool,
     subpass: u8,
     queue_transfer_src: bool,
     queue_transfer_dst: bool,
 
     // XXX: I do not really understand this?
-    pub fn init(self: *Self, queue: queues.Queue) !void {
+    pub fn init(self: *Self, device: *const Device, queue: *queues.Queue) !void {
         const ring_mask: u32 = queue.cmds.len - 1;
         // TODO: decode meaning of SASSERT((NELEM(queue->cmds) & (NELEM(queue->cmds) - 1u)) == 0);
 
         const head_id = queue.head;
         queue.head += 1;
 
-        while (head_id - queue.tail >= queue.cmds.len) {
+        while (head_id - queue.tail >= queue.cmds.len) : (queue.tail += 1) {
             const tail_slot = queue.tail & ring_mask;
             assert(queue.cmd_ids[tail_slot] == queue.tail);
-            const tail_fence = queue.fences[tail_slot];
-            try tail_fence.wait();
-            queue.ids[tail_slot] = 0;
-            queue.tail += 1;
+            const tail_fence = queue.cmd_fences[tail_slot];
+            try tail_fence.wait(device);
+            queue.cmd_ids[tail_slot] = 0;
         }
 
         const head_slot = head_id & ring_mask;
-        assert(!queue.ids[head_slot]);
-        queue.ids[head_slot] = head_id;
+        assert(queue.cmd_ids[head_slot] == 0);
+        queue.cmd_ids[head_slot] = head_id;
         const cmd = queue.cmds[head_slot];
-        const fence = queue.fences[head_slot];
+        const fence = queue.cmd_fences[head_slot];
 
-        assert(fence);
-        assert(cmd);
-        assert(fence.stat() == .signaled);
-        fence.reset();
+        assert((try fence.stat(device)) == .signaled);
+        try fence.reset(device);
 
         self.handle = cmd;
         self.fence = fence;
@@ -143,6 +166,14 @@ pub const Buffer = packed struct {
         self.xfer = queue.xfer;
         self.pres = queue.pres;
     }
+
+    pub fn submit(self: *const Self, wait_sema: Semaphore, wait_mask: vk.PipelineStageFlags, signal_sema: Semaphore) !SubmitId {
+        _ = self;
+        _ = wait_sema;
+        _ = wait_mask;
+        _ = signal_sema;
+        return undefined;
+    }
 };
 
 pub const Pool = struct {
diff --git a/src/rendering/vulkan/Renderer.zig b/src/rendering/vulkan/Renderer.zig
index b2bacd1..dc4f3a3 100644
--- a/src/rendering/vulkan/Renderer.zig
+++ b/src/rendering/vulkan/Renderer.zig
@@ -71,13 +71,13 @@ pub fn init() !Self {
     };
 }
 
-pub fn update(self: Self) void {
+pub fn update(self: *Self) !void {
     // TODO profiling
 
     // base system update
     {
-        try self.swapchain.acquireSync(&self.device);
-        self.swapchain.acquireImage();
+        _ = self.swapchain.acquireSync(&self.device);
+        _ = try self.swapchain.acquireImage(&self.device);
         memory.update();
     }
 
@@ -98,7 +98,8 @@ pub fn update(self: Self) void {
     //self.main_pass.execute();
 
     // present phase
-    self.swapchain.submit(Command.get());
+    // currently only graphics queue
+    try self.swapchain.submit(try Command.get(.graphics, &self.device), &self.device);
 
     // background work
     {
diff --git a/src/rendering/vulkan/image.zig b/src/rendering/vulkan/image.zig
index 281323b..f303ab8 100644
--- a/src/rendering/vulkan/image.zig
+++ b/src/rendering/vulkan/image.zig
@@ -10,7 +10,7 @@ const settings = @import("settings.zig");
 const memory = @import("memory.zig");
 const Swapchain = @import("swapchain.zig").Swapchain;
 
-pub const Image = packed struct {
+pub const Image = struct {
     const Self = @This();
 
     state: ImageState,
@@ -80,13 +80,21 @@ pub const Image = packed struct {
     }
 };
 
-const ImageState = packed struct {
+const ImageState = struct {
+    const Self = @This();
+
     owner: queues.QueueId,
     cmd_id: i32,
     stage: vk.PipelineStageFlags,
     access: vk.AccessFlags,
     layout: vk.ImageLayout,
     substates: [*]SubImageState,
+
+    pub fn presentSrc(self: *Self, command: *const Command.Buffer) !void {
+        // TODO
+        _ = self;
+        _ = command;
+    }
 };
 
 const ImageSet = struct {
diff --git a/src/rendering/vulkan/memory.zig b/src/rendering/vulkan/memory.zig
index 69fbccd..2eee51c 100644
--- a/src/rendering/vulkan/memory.zig
+++ b/src/rendering/vulkan/memory.zig
@@ -33,9 +33,11 @@ pub fn finalize(device: *const Device) !void {
     }
 }
 
+pub fn update() void {}
+
 const pm_imgnew = profiler.ProfileMark.init("memory.imageNew");
 pub fn imageNew(img: *Image, info: *const vk.ImageCreateInfo, mem_usage: vma.MemoryUsage) !void {
-    try pm_imgnew.begin();
+    pm_imgnew.begin();
     defer pm_imgnew.end();
 
     // memset needed?
@@ -70,7 +72,7 @@ pub fn imageNew(img: *Image, info: *const vk.ImageCreateInfo, mem_usage: vma.Mem
 
 const pm_imagedel = profiler.ProfileMark.init("memory.imageDel");
 pub fn imageDel(img: *const Image, device: *const Device) void {
-    pm_imagedel.begin() catch {};
+    pm_imagedel.begin();
     defer pm_imagedel.end();
 
     device.dispatch.destroyImageView(device.handle, img.view, null);
diff --git a/src/rendering/vulkan/queues.zig b/src/rendering/vulkan/queues.zig
index 8a06b0a..c85c7df 100644
--- a/src/rendering/vulkan/queues.zig
+++ b/src/rendering/vulkan/queues.zig
@@ -268,7 +268,7 @@ pub const Queue = struct {
     index: QueueId = 0,
     access_mask: vk.AccessFlags = .{},
     stage_mask: vk.PipelineStageFlags = .{},
-    queueId: u4 = 0,
+    queue_id: u4 = 0,
     gfx: bool = false,
     comp: bool = false,
     xfer: bool = false,
diff --git a/src/rendering/vulkan/render_pass.zig b/src/rendering/vulkan/render_pass.zig
index 8e74081..04fa9ed 100644
--- a/src/rendering/vulkan/render_pass.zig
+++ b/src/rendering/vulkan/render_pass.zig
@@ -13,7 +13,7 @@ const s_cache = std.HashMap(Description, vk.RenderPass).init(allocator);
 
 const pm_get = profiler.ProfileMark.init("renderpass.get");
 pub fn get(desc: *const Description) !vk.RenderPass {
-    try pm_get.begin();
+    pm_get.begin();
     defer pm_get.end();
 
     const result = try s_cache.getOrPut(desc);
diff --git a/src/rendering/vulkan/swapchain.zig b/src/rendering/vulkan/swapchain.zig
index 53fadcc..95ed967 100644
--- a/src/rendering/vulkan/swapchain.zig
+++ b/src/rendering/vulkan/swapchain.zig
@@ -1,6 +1,7 @@
 const std = @import("std");
 const vk = @import("vulkan");
 const math = @import("std").math;
+const Command = @import("Command.zig");
 const profiler = @import("../../common/profiler.zig");
 const settings = @import("settings.zig");
 const Instance = @import("instance.zig").Instance;
@@ -121,7 +122,7 @@ pub const SubmitId = packed struct {
 
     const pm_wait = profiler.ProfileMark.init("swapchain.SubmitId.wait");
     pub fn wait(self: *const SubmitId, device: *const Device) void {
-        pm_wait.begin() catch {};
+        pm_wait.begin();
         defer pm_wait.end();
 
         std.debug.assert(self.valid);
@@ -234,17 +235,19 @@ pub const Swapchain = struct {
             .length = img_count,
         };
 
+        const color_format = format.format;
+
         for (images) |img, i| {
-            try Image.import(&self.images[i], device, &.{
+            try self.images[i].import(device, &.{
                 .s_type = .image_create_info,
                 .flags = .{},
                 .image_type = .@"2d",
-                .format = self.color_format,
                 .extent = .{
                     .width = ext.width,
                     .height = ext.height,
                     .depth = 1,
                 },
+                .format = color_format,
                 .mip_levels = 1,
                 .array_layers = 1,
                 .samples = .{ .@"1_bit" = true },
@@ -281,18 +284,67 @@ pub const Swapchain = struct {
         }
     }
 
-    const pm_acquiresync = profiler.ProfileMark.init("Swapchain.acquireSync");
-    pub fn acquireSync(self: *Self, device: *const Device) !usize {
-        try pm_acquiresync.begin();
+    const pm_acquiresync = profiler.ProfileMark.init("swapchain.Swapchain.acquireSync");
+    pub fn acquireSync(self: *Self, device: *const Device) usize {
+        pm_acquiresync.begin();
         defer pm_acquiresync.end();
 
         const sync_index = (self.sync_index + 1) % self.sync_submits.len;
-        const submit = self.sync_submits[sync_index];
-        if (submit.valid) {
-            submit.wait(device);
+        const sub = self.sync_submits[sync_index];
+        if (sub.valid) {
+            sub.wait(device);
         }
 
         self.sync_index = sync_index;
         return sync_index;
     }
+
+    const pm_acquireimage = profiler.ProfileMark.init("swapchain.Swapchain.acquireImage");
+    pub fn acquireImage(self: *Self, device: *const Device) !usize {
+        pm_acquireimage.begin();
+        defer pm_acquireimage.end();
+
+        const timeout = std.math.maxInt(u64);
+        const result = try device.dispatch.acquireNextImageKHR(device.handle, self.handle, timeout, self.available_semas[self.sync_index].handle, .null_handle);
+        std.debug.assert(result.image_index < self.length);
+        const sub = self.image_submits[result.image_index];
+        if (sub.valid) {
+            sub.wait(device);
+        }
+
+        self.image_index = result.image_index;
+        return result.image_index;
+    }
+
+    const pm_submit = profiler.ProfileMark.init("swapchain.Swapchain.submit");
+    pub fn submit(self: *Self, command: *const Command.Buffer, device: *const Device) !void {
+        pm_submit.begin();
+        defer pm_submit.end();
+
+        const image_index = self.image_index;
+        const sync_index = self.sync_index;
+        {
+            const backbuf = getBackBuffer();
+            const prev_use = backbuf.state.stage;
+            try backbuf.state.presentSrc(command);
+
+            const submit_id = try command.submit(self.available_semas[sync_index], prev_use, self.rendered_semas[sync_index]);
+            self.sync_submits[sync_index] = submit_id;
+            self.image_submits[image_index] = submit_id;
+        }
+
+        {
+            var queue = queues.get(.graphics);
+            if (!queue.pres) {
+                queue = queues.get(.present);
+            }
+
+            _ = try device.dispatch.queuePresentKHR(queue.handle, &.{ .s_type = .present_info_khr, .wait_semaphore_count = 1, .p_wait_semaphores = @ptrCast([*]const vk.Semaphore, &self.rendered_semas[sync_index]), .swapchain_count = 1, .p_swapchains = @ptrCast([*]const vk.SwapchainKHR, &self.handle), .p_results = null, .p_image_indices = @ptrCast([*]const u32, &self.image_index) });
+        }
+    }
+
+    pub fn getBackBuffer() *Image {
+        // TODO
+        return undefined;
+    }
 };
diff --git a/src/rendering/vulkan/sync.zig b/src/rendering/vulkan/sync.zig
index 6e3a8af..9571d87 100644
--- a/src/rendering/vulkan/sync.zig
+++ b/src/rendering/vulkan/sync.zig
@@ -52,7 +52,7 @@ pub const Fence = struct {
     }
 
     pub fn reset(self: *const Self, device: *const Device) !void {
-        try device.dispatch.resetFences(device.handle, 1, &self.handle);
+        try device.dispatch.resetFences(device.handle, 1, @ptrCast([*]const vk.Fence, &self.handle));
     }
 
     pub fn wait(self: *const Self, device: *const Device) !void {