refactor(userspace): split syscall/fat16/ext4 by concern; trim comments

crates/drivers/block/virtio/src/lib.rs

@@ -29,9 +29,8 @@ pub struct VirtioBlockDevice {
 }
 
 impl VirtioBlockDevice {
-    /// Takes over the block device whose MMIO region `mmio` names: maps
-    /// it, allocates the queue and request buffers, and resets the device
-    /// onto them. `None` if any step fails or it is not a block device.
+    /// Takes over the virtio block device behind `mmio`. `None` if it is
+    /// not one or any step fails.
     pub fn new(mmio: types::bounded::CapSlot) -> Option<Self> {
         libkos::device::map_mmio(mmio, MMIO_BASE).ok()?;
         let regs = UserMmio;

crates/drivers/framebuffer/virtio/src/lib.rs

@@ -37,10 +37,8 @@ pub struct VirtioFramebuffer {
 }
 
 impl VirtioFramebuffer {
-    /// Takes over the GPU whose MMIO region `mmio` names: maps it, sets up
-    /// the control queue and command buffer, asks for the display size,
-    /// allocates a framebuffer and makes it the scanout. `None` if it is
-    /// not a virtio GPU or any step fails.
+    /// Takes over the virtio GPU behind `mmio` and makes a framebuffer its
+    /// scanout. `None` if it is not a GPU or any step fails.
     pub fn try_new(mmio: types::bounded::CapSlot) -> Option<Self> {
         libkos::device::map_mmio(mmio, GPU_MMIO_VA).ok()?;
         let regs = GpuMmio;

crates/drivers/input/virtio/src/lib.rs

@@ -31,10 +31,8 @@ pub struct VirtioInputDevice {
 }
 
 impl VirtioInputDevice {
-    /// Takes over the input device whose MMIO region `mmio` names: maps it,
-    /// allocates the queue and event buffers, resets the device onto them
-    /// and hands it every buffer. `None` if it is not a virtio input
-    /// device or a step fails.
+    /// Takes over the virtio input device behind `mmio`. `None` if it is
+    /// not one or any step fails.
     pub fn try_new(mmio: types::bounded::CapSlot) -> Option<Self> {
         libkos::device::map_mmio(mmio, INPUT_MMIO_VA).ok()?;
         let regs = MmioInput;