nvmed: Verify correct memory space

nvmed/src/main.rs

@@ -11,6 +11,8 @@ use std::io::{Read, Write};
 use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
 use syscall::{EVENT_READ, MAP_WRITE, Event, Packet, Result, Scheme};
 
+use self::nvme::Nvme;
+
 mod nvme;
 
 fn create_scheme_fallback<'a>(name: &'a str, fallback: &'a str) -> Result<(&'a str, RawFd)> {
@@ -40,6 +42,8 @@ fn main() {
     if unsafe { syscall::clone(0).unwrap() } == 0 {
         let address = unsafe { syscall::physmap(bar, 4096, MAP_WRITE).expect("nvmed: failed to map address") };
         {
+            let mut nvme = Nvme::new(address);
+            nvme.init();
             /*
             let (_scheme_name, socket_fd) = create_scheme_fallback("disk", &name).expect("nvmed: failed to create disk scheme");
             let mut socket = unsafe { File::from_raw_fd(socket_fd) };

nvmed/src/nvme.rs

@@ -1,8 +1,13 @@
 use syscall::io::{Io, Mmio};
 
+#[repr(packed)]
 pub struct NvmeCmd {
-    /// Command dword 0
-    cdw0: u32,
+    /// Opcode
+    opcode: u8,
+    /// Flags
+    flags: u8,
+    /// Command ID
+    cid: u16,
     /// Namespace identifier
     nsid: u32,
     /// Reserved
@@ -28,7 +33,9 @@ pub struct NvmeCmd {
 impl NvmeCmd {
     pub fn read(cid: u16, lba: u64, count: u16, dst: u64) -> Self {
         NvmeCmd {
-            cdw0: (cid as u32) << 16 | 1 << 14 | 2,
+            opcode: 2,
+            flags: 1 << 6,
+            cid: cid,
             nsid: 0xFFFFFFFF,
             _rsvd: 0,
             mptr: 0,
@@ -44,7 +51,9 @@ impl NvmeCmd {
 
     pub fn write(cid: u16, lba: u64, count: u16, src: u64) -> Self {
         NvmeCmd {
-            cdw0: (cid as u32) << 16 | 1 << 14 | 1,
+            opcode: 1,
+            flags: 1 << 6,
+            cid: cid,
             nsid: 0xFFFFFFFF,
             _rsvd: 0,
             mptr: 0,
@@ -88,3 +97,20 @@ pub struct NvmeRegs {
     /// Controller memory buffer size
     cmbsz: Mmio<u32>,
 }
+
+pub struct Nvme {
+    regs: &'static mut NvmeRegs
+}
+
+impl Nvme {
+    pub fn new(address: usize) -> Self {
+        Nvme {
+            regs: unsafe { &mut *(address as *mut NvmeRegs) }
+        }
+    }
+
+    pub fn init(&mut self) {
+        println!("  - CAPS: {:X}", self.regs.cap.read());
+        println!("  - VS: {:X}", self.regs.vs.read());
+    }
+}