Stuff with syscall API

libgila/src/syscall/mod.rs

@@ -1,7 +1,13 @@
+use core::{error::Error, num::ParseIntError};
+
 use num_derive::FromPrimitive;
 use num_traits::FromPrimitive;
 
 use crate::arch;
+
+pub struct SyscallError {
+}
+
 #[repr(u32)]
 #[derive(FromPrimitive, Debug)]
 pub enum Syscall {
@@ -15,11 +21,17 @@ pub enum Syscall {
     Pid = 1,
     /// Send a message to another process.
     Message = 2,
+    /// Map new pages.
     MemMap = 3,
+    /// Unmap existing pages.
     MemUnmap = 4,
+    /// Resolve a service name to a process.
     Resolve = 5,
+    /// Spawn a new process.
     Spawn = 6,
+    /// Access information about the kernel versioning.
     Version = 7,
+    /// Yield the remainder of quantum to another process.
     Yield = 8,
 }
 
@@ -27,23 +39,33 @@ pub enum Syscall {
 #[derive(FromPrimitive, Debug)]
 pub enum SyscallStatus {
     /// Syscall completed without any issues.
-    Success,
+    Success = 0,
     /// Issued a system call with the wrong call ID.
-    NoSuchCall,
-    NoSuchProcess,
-    NoSuchService,
-    SecurityFailure,
-    OutOfMemory,
-    Aborted,
-    Unspecified,
-    Unknown,
-    Unimplemented,
-    InvalidPage,
+    NoSuchCall = 1,
+    /// Issued a system call referencing a nonexistent process.
+    NoSuchProcess = 2,
+    /// Issued a system call referencing a nonexistent service name.
+    NoSuchService = 3,
+    /// System call was prevented by some security policy.
+    SecurityFailure = 4,
+    /// Could not allocate any more pages since there are none left.
+    OutOfMemory = 5,
+    /// System call failed to complete in constant time.
+    Aborted = 6,
+    /// Attempted to issue an unimplemented system call.
+    Unimplemented = 7,
+    /// Issued a system call with a malformed parameter.
+    InvalidParameter = 8,
 }
 
-impl From<u64> for SyscallStatus {
-    fn from(value: u64) -> Self {
-        SyscallStatus::from_u64(value).unwrap_or(Self::Unknown)
+impl TryFrom<u64> for SyscallStatus {
+    type Error = SyscallError;
+    fn try_from(value: u64) -> Result<Self, Self::Error> {
+        if let Some(status) = SyscallStatus::from_u64(value) {
+            Ok(status)
+        } else {
+            Err(SyscallError {})
+        }
     }
 }