syscall: Add stubs for VFS interaction

1 files changed, 59 insertions, 0 deletions

diff --git a/src/lib/syscall.zig b/src/lib/syscall.zig
index 642d0c4..0e0c1f1 100644
--- a/src/lib/syscall.zig
+++ b/src/lib/syscall.zig
@@ -10,13 +10,32 @@ pub const Error = error{
     UnknownSyscall,
 };
 
+pub const Status = enum(usize) {
+    success,
+};
+
+pub const ReadFn = *const fn (context: u16, buffer: []u8) Result(usize);
+pub const WriteFn = *const fn (context: u16, bytes: []const u8) Result(usize);
+
+pub fn Result(comptime T: type) type {
+    return struct {
+        status: Status,
+        value: T,
+    };
+}
+
 pub fn handle(trap_frame: *const trap.Frame) !void {
     switch (trap_frame.general_purpose_registers[17]) {
         100000 => uprint(trap_frame),
+        100001 => open(trap_frame),
+        100002 => close(trap_frame),
+        100003 => provide(trap_frame),
+        100004 => remove(trap_frame),
         else => return Error.UnknownSyscall,
     }
 }
 
+// uprint(str_addr: usize, len: usize) void
 fn uprint(trap_frame: *const trap.Frame) void {
     const procmem: *paging.Table = @ptrFromInt(instructions.satp.read().ppn << 12);
 
@@ -28,3 +47,43 @@ fn uprint(trap_frame: *const trap.Frame) void {
     const w = @import("Console.zig").autoChoose().?.writer();
     w.print("User message: {s}\r\n", .{str}) catch unreachable;
 }
+
+// open(path: *const [:0]u8) Result(usize)
+fn open(trap_frame: *const trap.Frame) void {
+    const path: *const [:0]u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
+
+    _ = path;
+    unreachable;
+}
+
+// close(rd: usize) void
+fn close(trap_frame: *const trap.Frame) void {
+    const rd = trap_frame.general_purpose_registers[10];
+
+    _ = rd;
+    unreachable;
+}
+
+// provide(
+//     path: *const [:0]u8,
+//     readFn: fn (context: u16, buffer: []u8) Result(usize),
+//     writeFn: fn (context: u16, bytes: []const u8) Result(usize)
+// ) Result(usize)
+fn provide(trap_frame: *const trap.Frame) void {
+    const path: *const [:0]u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
+    const readFn: ReadFn = @ptrFromInt(trap_frame.general_purpose_registers[11]);
+    const writeFn: WriteFn = @ptrFromInt(trap_frame.general_purpose_registers[12]);
+
+    _ = path;
+    _ = readFn;
+    _ = writeFn;
+    unreachable;
+}
+
+// remove(path: *const [:0]u8) Result(usize)
+fn remove(trap_frame: *const trap.Frame) void {
+    const path: *const [:0]u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
+
+    _ = path;
+    unreachable;
+}