Add stvec setter by transitioning to csrw function creation function (less duplicated code)

1 files changed, 20 insertions, 7 deletions

diff --git a/src/instructions.zig b/src/instructions.zig
index 6e4fe00..831a62c 100644
--- a/src/instructions.zig
+++ b/src/instructions.zig
@@ -2,6 +2,9 @@
 //
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
+const std = @import("std");
+
+const interrupts = @import("interrupts.zig");
 const paging = @import("paging.zig");
 
 pub const SbiRet = struct {
@@ -43,12 +46,22 @@ pub inline fn setStackPointer(sp: usize) void {
     );
 }
 
-pub fn setSatp(satp: paging.Satp) void {
-    const value: usize = @bitCast(satp);
+pub const setSatp = setCsrFn(paging.Satp, "satp").?;
+pub const setSupervisorTrapVector = setCsrFn(interrupts.SupervisorTrapVector, "stvec").?;
 
-    asm volatile (
-        \\ csrw satp, %[value]
-        :
-        : [value] "r" (value),
-    );
+fn setCsrFn(comptime T: type, csr: []const u8) ?fn (T) void {
+    if (csr.len > 5) return null;
+
+    return struct {
+        fn setCsr(value: T) void {
+            const bits: usize = @bitCast(value);
+
+            comptime var buf = [_]u8{0} ** 20;
+
+            asm volatile (std.fmt.bufPrint(buf[0..], "csrw {s}, %[bits]", .{csr}) catch unreachable
+                :
+                : [bits] "r" (bits),
+            );
+        }
+    }.setCsr;
 }