process: Use simple rotating scheduler

1 files changed, 10 insertions, 0 deletions

diff --git a/src/interrupts.zig b/src/interrupts.zig
index a2233aa..de03337 100644
--- a/src/interrupts.zig
+++ b/src/interrupts.zig
@@ -7,6 +7,7 @@ const std = @import("std");
 const debug_console = @import("sbi/debug_console.zig");
 const instructions = @import("instructions.zig");
 const plic = @import("plic.zig");
+const process = @import("process.zig");
 const syscall = @import("syscall.zig");
 const time = @import("sbi/time.zig");
 const trap = @import("trap.zig");
@@ -101,6 +102,7 @@ export fn handleTrap(epc: usize, tval: usize, cause_bits: usize, hart_id: usize,
             .supervisor_software => w.print("Hart {d}: Software interrupt\r\n", .{hart_id}) catch while (true) {},
             .supervisor_timer => {
                 time.interruptInSeconds(null, 1) catch while (true) {};
+                schedule() catch while (true) {};
             },
             .supervisor_external => {
                 const context: u14 = @intCast(2 * hart_id + 1);
@@ -266,6 +268,14 @@ export fn supervisorTrapVector() align(4) callconv(.Naked) noreturn {
     );
 }
 
+fn schedule() noreturn {
+    if (process.next()) |next| {
+        process.switchTo(next);
+    }
+
+    while (true) asm volatile ("wfi");
+}
+
 pub fn init() void {
     trap_frame = .{
         .general_purpose_registers = [_]usize{0} ** 32,