sylveos

commit 1b56a12cf8851ca6118061624edd5fcd00754674
parent c8b11c0d45fd9d0a3b58e2da319595c2cbef619b
Author: Sylvia Ivory <git@sivory.net>
Date:   Tue, 24 Feb 2026 17:36:29 -0800

Unify interrupt stacks

Diffstat:
M
pi/interrupts.zig
 | 
27
+++++++++++----------------

1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/pi/interrupts.zig b/pi/interrupts.zig
@@ -171,25 +171,22 @@ inline fn setup_reg(pc: u32, gp: *const [13]u32) Registers {
 }
 
 // I still hate this
-const stack_size = 256; // 1kb stacks
+const stack_size = 256 * 16; // 16kb stacks
+pub export var exception_stack: [stack_size]usize align(8) = undefined;
 
 // Things were already cooked
-pub export var reset_stack: [8]usize align(8) = undefined;
 export fn reset_stub(pc: u32, gp: *const [13]u32) void {
     reset_handler(setup_reg(pc, gp));
 }
 
-pub export var undef_stack: [stack_size]usize align(8) = undefined;
 export fn undefined_instruction_stub(pc: u32, gp: *const [13]u32) void {
     undefined_instruction_handler(setup_reg(pc, gp));
 }
 
-pub export var svc_stack: [stack_size]usize align(8) = undefined;
 export fn software_interrupt_stub(pc: u32, gp: *const [13]u32) void {
     software_interrupt_handler(setup_reg(pc, gp));
 }
 
-pub export var abort_stack: [stack_size]usize align(8) = undefined;
 export fn prefetch_abort_stub(pc: u32, gp: *const [13]u32) void {
     prefetch_abort_handler(setup_reg(pc, gp));
 }
@@ -198,24 +195,22 @@ export fn data_abort_stub(pc: u32, gp: *const [13]u32) void {
     data_abort_handler(setup_reg(pc, gp));
 }
 
-pub export var irq_stack: [stack_size]usize align(8) = undefined;
 export fn interrupt_stub(pc: u32, gp: *const [13]u32) void {
     interrupt_handler(setup_reg(pc, gp));
 }
 
 // TODO;
-pub export var fiq_stack: [stack_size]usize align(8) = undefined;
 export fn fast_interrupt_stub(pc: u32, reg: *Registers) void {
     _ = pc;
     _ = reg;
 }
 
-fn create_trampoline(name: []const u8, offset: []const u8, ret: []const u8, stack: []const u8) []const u8 {
+fn create_trampoline(name: []const u8, offset: []const u8, ret: []const u8) []const u8 {
     return "" ++
         ".global " ++ name ++ "\n" ++
         ".type " ++ name ++ ", %function\n" ++
         name ++ ":\n" ++
-        "  ldr sp, =" ++ stack ++ "\n" ++
+        "  ldr sp, =exception_stack\n" ++
         "  push {r0-r12, lr}\n" ++
         "  sub lr, lr, #" ++ offset ++ "\n" ++
         "  mov r0, lr\n" ++
@@ -225,13 +220,13 @@ fn create_trampoline(name: []const u8, offset: []const u8, ret: []const u8, stac
 }
 
 comptime {
-    asm (create_trampoline("reset", "4", "", "reset_stack")); // doesn't matter
-    asm (create_trampoline("undefined_instruction", "4", "movs pc, lr", "undef_stack"));
-    asm (create_trampoline("software_interrupt", "4", "movs pc, lr", "svc_stack"));
-    asm (create_trampoline("prefetch_abort", "4", "subs pc, lr, #4", "abort_stack"));
-    asm (create_trampoline("data_abort", "8", "subs pc, lr, #8", "abort_stack"));
-    asm (create_trampoline("interrupt", "4", "subs pc, lr, #4", "irq_stack"));
-    asm (create_trampoline("fast_interrupt", "4", "subs pc, lr, #4", "fiq_stack"));
+    asm (create_trampoline("reset", "4", "")); // doesn't matter
+    asm (create_trampoline("undefined_instruction", "4", "movs pc, lr"));
+    asm (create_trampoline("software_interrupt", "4", "movs pc, lr"));
+    asm (create_trampoline("prefetch_abort", "4", "subs pc, lr, #4"));
+    asm (create_trampoline("data_abort", "8", "subs pc, lr, #8"));
+    asm (create_trampoline("interrupt", "4", "subs pc, lr, #4"));
+    asm (create_trampoline("fast_interrupt", "4", "subs pc, lr, #4"));
 }
 extern fn reset() void;
 extern fn undefined_instruction() void;