sylveos

commit 1be28b565b3da52c64f87f313806d554d1f39afe
parent 09706d2cb7559581198b024d80e25c83fec32ee2
Author: Sylvia Ivory <git@sivory.net>
Date:   Tue, 20 Jan 2026 18:30:06 -0800

Add more proper panic handler

Diffstat:
M
src/devices/mini-uart.zig
 | 
10
+++++++---
M
src/main.zig
 | 
4
+++-
M
src/root.zig
 | 
12
+++++++++++-

3 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/src/devices/mini-uart.zig b/src/devices/mini-uart.zig
@@ -34,10 +34,10 @@ const RxPin = enum(u8) {
     Gpio37 = 37,
 };
 
-// var is_initialized = false;
+var initialized = false;
 
 pub fn initialize(baud: u32, tx_pin: TxPin, rx_pin: RxPin) Error!void {
-    // if (is_initialized) return Error.AlreadyInitialized;
+    if (initialized) return Error.AlreadyInitialized;
 
     // Set GPIO pins first (as specified by manual)
     // Page 102 specifies which alt mode
@@ -100,7 +100,11 @@ pub fn initialize(baud: u32, tx_pin: TxPin, rx_pin: RxPin) Error!void {
     mem.put_u32(@ptrFromInt(AUX_MU_CNTL_REG), 0x3);
     // mem.put_u32(@ptrFromInt(AUX_MU_CNTL_REG), 2);
 
-    // is_initialized = true;
+    initialized = true;
+}
+
+pub fn is_initialized() bool {
+    return initialized;
 }
 
 fn can_write() bool {
diff --git a/src/main.zig b/src/main.zig
@@ -2,5 +2,7 @@ const uart = @import("devices/mini-uart.zig");
 
 pub fn main() !void {
     try uart.initialize(115200, .Gpio14, .Gpio15);
-    uart.write_slice("Hello, World!");
+    uart.write_slice("Hello, World!\n");
+
+    @panic("oops");
 }
diff --git a/src/root.zig b/src/root.zig
@@ -1,4 +1,6 @@
 const std = @import("std");
+
+const uart = @import("devices/mini-uart.zig");
 const fake_main = @import("main.zig").main;
 
 export fn abort() noreturn {
@@ -11,8 +13,16 @@ pub export fn kmain() void {
 }
 
 fn panic_handler(msg: []const u8, trace_addr: ?usize) noreturn {
-    _ = msg;
+    @branchHint(.cold);
     _ = trace_addr;
+
+    if (uart.is_initialized()) {
+        uart.write_slice("Panic: ");
+        uart.write_slice(msg);
+        uart.write_byte('\n');
+    }
+
+    // TODO; proper abort
     abort();
 }