From 020a6c7d60124a5320c856b213ab38ad40239232 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Gr=C3=A9goire?= <loic@gregoire.dev>
Date: Sat, 27 Jun 2026 16:29:55 -0400
Subject: [PATCH] pl: add debug_read

---
 src/platform/pc/impl.zig | 7 +++++++
 src/platform/root.zig    | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/src/platform/pc/impl.zig b/src/platform/pc/impl.zig
index f27381c..bac6276 100644
--- a/src/platform/pc/impl.zig
+++ b/src/platform/pc/impl.zig
@@ -102,6 +102,13 @@ pub fn debug_write(c: u8) void {
     com1_write(c);
 }
 
+pub fn debug_read() u8 {
+    while ((amd64.inb(com1 + 0x5) & 0x01) == 0) {
+        std.atomic.spinLoopHint();
+    }
+    return amd64.inb(com1);
+}
+
 pub fn arm_timer(deadline: r.Nanoseconds) void {
     apic.arm_timer(deadline);
 }
diff --git a/src/platform/root.zig b/src/platform/root.zig
index bdc5947..7f20079 100644
--- a/src/platform/root.zig
+++ b/src/platform/root.zig
@@ -27,6 +27,11 @@ pub inline fn debug_write(c: u8) void {
     return impl.debug_write(c);
 }
 
+/// Read a single character from the debug console.
+pub inline fn debug_read() u8 {
+    return impl.debug_read();
+}
+
 /// Arm a one-shot timer to fire in `ns` nanoseconds.
 pub inline fn arm_timer(ns: u64) void {
     return impl.arm_timer(ns);