From e8dfcfc62dc98c42c636bc8106bd0d681b1b3f91 Mon Sep 17 00:00:00 2001
From: em-dash <33614480+em-dash@users.noreply.github.com>
Date: Sat, 18 Jul 2026 11:25:56 +1000
Subject: [PATCH 1/2] update to 0.16.0

---
 build.zig      | 2 +-
 src/kernel.zig | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/build.zig b/build.zig
index 9f932a3..de72322 100644
--- a/build.zig
+++ b/build.zig
@@ -20,7 +20,7 @@ pub fn build(b: *std.Build) anyerror!void {
 
     kernel.setLinkerScript(b.path("src/linker.lds"));
 
-    kernel.addCSourceFiles(.{
+    kernel.root_module.addCSourceFiles(.{
         .files = &.{"src/boot.S"},
         .flags = &.{ "-x", "assembler-with-cpp" },
     });
diff --git a/src/kernel.zig b/src/kernel.zig
index f52f1ed..203f7cd 100644
--- a/src/kernel.zig
+++ b/src/kernel.zig
@@ -3,7 +3,7 @@ const uart = @import("uart.zig");
 
 // Here we set up a printf-like writer from the standard library by providing
 // a way to output via the UART.
-pub fn drainUart(w: *std.io.Writer, data: []const []const u8, splat: usize) !usize {
+pub fn drainUart(w: *std.Io.Writer, data: []const []const u8, splat: usize) !usize {
     _ = try uartPutStr(w.buffer);
     w.end = 0;
     var bytes_written: usize = 0;
@@ -18,7 +18,7 @@ pub fn drainUart(w: *std.io.Writer, data: []const []const u8, splat: usize) !usi
     return bytes_written;
 }
 
-var uart_writer = std.io.Writer{
+var uart_writer = std.Io.Writer{
     .buffer = &[_]u8{} ** 1024,
     .end = 0,
     .vtable = &.{ .drain = drainUart },

From 59cfb7d0b1bc6519eb2baa2fe0460ac8a9ebd178 Mon Sep 17 00:00:00 2001
From: em-dash <33614480+em-dash@users.noreply.github.com>
Date: Sat, 18 Jul 2026 11:32:27 +1000
Subject: [PATCH 2/2] fix writer drain function and buffer

---
 src/kernel.zig | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/kernel.zig b/src/kernel.zig
index 203f7cd..0da1f08 100644
--- a/src/kernel.zig
+++ b/src/kernel.zig
@@ -4,22 +4,21 @@ const uart = @import("uart.zig");
 // Here we set up a printf-like writer from the standard library by providing
 // a way to output via the UART.
 pub fn drainUart(w: *std.Io.Writer, data: []const []const u8, splat: usize) !usize {
-    _ = try uartPutStr(w.buffer);
+    _ = try uartPutStr(w.buffer[0..w.end]);
     w.end = 0;
     var bytes_written: usize = 0;
     for (data[0 .. data.len - 1]) |slice| {
         bytes_written += try uartPutStr(slice);
     }
-    if (splat == 0 or data.len < 1) return bytes_written;
-    const last_data = data[data.len - 1];
     for (0..splat) |_| {
-        bytes_written += try uartPutStr(last_data);
+        bytes_written += try uartPutStr(data[data.len - 1]);
     }
     return bytes_written;
 }
 
+var uart_writer_buffer: [1024]u8 = undefined;
 var uart_writer = std.Io.Writer{
-    .buffer = &[_]u8{} ** 1024,
+    .buffer = &uart_writer_buffer,
     .end = 0,
     .vtable = &.{ .drain = drainUart },
 };
@@ -33,6 +32,7 @@ fn uartPutStr(str: []const u8) !usize {
 
 pub fn println(comptime fmt: []const u8, args: anytype) void {
     uart_writer.print(fmt ++ "\n", args) catch {};
+    uart_writer.flush() catch {};
 }
 
 // This the trap/exception entrypoint, this will be invoked any time