From 1329d1db52ede274d63b56a7aa37dd25c833ec67 Mon Sep 17 00:00:00 2001
From: Nathan Lee <me@nwlee.tech>
Date: Wed, 29 Jul 2026 19:11:29 -0500
Subject: create basic MMIO handler for console

---
 console/module_main.c | 38 ++++++++++++++++++++++++++++++++++++--
 include/log.h         |  2 ++
 include/mmio.h        |  8 ++++++++
 kernel/log.c          |  9 +++++++++
 4 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 include/mmio.h

diff --git a/console/module_main.c b/console/module_main.c
index 521aebc..8aeac9f 100644
--- a/console/module_main.c
+++ b/console/module_main.c
@@ -1,10 +1,44 @@
+#include <log.h>
+#include <mmio.h>
+
 #ifndef __KERNEL_MODULE__
 #define __KERNEL_MODULE__
 #endif
 
-int test_module_init(void) {
+extern console_callback_t callback;
+
+struct console_device_meta {
+    void *register_controller;
+    void *data_start;
+    void *data_end;
+};
+
+const char compatible[] __attribute__((section(".compatible"))) = "unix,soc-tty";
+size_t pos = 0;
+struct console_device_meta dev_meta = { NULL, NULL, NULL };
+
+__attribute__((visibility("hidden"))) void console_put_char(char c) {
+    ((char *)dev_meta.data_start)[pos++] = c;
+
+    if (c == '\n') {
+        *((uint8_t *)dev_meta.register_controller) = 1;
+        pos = 0;
+    }
+    return;
+}
+
+
+int __attribute__((section(".module_init"))) module_init(struct mmio_device_meta *meta) {
+    callback = console_put_char;
+
+    dev_meta.register_controller = meta->start;
+    dev_meta.data_start = (void *)((uint8_t *)meta->start + 1);
+    dev_meta.data_end = (void *)((uint8_t *)meta->start + meta->size);
+
+    printk("Registered console device successfully");
     return 0;
 }
 
-void test_module_exit(void) {
+void __attribute__((section(".module_exit"))) module_exit(void) {
+    printk("Unregistered console device (nothing to do)");
 }
diff --git a/include/log.h b/include/log.h
index 2b35922..f1e4110 100644
--- a/include/log.h
+++ b/include/log.h
@@ -2,5 +2,7 @@
 
 #define RINGBUF_SIZE 64 * 1024
 
+typedef void (*console_callback_t)(char);
+
 void vprintk(const char *message, __builtin_va_list args);
 void printk(const char *message, ...);
diff --git a/include/mmio.h b/include/mmio.h
new file mode 100644
index 0000000..b6531bf
--- /dev/null
+++ b/include/mmio.h
@@ -0,0 +1,8 @@
+#pragma once
+#include <types.h>
+
+struct mmio_device_meta {
+    const char *name;
+    void *start;
+    size_t size;
+};
diff --git a/kernel/log.c b/kernel/log.c
index 3392223..98267e3 100644
--- a/kernel/log.c
+++ b/kernel/log.c
@@ -4,10 +4,19 @@ __attribute__((section(".ringbuf"), aligned(64)))
 volatile char log_ring[RINGBUF_SIZE];
 static int pos = 0;
 
+void stub(char c) {
+    (void)c;
+    return;
+}
+
+console_callback_t callback = stub;
+
 void put_char(char c) {
     log_ring[pos++] = c;
     if (pos >= RINGBUF_SIZE)
         pos = 0;
+
+    callback(c);
 }
 
 void put_string(const char *s) {
-- 
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