Add serial0 console output

2 files changed, 35 insertions, 14 deletions

diff --git a/libk/stdlib.h b/libk/stdlib.h
index a336586..7213384 100644
--- a/libk/stdlib.h
+++ b/libk/stdlib.h
@@ -2,15 +2,32 @@
 
 #include <string.h>
 
+template <typename T, bool reverse = false>
+class Iterator {
+public:
+  T next() { return buffer[reverse ? pos-- : pos++]; }
+  operator bool() const { return reverse ? (pos >= 0) : (pos < length); }
+
+  explicit Iterator(T* b, size_t l) : buffer(b), length(l) {
+    if (reverse)
+      pos = length - 1;
+  };
+
+private:
+  ssize_t pos = 0;
+  T* const buffer;
+  const size_t length;
+};
+
 class Console {
- public:
-   virtual ~Console() = default;
-   virtual void write(char c) = 0;
-   virtual void write(ViewIterator& msg) = 0;
-   virtual void update_cursor() = 0;
-
-   static void set(Console* ptr);
-   static Console* get();
+public:
+  virtual ~Console() = default;
+  virtual void write(char c) = 0;
+  virtual void write(ViewIterator& msg) = 0;
+  virtual void update_cursor() = 0;
+
+  static void set(Console* ptr);
+  static Iterator<Console*> begin();
 };
 
 template <typename T>
@@ -37,7 +54,9 @@ void print_c(Console* console, const T& a, const Args&... x) {
 
 template <typename T, typename... Args>
 void printk(const T& a, const Args&... x) {
-  if (auto* c = Console::get()) {
+  auto iter = Console::begin();
+  while (iter) {
+    auto* c = iter.next();
     print_c(c, a, x...);
     c->update_cursor();
   }
diff --git a/libk/stdlib/console.cc b/libk/stdlib/console.cc
index 308f055..a234e6b 100644
--- a/libk/stdlib/console.cc
+++ b/libk/stdlib/console.cc
@@ -1,15 +1,17 @@
 #include "stdlib.h"
 
-static Console* global_console = nullptr;
+constexpr size_t max_consoles = 4;
+static Console* global_console[max_consoles] = {nullptr};
+static size_t last_console = 0;
 
 void Console::set(Console* ptr) {
-  if (ptr != nullptr) {
-    global_console = ptr;
+  if (ptr != nullptr && last_console < max_consoles) {
+    global_console[last_console++] = ptr;
   }
 }
 
-Console* Console::get() {
-  return global_console;
+Iterator<Console*> Console::begin() {
+  return Iterator<Console*>(global_console, last_console);
 }
 
 void abort() {