[Teton] Print out every character into the framebuffer as a test.

sys/teton/framebuffer/console.cpp

@@ -1,15 +1,25 @@
 #include "framebuffer/console.h"
 
+#include <mammoth/debug.h>
+
 void Console::WriteChar(char c) {
+  if (c == '\n') {
+    CursorReturn();
+    return;
+  }
+
   uint64_t row = cursor_pos_ / cols();
+  if (row >= rows()) {
+    crash("Unimplemented console scroll.", glcr::UNIMPLEMENTED);
+  }
   uint64_t fb_row = row * (psf_.height() + 1);
   uint64_t col = cursor_pos_ % cols();
   uint64_t fb_col = col * (psf_.width() + 1);
 
   uint8_t* glyph = psf_.glyph(c);
 
-  for (uint8_t r = fb_row; r < fb_row + psf_.height(); r++) {
-    for (uint8_t c = fb_col; c < fb_col + psf_.width(); c++) {
+  for (uint32_t r = fb_row; r < fb_row + psf_.height(); r++) {
+    for (uint32_t c = fb_col; c < fb_col + psf_.width(); c++) {
       uint8_t glyph_offset = psf_.width() - (c - fb_col) - 1;
       if ((glyph[r] & (1 << glyph_offset))) {
         framebuf_.DrawPixel(r, c, 0xFFFFFFF);
@@ -21,8 +31,14 @@ void Console::WriteChar(char c) {
 
   cursor_pos_++;
 }
+
 void Console::WriteString(glcr::StringView str) {
   for (uint64_t i = 0; i < str.size(); i++) {
     WriteChar(str[i]);
   }
 }
+
+void Console::CursorReturn() {
+  cursor_pos_ -= cursor_pos_ % cols();
+  cursor_pos_ += cols();
+}

sys/teton/framebuffer/console.h

@@ -20,4 +20,7 @@ class Console {
   Framebuffer& framebuf_;
   Psf& psf_;
   uint64_t cursor_pos_ = 0;
+
+  void CursorIncr();
+  void CursorReturn();
 };

sys/teton/teton.cpp

@@ -41,7 +41,10 @@ uint64_t main(uint64_t init_port) {
   psf.DumpHeader();
 
   Console console(fbuf, psf);
-  console.WriteString("Hello World!");
+  console.WriteString("Hello World!\n");
+  for (uint8_t i = 0x20; i < 0x7E; i++) {
+    console.WriteChar(i);
+  }
 
   // 3. Write a line to the screen.