Cleaning code and provide minimal libc

1 files changed, 58 insertions, 0 deletions

diff --git a/src/utils/framebuffer.c b/src/utils/framebuffer.c
new file mode 100644
index 0000000..110dc73
--- /dev/null
+++ b/src/utils/framebuffer.c
@@ -0,0 +1,58 @@
+#include "framebuffer.h"
+
+#define MAX_COL 80
+#define MAX_LINE 25
+
+VIDEO_STATE VS={
+  (u8 *)0xB8000,
+  0,
+  0,
+  BLACK,
+  GRAY,
+};
+
+void putchar(char c){
+  // Handle newline here
+  if(c=='\n'){
+    VS.col=0;
+    VS.line+=1;
+    if(VS.line>=MAX_LINE){
+      VS.line=MAX_LINE-1;
+      scrollup();
+    }
+    return;
+  }
+  
+  // Print char
+  VS.mem[VS.col*2+MAX_COL*VS.line*2]=c;
+  VS.mem[VS.col*2+MAX_COL*VS.line*2+1]=VS.fg|VS.bg<<4;
+  
+  // Refresh location
+  VS.col+=1;
+  if(VS.col>= MAX_COL){
+    VS.col=0;
+    VS.line+=1;
+    if(VS.line>=MAX_LINE){
+      VS.line=MAX_LINE-1;
+      scrollup();
+    }
+  }
+}
+
+void clear(){
+  for(char i=0;i<MAX_LINE;i++){
+    scrollup();
+  }
+}
+
+void scrollup(){
+  // Move VS.line up
+  for(char i=1;i<=MAX_LINE;i++){
+    for(char j=0;j<=MAX_COL;j++)
+      VS.mem[j*2+MAX_COL*(i-1)*2]=VS.mem[j*2+MAX_COL*i*2];
+  }
+  // Clear last VS.line
+  for(char i=0;i<=MAX_COL;i++){
+    VS.mem[i*2+MAX_COL*(MAX_LINE-1)*2]='\0';
+  }
+}