Changes in kernel/arch/amd64/src/asm.S [b5382d4f:22c3444] in mainline

File:

• kernel/arch/amd64/src/asm.S (modified) (5 diffs)

kernel/arch/amd64/src/asm.S

@@ -347 +347 @@
  * Since the EGA can only display Extended ASCII (usually
  * ISO Latin 1) characters, some of the Unicode characters
- * can be displayed in a wrong way. Only the newline character
- * is interpreted, all other characters (even unprintable) are
+ * can be displayed in a wrong way. Only newline and backspace
+ * are interpreted, all other characters (even unprintable) are
  * printed verbatim.
  *
@@ -399 +399 @@
         
         cmp $0x0a, %al
-        jne early_putchar_print
+        jne early_putchar_backspace
         
                 /* Interpret newline */
@@ -413 +413 @@
                 subw %dx, %bx
                 
-                jmp early_putchar_newline
+                jmp early_putchar_skip
+        
+        early_putchar_backspace:
+        
+                cmp $0x08, %al
+                jne early_putchar_print
+                
+                /* Interpret backspace */
+                
+                cmp $0x0000, %bx
+                je early_putchar_skip
+                
+                dec %bx
+                jmp early_putchar_skip
         
         early_putchar_print:
@@ -423 +436 @@
                 inc %bx
         
-        early_putchar_newline:
+        early_putchar_skip:
         
         /* Sanity check for the cursor on the last line */
@@ -432 +445 @@
                 movq $(PA2KA(0xb80a0)), %rsi
                 movq $(PA2KA(0xb8000)), %rdi
-                movq $1920, %rcx
-                rep movsw
+                movq $480, %rcx
+                rep movsq
                 
                 /* Clear the 24th row */
                 xorq %rax, %rax
-                movq $80, %rcx
-                rep stosw
+                movq $20, %rcx
+                rep stosq
                 
                 /* Go to row 24 */