diff --git a/bootloader-legacy/boot.asm b/bootloader-legacy/boot.asm
index 3610c40fbe2e0d45c3ae203c9aac826678c6f0e9..58d580180a55f705942740cb05a38a8212d39eab 100644
--- a/bootloader-legacy/boot.asm
+++ b/bootloader-legacy/boot.asm
@@ -70,7 +70,7 @@ _load_kern:
 disk_io_error:
     mov bx, _motd_disk_error
     call println_bios
-    jmp _stall
+    jmp $
 
 
 
@@ -121,7 +121,7 @@ _call_kern_32:
     ; Kernel returns.
     mov ebx, _motd_endk
     call println_vga
-    jmp _stall
+    jmp $
 
 [bits 64]
 _call_kern_64:
@@ -129,15 +129,12 @@ _call_kern_64:
     call KERN_ADDR
 
     ; Kernel returns.
-    mov ebx, _motd_endk
-    call println_vga
-    jmp _stall
-
-
-[bits 32]
-_stall:
+    ;mov ebx, _motd_endk
+    ;call println_vga
+    ; TODO: add 64bit println_vga and error msg
     jmp $
 
+
 _motd_disk_error:
     db 'MED', 0x0
 _motd_32:
diff --git a/kernel/Makefile b/kernel/Makefile
index a1f522b3820ca7631cf5b0342df132d98190fa35..91ca42462d6043efe5769cfce8ee8fc81fa35755 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -16,11 +16,11 @@ assemble: kernel head
 	truncate --size=65024 kernel.img
 
 head:
-	nasm -f elf -DBITS=$(BITS) image_head.asm -o image_head.o
+	nasm -f elf$(BITS) -DTARGET_BITS=$(BITS) image_head.asm -o image_head.o
 
 kernel:
 	g++ -ffreestanding -fno-pie -c kernel.cc -o kernel.o -m$(BITS) -std=c++17
 
 clean:
-	rm *.o *.img
+	rm -f *.o *.img
 
diff --git a/kernel/image_head.asm b/kernel/image_head.asm
index f6d9c3b5503f04e8d4de215858a80b32a78bc853..92c3af292ee64f06f6742a71ca49be3bb878cb91 100644
--- a/kernel/image_head.asm
+++ b/kernel/image_head.asm
@@ -1,4 +1,4 @@
-[bits 32]
+[bits TARGET_BITS]
 [extern main]
 call main
 ret
diff --git a/kernel/image_head_64.asm b/kernel/image_head_64.asm
deleted file mode 100644
index b2f3d2ebbccd06848b21c5ac4abeeb3731d74e28..0000000000000000000000000000000000000000
--- a/kernel/image_head_64.asm
+++ /dev/null
@@ -1,4 +0,0 @@
-[bits 64]
-[extern main]
-call main
-ret
diff --git a/kernel/include/vga.hpp b/kernel/include/vga.hpp
index ffebbc37c2d50dad6e8cc22c4894a77c8c8efdc8..6eab67984e5dd914bd828cdf3f2a952de6b696f5 100644
--- a/kernel/include/vga.hpp
+++ b/kernel/include/vga.hpp
@@ -12,7 +12,6 @@ constexpr uint16_t VGA_MAKE_CHAR(char c, uint8_t color) {
 }
 constexpr uint8_t default_color = 0x0f;
 
-
 inline void trigger_scroll(uint16_t *pos) {
     for(uint16_t row = 1; row < VGA_HEIGHT; ++row) {
         memcpy(VGA_BEGIN_ADDR + (row-1)*VGA_WIDTH, VGA_BEGIN_ADDR + row*VGA_WIDTH, VGA_WIDTH);
diff --git a/kernel/kernel.cc b/kernel/kernel.cc
index 576ca5a33264f8ff16693df72a50f0b57adbea2a..c1639a83a8d31732d72d9f99cd40289542e817ab 100644
--- a/kernel/kernel.cc
+++ b/kernel/kernel.cc
@@ -14,7 +14,7 @@ void main() {
         for(auto x = 0; x < 80; ++x) {
             char c = x%10 + '0';
             char color = x + y*80;
-            set_char(x, y, ' ', 0x0f);
+            set_char(x, y, 'F', 0x0f);
         }
     }
     print("Hello world!\n");