M boot/boot.s → boot/boot.s

@@ -24,18 +24,20 @@ movb $0, %al
   movb $0x05, %ah
   int $0x10
 
-  # print hello world
-  movw $message, %si
-  call print
-
   # TODO:
   # - activate A20 gate
 
   # reset bootdrive
 reset:
+  movw $reset_msg, %si
+  call print
+
   movb $0x00, %ah
   int $0x13
-  jc reset
+  jc error
+
+  movw $done_msg, %si
+  call print
 
   # load second stage into memory starting at adress 0x10000
   #   (NOTE: this code can only be jumped to after loading the global descriptor table
@@ -43,20 +45,33 @@ #          because it uses absolute adresses larger than 16 bit)
   #   (NOTE2: this routine only loads 0x48 sectors of the second stage into memory
   #          and is in general pretty whacky. should be replaced with sth more serious)
 load:
+  movw $load_msg, %si
+  call print
+
   movw $0x0000, %bx   # buffer address
   movw $0x1000, %ax
   movw %ax, %es       # buffer address (segment)
   movb $0x02, %ah     # function 0x02: read a sector
-  movb $0x48, %al     # sectors to read count
+  movb $0x048, %al     # sectors to read count
   movb $0x00, %ch     # cylinder
   movb $0x02, %cl     # sector
   movb $0x00, %dh     # head
   # dl (drive) keep as is
   int $0x13
-  jnc load
+  jc error
+
+  movw $done_msg, %si
+  call print
+
+  movw $gdt_msg, %si
+  call print
 
   # - load global descriptor table and far jump into protected mode
   lgdt (GDT_DESCRIPTOR)
+
+  movw $done_msg, %si
+  call print
+
   lidt (IDT_DESCRIPTOR)
 
   mov %cr0, %eax
@@ -79,6 +94,11 @@ # jump to second stage code
   ljmp $0x08, $_ss_start
 
 .code16
+error:
+  movw $fail_msg, %si
+  call print
+error_loop:
+  jmp error_loop
 
   # ############################################
   # print
@@ -98,10 +118,26 @@ jmp print_loop
 print_end:
   ret
 
+reset_msg: 
+  .ascii "Resetting bootdrive..."
+  .byte 0
 
-  # some data
-message: 
-  .ascii "Hello World!"
+load_msg: 
+  .ascii "Loading bootdrive..."
+  .byte 0
+
+gdt_msg:
+  .ascii "Setting GDT..."
+  .byte 0
+
+done_msg:
+  .ascii "done"
+  .byte 13
+  .byte 10
+  .byte 0
+
+fail_msg:
+  .ascii "fail"
   .byte 13
   .byte 10
   .byte 0

M makefile → makefile

@@ -6,7 +6,7 @@ export INCLUDE_DIR		= $(CURRENT_DIR)/include
 export DEBUG_DIR		= $(CURRENT_DIR)/debug
 
 export GCC_PREFIX		= $(HOME)/opt/cross/i686-elf-/bin/i686-elf-
-export GCC_OPTIONS		= -O0 -Wno-write-strings -Wall -Wextra -fno-exceptions -nostdlib -nostartfiles -ffreestanding
+export GCC_OPTIONS		= -O0 -Wno-write-strings -Qn -Wall -Wextra -fno-exceptions -nostdlib -nostartfiles -ffreestanding
 
 # OBJ_FILES = $(wildcard obj/asm/*.o) $(wildcard obj/cpp/*.o)
 

M run.sh → run.sh

@@ -1,1 +1,1 @@
-qemu -L .\ -fda build/base.img -m 64 -monitor stdio -no-reboot -d int,cpu_reset 2> debug/err.log+qemu -drive index=0,if=floppy,format=raw,file=build/base.img -m 64 -monitor stdio -no-reboot -d int,cpu_reset 2> debug/err.log