refactoring

1 files changed, 82 insertions, 0 deletions

diff --git a/kernel/src/arch/i686/start.asm b/kernel/src/arch/i686/start.asm
new file mode 100644
index 0000000..2151b51
--- /dev/null
+++ b/kernel/src/arch/i686/start.asm
@@ -0,0 +1,82 @@
+global start
+bits 32
+
+
+; create the multiboot header
+section .bootstrap.data
+align 8
+mb_start:
+dd 0xe85250d6
+dd 0
+dd mb_end - mb_start
+dd -(0xe85250d6 + (mb_end - mb_start))
+dw 0
+dw 0
+dd 8
+mb_end:
+
+
+; create the stack for bootstrapping
+section .bootstrap.stack
+align 16
+bootstrap_stack_start:
+resb 1024 ; 1 KiB
+bootstrap_stack_end:
+
+
+; create the stack for the kernel
+section .stack
+align 16
+stack_start:
+resb 16384 ; 16 KiB
+stack_end:
+
+
+; load the kernel into the higher half
+section .bootstrap.text
+align 8
+start:
+    ; init bootstrap stack
+	mov esp, bootstrap_stack_end
+	mov ebp, bootstrap_stack_end
+
+    ; load kernel into higher half and init paging
+    extern paging_init
+    call paging_init
+
+    jmp near load_kernel
+
+; initalize kernel after it has been loaded in higher half
+section .text
+align 8
+load_kernel:
+    ; init stack
+	mov esp, stack_end
+	mov ebp, stack_end
+    
+    ; load global descripter table
+    extern load_gdt
+    call load_gdt
+
+    ; unmap kernel at page 0
+    extern paging_finish
+    call paging_finish
+
+    ; initalize the FPU
+    finit                                  
+    
+    ; push multiboot header
+    extern KERNEL_MAPPING
+    add ebx, KERNEL_MAPPING
+    push ebx
+
+    ; start kernel
+	sti
+    call kernel_main
+    extern kernel_main
+	
+    ; hlt forever if kernel quits (it should never)
+    cli
+halt:
+	hlt
+	jmp halt