1 files changed, 43 insertions, 0 deletions
diff --git a/kernel/entry.asm b/kernel/entry.asm
new file mode 100644
index 0000000..28e491a
--- /dev/null
+++ b/kernel/entry.asm
@@ -0,0 +1,43 @@
+global _start
+global stack_ptr
+
+extern kernel_main
+
+; declare some constants
+MODULEALIGN equ 1<<0            ; align loaded modules on page boundaries
+MEMINFO equ 1<<1                ; provide memory map
+FLAGS equ MODULEALIGN | MEMINFO ; this is the Multiboot 'flag' field
+MAGIC equ 0x1BADB002            ; 'magic number' lets bootloader find the header
+CHECKSUM equ -(MAGIC + FLAGS)   ; checksum of above, to prove we are multiboot
+
+; the bootloader will search for this magic sequence
+; and recognize us as a multiboot kernel
+section .multiboot
+align 4
+MultiBootHeader:
+  dd MAGIC
+  dd FLAGS
+  dd CHECKSUM
+
+section .code
+; setup the stack
+STACKSIZE equ 0x16384
+
+_start:
+  mov esp, stack+STACKSIZE
+  push eax
+  push ebx
+
+  call kernel_main
+
+  cli
+
+hang:
+  hlt
+  jmp hang
+
+section .bss
+align 4
+stack:
+  resb STACKSIZE
+stack_ptr: