1 files changed, 46 insertions, 0 deletions
diff --git a/mini-os/head.S b/mini-os/head.S
new file mode 100644
index 0000000000..3f4e6670c3
--- /dev/null
+++ b/mini-os/head.S
@@ -0,0 +1,46 @@
+#include <os.h>
+
+/* Offsets in start_info structure */
+#define SHARED_INFO  4
+#define MOD_START   12
+#define MOD_LEN     16
+
+#define ENTRY(X) .globl X ; X :
+
+.globl _start                
+_start:
+        cld
+        
+        lss stack_start,%esp
+        
+        /* Copy any module somewhere safe before it's clobbered by BSS. */
+        mov  MOD_LEN(%esi),%ecx
+        shr  $2,%ecx
+        jz   2f        /* bail from copy loop if no module */
+        
+        mov  $_end,%edi
+        add  MOD_LEN(%esi),%edi
+        mov  MOD_START(%esi),%eax
+        add  MOD_LEN(%esi),%eax
+1:      sub  $4,%eax
+        sub  $4,%edi
+        mov  (%eax),%ebx
+        mov  %ebx,(%edi)
+        loop 1b
+        mov  %edi,MOD_START(%esi)
+
+        /* Clear BSS first so that there are no surprises... */
+2:      xorl %eax,%eax
+	    movl $__bss_start,%edi
+	    movl $_end,%ecx
+	    subl %edi,%ecx
+	    rep stosb
+
+        push %esi 
+        call start_kernel
+
+
+stack_start:
+	.long stack+8192, __KERNEL_DS
+
+