gdt cleanup, reorder info collection to start

1 files changed, 13 insertions, 41 deletions

diff --git a/kernel/gdt.h b/kernel/gdt.h
index 314cc99..9b7eece 100644
--- a/kernel/gdt.h
+++ b/kernel/gdt.h
@@ -1,49 +1,21 @@
 // https://xarnze.com/posts/post/Tutorial:%20Entering%20User%20mode
 // http://wiki.osdev.org/TSS
 // http://wiki.osdev.org/Global_Descriptor_Table
+// http://wiki.osdev.org/GDT_Tutorial
+//https://wiki.osdev.org/Task_State_Segment
 
 #include <stdint.h>
 
-typedef volatile struct strtss{
-    unsigned short   link;
-    unsigned short   link_h;  
-    unsigned long   esp0;
-    unsigned short   ss0;
-    unsigned short   ss0_h;  
-    unsigned long   esp1;
-    unsigned short   ss1;
-    unsigned short   ss1_h;  
-    unsigned long   esp2;
-    unsigned short   ss2;
-    unsigned short   ss2_h;  
-    unsigned long   cr3;
-    unsigned long   eip;
-    unsigned long   eflags;  
-    unsigned long   eax;
-    unsigned long   ecx; 
-    unsigned long   edx;
-    unsigned long    ebx;  
-    unsigned long   esp;
-    unsigned long   ebp;  
-    unsigned long   esi;
-    unsigned long   edi;  
-    unsigned short   es;
-    unsigned short   es_h;  
-    unsigned short   cs;
-    unsigned short   cs_h;  
-    unsigned short   ss;
-    unsigned short   ss_h;  
-    unsigned short   ds;
-    unsigned short   ds_h;  
-    unsigned short   fs;
-    unsigned short   fs_h;  
-    unsigned short   gs;
-    unsigned short   gs_h;  
-    unsigned short   ldt;
-    unsigned short   ldt_h;  
-    unsigned short   trap;
-    unsigned short   iomap;  
-}__attribute__((packed)) tss_struct;  
-
+/** Call this one on each CPU to get a fresh 6-entries GDT 
+ * * 0
+ * * ring0 code
+ * * ring0 data
+ * * ring3 code
+ * * ring3 data
+ * * tss
+ */
 void gdt_init();
+
+/** update tss.esp0 for a given cpu
+ */
 void install_tss(uint32_t cpu,uint32_t esp0);