[ros-diffs] [fireball] 27257: - Set GDT and IDT to the values ReactOS kernel expects. This gets us lots farther in the kernel, up to the BSOD with CONFIG_INITIALIZATION_FAILED.

Author: fireball
Date: Fri Jun 22 01:18:19 2007
New Revision: 27257

URL: http://svn.reactos.org/svn/reactos?rev=27257&view=rev
Log:
- Set GDT and IDT to the values ReactOS kernel expects. This gets us lots farther in the kernel, up to the BSOD with CONFIG_INITIALIZATION_FAILED.

Modified:
    branches/olpc/boot/freeldr/freeldr/arch/i386/arch.S
    branches/olpc/boot/freeldr/freeldr/arch/i386/loader.c

Modified: branches/olpc/boot/freeldr/freeldr/arch/i386/arch.S
URL: http://svn.reactos.org/svn/reactos/branches/olpc/boot/freeldr/freeldr/arch/i...
==============================================================================
--- branches/olpc/boot/freeldr/freeldr/arch/i386/arch.S (original)
+++ branches/olpc/boot/freeldr/freeldr/arch/i386/arch.S Fri Jun 22 01:18:19 2007
@@ -480,7 +480,7 @@
    .word	0x0000

/* GDT table pointer */
-gdtptr:
+EXTERN(gdtptr)
    .word	0x27		/* Limit */
    .long	gdt			/* Base Address */

Modified: branches/olpc/boot/freeldr/freeldr/arch/i386/loader.c
URL: http://svn.reactos.org/svn/reactos/branches/olpc/boot/freeldr/freeldr/arch/i...
==============================================================================
--- branches/olpc/boot/freeldr/freeldr/arch/i386/loader.c (original)
+++ branches/olpc/boot/freeldr/freeldr/arch/i386/loader.c Fri Jun 22 01:18:19 2007
@@ -19,6 +19,8 @@
  */
 #define _NTSYSTEM_
 #include <freeldr.h>
+
+#include <arch.h>

#define NDEBUG
 #include <debug.h>
@@ -56,6 +58,10 @@
                      PUCHAR SymbolName,
                      USHORT Hint);

+VOID FASTCALL
+FrLdrResetGdtIdt();
+
+
 /* FUNCTIONS *****************************************************************/

/*++
@@ -87,12 +93,54 @@
     /* Re-initalize EFLAGS */
     Ke386EraseFlags();

+    /* Point GDT+IDT to FreeLdr instead of OFW */
+    FrLdrResetGdtIdt();
+
     /* Initialize the page directory */
     FrLdrSetupPageDirectory();

/* Initialize Paging, Write-Protection and Load NTOSKRNL */
     FrLdrSetupPae(Magic);
 }
+
+/*++
+ * FrLdrResetGdtIdt
+ * INTERNAL
+ *
+ *     Sets GDT and IDT as to what ReactOS expects
+ *
+ * Params:
+ *     Magic - Multiboot Magic
+ *
+ * Returns:
+ *     None.
+ *
+ * Remarks:
+ *     None.
+ *
+ *--*/
+VOID
+FASTCALL
+FrLdrResetGdtIdt()
+{
+    /* Load the GDT and IDT */
+    asm("lgdt	gdtptr\n\
+        lidt	i386idtptr\n");
+
+    /* Clear prefetch queue & correct CS,
+    * jump to low mem */
+    asm("ljmp	$0x08, $mb4\n\
+         mb4:\n");
+
+    /* Reload segment selectors */
+    asm("movw	$0x10,%dx\n\
+        movw	%dx,%ds\n\
+        movw	%dx,%es\n\
+        movw	%dx,%fs\n\
+        movw	%dx,%gs\n\
+        movw	%dx,%ss\n");
+}
+

/*++
  * FrLdrSetupPae