Changeset 2651 in vbox for trunk/src/VBox/Devices/PC/BIOS

Timestamp:

May 15, 2007 8:21:06 PM (18 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

21185

Message:

provide MPS table if IOAPIC is present, use the last 16 bytes of the EBDA for MPS floating pointer structure

File:

• trunk/src/VBox/Devices/PC/BIOS/rombios.c (modified) (3 diffs)

trunk/src/VBox/Devices/PC/BIOS/rombios.c

@@ -768 +768 @@
 
     } ebda_data_t;
+
+#ifdef VBOX
+  // the last 16 bytes of the EBDA segment are used for the MPS floating
+  // pointer structure (only if an IOAPIC is present)
+#endif
 
   #define EbdaData ((ebda_data_t *) 0)
@@ -10383 +10388 @@
   rep
     stosw
-  ;; zero out remaining base memory
+  ;; zero out remaining base memory except the last 16 bytes of the EBDA
+  ;; because we store the MP table there
   xor eax, eax
   xor bx, bx
 memory_zero_loop:
   add bx, #0x1000
-  cmp bx, #0xa000
+  cmp bx, #0x9000
   jae memory_cleared
   mov es, bx
@@ -10397 +10403 @@
   jmp memory_zero_loop
 memory_cleared:
+  mov es, bx
+  xor di, di
+  mov cx, #0x3f00
+  rep
+    stosd
   xor bx, bx
 #endif