Changeset 36731 in vbox for trunk/src/VBox/Devices/PC

Timestamp:

Apr 19, 2011 3:51:47 PM (14 years ago)

Author:

vboxsync

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

71257

Message:

BIOS: Corrected EDD checksum calculation - two's complement is not one's complement.

File:

• trunk/src/VBox/Devices/PC/BIOS/rombios.c (modified) (4 diffs)

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

@@ -5886 +5886 @@
         checksum=0;
         for (i=0; i<15; i++) checksum+=read_byte(ebda_seg, (&EbdaData->ata.dpte) + i);
-        checksum = ~checksum;
+        checksum = -checksum;
         write_byte(ebda_seg, &EbdaData->ata.dpte.checksum, checksum);
         }
@@ -5934 +5934 @@
         checksum=0;
         for (i=30; i<64; i++) checksum+=read_byte(DS, SI + i);
-        checksum = ~checksum;
+        checksum = -checksum;
         write_byte(DS, SI+(Bit16u)&Int13DPT->checksum, checksum);
         }
@@ -6234 +6234 @@
         checksum=0;
         for (i=0; i<15; i++) checksum+=read_byte(ebda_seg, (&EbdaData->ata.dpte) + i);
-        checksum = ~checksum;
+        checksum = -checksum;
         write_byte(ebda_seg, &EbdaData->ata.dpte.checksum, checksum);
         }
@@ -6282 +6282 @@
         checksum=0;
         for (i=30; i<64; i++) checksum+=read_byte(DS, SI + i);
-        checksum = ~checksum;
+        checksum = -checksum;
         write_byte(DS, SI+(Bit16u)&Int13DPT->checksum, checksum);
         }