ADV: EDD "write with verify" is AL=01h or AL=02h, not AL=80h
authorH. Peter Anvin <hpa@zytor.com>
Thu, 30 Apr 2009 22:55:29 +0000 (15:55 -0700)
committerH. Peter Anvin <hpa@zytor.com>
Thu, 30 Apr 2009 22:55:29 +0000 (15:55 -0700)
The "write with verify" functionality in EDD is AL=01h or AL=02h
depending on EDD version, not AL=80h.  Since it is apparently
version-dependent, don't even try to do it; furthermore, some BIOSes
are known to reject a write with this feature requested no matter
what.  At some point we may want to explicitly read back to verify.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
core/adv.inc

index 03bb25d..d856a1a 100644 (file)
@@ -384,7 +384,7 @@ adv_read_write:
                mov si,sp
                pushad
                mov dl,[ADVDrive]
-               mov ax,4080h
+               mov ax,4000h
                or ah,[ADVOp]
                push ds
                push ss