Another 3 bytes or so off the MBR...

diff --git a/mbr/mbr.S b/mbr/mbr.S
index 6130303..ecab4e9 100644 (file)
--- a/mbr/mbr.S
+++ b/mbr/mbr.S
@@ -176,6 +176,8 @@ scan_partition_table:
        movw    $ptab, %di
        movw    $4, %cx
        xorw    %ax, %ax
+       push    %di
+       push    %cx
 5:
        testb   $0x80, (%di)
        jz      6f
@@ -185,13 +187,13 @@ scan_partition_table:
        addw    $16, %di
        loopw   5b
 
-       cmpw    $1, %ax         /* Number of active partitions found */
-       je      boot
-       ja      too_many_active
+       decw    %ax             /* Number of active partitions found */
+       jz      boot
+       jns     too_many_active
 
        /* No active partitions found, look for extended partitions */
-       movw    $ptab, %di
-       movb    $4, %cl         /* cx == 0 here */
+       popw    %di             /* %di <- ptab */
+       popw    %cx             /* %cx <- 4    */
 7:
        movb    4(%di), %al
        cmpb    $0x0f, %al      /* 0x0f = Win9x extended */