add comment about location that may be modified by sys (and some whitespace changes due to editor)

git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@1493 6ac86273-5f31-0410-b378-82cca8765d1b

boot/boot.asm

@@ -401,6 +401,8 @@ read_next:
                 mov     ah,041h                 ;
                 mov     bx,055aah               ;
                 mov     dl, [drive]
+
+                ; NOTE: sys must be updated if location changes!!!
                 test    dl,dl                   ; don't use LBA addressing on A:
                 jz      read_normal_BIOS        ; might be a (buggy)
                                                 ; CDROM-BOOT floppy emulation
@@ -536,3 +538,4 @@ PrintNumber:            ; Prints (in Hex) value in AX, AX is preserved
         call PrintAL
         retn
 %endif
+