Article 169169 of comp.os.vms:
[snip]
>One problem I have is that the code to get the image link date from
>the image header doesn't work after being VESTed.

>The code is like:
>
>        movl    cli$a_imghdadr(ap), r2  ; get address of image buffer
>        cvtwl   ihd$w_imgidoff(r2), r0
>        movab   (r2)[r0], r2            ; address of ID block
>[...]
>        pushaq  ihi$q_linktime(r2)              ; LINK date-time
>        pushab  ihi$t_imgid(r2)                 ; .ascic image identification
>
>Both the image ID and date must be nulls.
>The ihd$ and ihi$ offsets seem to be the same on VAX and Alpha.
>Any help appreciated.

The IH%$ offsets refer to VAX images. There are corresponding EIH%$ symbols for
Alpha images. If you're just referring to your own image on Alpha, you can
safely change the symbols over. If you need to handle both image types from
either architecture, I've looked at the first longword to determine what sort
of header I've got. This is EIHD$L_MAJORID on Alpha, or IHD$W_SIZE,
IHD$W_ACTIVOFF on VAX, so if the value is less than IHD$K_LENGTH it's Alpha.
If there's a 'better' (ie supported) way of telling them apart I'd like to know
about it too.

Eg:
	movl    cli$a_imghdadr(ap), r2  ; get address of image buffer
	cmpl	eihd$l_majorid(r2), #ihd$k_length
	blssu	1$			; Alpha image

        cvtwl   ihd$w_imgidoff(r2), r0
        movab   (r2)[r0], r2            ; address of ID block
[...]
        pushaq  ihi$q_linktime(r2)              ; LINK date-time
        pushab  ihi$t_imgid(r2)                 ; .ascic image identification
	brb	2$

1$:	addl	eihd$l_imgidoff(r2), r2
[...]
	pushaq	eihi$q_linktime(r2)
	pushab	eihi$t_imgid(r2)
2$:
______________________________________________________________________
Chris Sharman			chris@ccagroup.co.uk
Tel: +(44) 1772 662883		Fax: +(44) 1772 662893
CCA Stationery Ltd, Eastway, Fulwood, Preston, Lancs, PR2 9WS, ENGLAND