[Info-vax] I64 generic drive boot pointer w/o embedded GUID?

[Stephen Hoffman]

On 2019-11-28 17:42:37 +0000, Rod Regier said:

> Is it possible to create a setup on an Integrity server with an OpenVMS 
> boot pointer that would work generically without requiring a specific 
> GUID volume being present for the boot input?

Typically, no.  EFI very specifically went against what you want to do 
here, as that's not how Microsoft Windows wanted to tie itself to a 
platform and into an install.

You'll likely want to concentrate on the EFI commands to add and remove 
the boot aliases necessary, either using BOOT_OPTIONS or the underlying 
command, or using the EFI-level equivalent, or an analog.

That written, OpenVMS does have a way to avoid changing the boot GUIDs, 
and that might be useful to you here.  That's supposed to happen with 
each install, but the signature-preservation qualifier/switch overrides 
it.

Some of what little is available on sys$setboot / SET BOOTBLOCK:  
http://h30266.www3.hpe.com/odl/axpos/opsys/vmsos84/Z7550_96158/babdfjig.html 


In addition to serving SET BOOTBLOCK command, the sys$setboot.exe image 
can be available as a foreign command among other invocation paths, and 
there was some help text available within there.  That tool can also 
decode bootblocks, and can create DCL symbols containing relevant 
contents.  Also see the EFI$HELP.HLB help library for some related 
details.

Also see the EFI specs for details here.  Beyond the GUIDs you're aware 
of, EFI also embeds the size and offset of the boot partition, which 
makes this whole effort a little more involved.

Theoretically, if you had the same GUIDs and the same boot partition 
offset and size, what you want might well work—disk imaging, not a 
BACKUP /IMAGE—but it'll be involved. And you'll still need to add the 
initial entry.

I'd probably use a customized optical-media installer, as that does 
insinuate itself into the first position in the boot path, and that 
could (theoretically) be coded to allow what you want to have happen 
here, though for whatever OpenVMS installation happens to be present.


-- 
Pure Personal Opinion | HoffmanLabs LLC