22 Apr
2013
22 Apr
'13
6:40 p.m.
I've got a little "satellite" PDP-11/23 with just a CPU, memory , some
serial ports and a BDV11 bootstrap card. One of the serial ports is
connected to a bigger PDP-11 running RSX-11M+ and DECnet-11M. My goal is to
use the DECnet MOP bootstrap built into the BDV11 to download a "bare metal"
application from the RSX system on the bigger -11.
So far, so good. After a little twiddling with the DECnet configuration
I've got it so that I can trigger the BDV11 boot and the host will download
the secondary and tertiary loaders to the satellite. Amazing :-) Now the
problem is for me to write some application for the tertiary loader to
download. Writing a PDP-11 assembly program is not an issue for me, and
I've got MACRO-11 and TKB on the host system, but I don't know exactly what
DECnet wants.
How is the application system image supposed to be made? What's the file
format that DECnet wants to download? It's probably made with TKB in some
way, but what are the proper TKB options? Where (in memory) does it get
loaded on the satellite? What address does it start execution at ? Is the
MMU turned on? Is the I/O page mapped? Are any useful values (e.g. a
pointer to a valid stack, the address of the download device CSR, etc)
passed in the registers? So many questions !
Can anybody point me to documentation on this, or an example of a little
program that gets downloaded via DECnet MOP?
In the olden days, people probably would have generated an RSX-11S system
and downloaded that, but I don't have an 11S kit so that's not an option.
Thanks,
Bob Armstrong
22 Apr
22 Apr
6:53 p.m.
On 22 Apr 2013, at 18:40, "Bob Armstrong" <bob at jfcl.com> wrote:
I've got a little "satellite" PDP-11/23 with just a CPU, memory , some
serial ports and a BDV11 bootstrap card. One of the serial ports is
connected to a bigger PDP-11 running RSX-11M+ and DECnet-11M. My goal is to
use the DECnet MOP bootstrap built into the BDV11 to download a "bare metal"
application from the RSX system on the bigger -11.
So far, so good. After a little twiddling with the DECnet configuration
I've got it so that I can trigger the BDV11 boot and the host will download
the secondary and tertiary loaders to the satellite. Amazing :-) Now the
problem is for me to write some application for the tertiary loader to
download. Writing a PDP-11 assembly program is not an issue for me, and
I've got MACRO-11 and TKB on the host system, but I don't know exactly what
DECnet wants.
How is the application system image supposed to be made? What's the file
format that DECnet wants to download? It's probably made with TKB in some
way, but what are the proper TKB options? Where (in memory) does it get
loaded on the satellite? What address does it start execution at ? Is the
MMU turned on? Is the I/O page mapped? Are any useful values (e.g. a
pointer to a valid stack, the address of the download device CSR, etc)
passed in the registers? So many questions !
Can anybody point me to documentation on this, or an example of a little
program that gets downloaded via DECnet MOP?
In the olden days, people probably would have generated an RSX-11S system
and downloaded that, but I don't have an 11S kit so that's not an option.
Does the trailing-edge ftp site have any RSX-11S kits?
Thanks,
Bob Armstrong
23 Apr
23 Apr
11:55 a.m.
Cory Smelosky [mailto:b4 at gewt.net] wrote:
Does the trailing-edge ftp site have any RSX-11S kits?
Thanks for the suggestion, but I've been there and Tim doesn't have any.
M and M+ distros, yes, but no 11S kits. I've done a pretty extensive Google
search and haven't found any RSX-11S kits online - it looks like nobody has
preserved them.
I did find a RSX-11S System Generation Guide (for v4.1), so if I ever do
find a kit I'll know what to do with it :-)
Thanks,
Bob
22 Apr
22 Apr
7:08 p.m.
On Mon, Apr 22, 2013 at 03:40:49PM -0700, Bob Armstrong wrote:
How is the application system image supposed to be
made? What's the file
format that DECnet wants to download? It's probably made with TKB in some
way, but what are the proper TKB options? Where (in memory) does it get
loaded on the satellite? What address does it start execution at ? Is the
MMU turned on? Is the I/O page mapped? Are any useful values (e.g. a
pointer to a valid stack, the address of the download device CSR, etc)
passed in the registers? So many questions !
Any chance it's similar to MOP over Ethernet? If so then I think you want
a fairly standard .TSK file with important stuff in block 0:
+10 (L$BSA) = .word <load address>
+16 (L$BLDZ) = .word <load size in 32-word MMU units>
+350 (L$BXFR) = .word <transfer address>
+360 (L$BBLK) = .word <total # 512-byte blks in header, e.g. 1>
Further guessing: MMU is off, so I/O page is available for groping.
Probably best to load the SP yourself. No idea if anything's guaranteed
about the other reg values but of course it's easy to find out what *happens*
to be in them. Boot ROMs have a tradition of passing the CSR in R1 and it'd
be nice if the pri/sec/etc. loaders did something similar but who knows.
John Wilson
D Bit
23 Apr
23 Apr
11:58 a.m.
John Wilson [mailto:wilson at dbit.com] wrote:
Any chance it's similar to MOP over Ethernet?
No idea, but it's a reasonable guess.
If so then I think you want a fairly standard .TSK
file with important
stuff in block 0:
+10 (L$BSA) = .word <load address>
+16 (L$BLDZ) = .word <load size in 32-word MMU units>
+350 (L$BXFR) = .word <transfer address>
+360 (L$BBLK) = .word <total # 512-byte blks in header, e.g. 1>
Is this all stuff that's in the task header? The RSX system image .SYS
file (the one on disk, for booting with the hardware boot) is built without
a task header (the TKB /-HD option) and things like the loading and starting
addresses are assumed somehow. I was guessing that the .SYS files for MOP
download would be the same, but maybe I'm wrong.
Bob
1:34 p.m.
On Tue, Apr 23, 2013 at 08:58:43AM -0700, Bob Armstrong wrote:
Is this all stuff that's in the task header?
Looks that way.
The RSX system image .SYS
file (the one on disk, for booting with the hardware boot) is built without
a task header (the TKB /-HD option) and things like the loading and starting
addresses are assumed somehow. I was guessing that the .SYS files for MOP
download would be the same, but maybe I'm wrong.
Here's where I'm getting hazy. I wrote a MOP boot server a few years ago
for debugging PDP-11 network booting (last I checked, the "mopd" package
doesn't support booting PDP-11s) and my notes show that I was pulling those
four fields out of the .TSK header, which should mean that I figured out that
that's how DEC does it. But I can't think what my test case must have been
(the .SYS files I have are for DSRVA and DSRVB), unless it all came from
fiddling with DECnet/RSX's own MOP server.
Well it would be very easy to prove me wrong -- making a .TSK file with a
stand-alone "Hello world" program would only take a couple of minutes.
Or I can send you a FORTH .SYS image I was using for testing on DELQA and
DELUA, but it'll take longer to download so testing will get annoying
quickly unless it magically works on the first try.
John Wilson
D Bit
3:44 p.m.
New subject: mopd - Re: DECnet MOP download file formats??
On 23/04/13 1:34 PM, John Wilson wrote:
On Tue, Apr 23, 2013 at 08:58:43AM -0700, Bob
Armstrong wrote:
Is there a more recent upstream than this fork I had to make? The fixes
that this required were probably already done by somebody but this was
the most recent code I could get hold of at the time...
https://github.com/qu1j0t3/mopd
--Toby
Is this all stuff that's in the task header?
Looks that way.
The RSX system image .SYS
file (the one on disk, for booting with the hardware boot) is built without
a task header (the TKB /-HD option) and things like the loading and starting
addresses are assumed somehow. I was guessing that the .SYS files for MOP
download would be the same, but maybe I'm wrong.
Here's where I'm getting hazy. I wrote a MOP boot server a few years ago
for debugging PDP-11 network booting (last I checked, the "mopd" package
doesn't support booting PDP-11s) and my notes show that I was pulling those
four fields out of the .TSK header, which should mean that I figured out that
that's how DEC does it. But I can't think what my test case must have been
(the .SYS files I have are for DSRVA and DSRVB), unless it all came from
fiddling with DECnet/RSX's own MOP server.
Well it would be very easy to prove me wrong -- making a .TSK file with a
stand-alone "Hello world" program would only take a couple of minutes.
Or I can send you a FORTH .SYS image I was using for testing on DELQA and
DELUA, but it'll take longer to download so testing will get annoying
quickly unless it magically works on the first try.
John Wilson
D Bit
4108
days inactive
4109
days old
6 comments
4 participants
participants (4)
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b4＠gewt.net -
bob＠jfcl.com -
toby＠telegraphics.com.au -
wilson＠dbit.com