Bug 20694 - PDP11 TARGET_PAGE_SIZE is incorrect
Summary: PDP11 TARGET_PAGE_SIZE is incorrect
Status: UNCONFIRMED
Alias: None
Product: binutils
Classification: Unclassified
Component: ld (show other bugs)
Version: 2.27
: P2 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-10-17 07:06 UTC by Stephen Casner
Modified: 2018-12-12 16:37 UTC (History)
1 user (show)

See Also:
Host:
Target:
Build:
Last reconfirmed:


Attachments

Note You need to log in before you can comment on or make changes to this bug.
Description Stephen Casner 2016-10-17 07:06:40 UTC
The file ld/emulparams/pdp11.sh includes the line:

TARGET_PAGE_SIZE=256

The actual page size of the memory management hardware on the PDP11/45, PDP11/70, etc. is 8192 bytes.  A consequence of this error is that the data section in a.out format output is not offset to a page boundary.

I have verified that the UNIX V6 ld program running on a simulated PDP11 does offset the data section to the next page boundary (20000 octal) when the -n option is included.
Comment 1 James Patrick Conlon 2018-08-21 17:06:49 UTC
8192 is the correct page size for the PDP-11.  There are two spots where it will need to be changed.  The linker and the bfd both are at 256.

Once I can test an actual executable on 2.11BSD and UNIX v7, I'll submit a patch.
Comment 2 Stephen Casner 2018-09-01 17:46:35 UTC
Thanks for picking up this bug.
Comment 3 Stephen Casner 2018-12-12 16:37:58 UTC
Do you need assistance with bringing up 2.11BSD and UNIX v7 systems on an emulated PDP11?  Those systems are included as examples prepared to run on the PiDP11/70 recreated model front panel that Oscar Vermeulen has produced that uses simh as the emulation and Blinkenbone as the communication API.  I could assist with running whatever tests you would like to see.