The refreshable code in OS/360 ran in key 0. There wa no APF, and Fetch didn't look at the RENT attribute. Fetch loaded code from the link list into SP 252, which was key 0, but some of that code was self modifying.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of Paul Gilmartin [0000000433f07816-dmarc-requ...@listserv.ua.edu] Sent: Monday, February 8, 2021 5:46 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: LINK vs LOAD/CALL On Mon, 8 Feb 2021 22:35:13 +0000, Seymour J Metz wrote: >IBM initially only used REFR in the Machine Check Handler (MCH), which could >recover from a parity error in, e.g., a transient SVC, by reading in a fresh >copy. There was no non-modifiable storage at the time. > Couldn't storage keys prevent modification? >REFR stopped being relevant in SVS, and only became relevant with the support >of REFRPROT. > Weren't REFR modules in APF-authorized libraries loaded into a protected subpool? >What happens if you have an RSECT but don't bind with REFR? > Binder or assembler should mark RSECTs REFR. That may require scatter-loading. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
