On Wed, 5 Apr 2023 12:40:50 +0000, Seymour J Metz wrote: >I wonder why the Unix System Services documentation doesn't match the TSO/E >documentation. > Different things? The UNIX doc for BPXWDYN requires that R0 contain 0. The TSO/E doc for IRXEXCOM says R0 is optionally(???) the address of the ENVBLOCK, maybe something else.
>________________________________________ >From: I Paul Gilmartin >Sent: Tuesday, April 4, 2023 9:36 PM > >On Tue, 4 Apr 2023 16:37:39 -0500, Charles Mills wrote: > >>I just had a similar problem: "how do you determine your entry R0 from C?" I >>asked here and got no answer. I had to front end the C with a tiny assembler >>program (57 lines including extensive comments; 11 executable instructions). >>Why did the C need its entry R0? Because it is called from Rexx, and needs to >>call IRXEXCOM, and so needs the Rexx environment block. >> >In: <https://www.ibm.com/docs/en/zos/2.5.0?topic=irxexcom-entry-specifications> >I read: > Register 0 > Address of an environment block (optional) >"optional" is intriguing. What are the other options? Must R0 point to >addressable >storage? The environment block begins with an identifier, CL8�ENVBLOCK�. >If the content of R0 doesn't match, is it simply ignored? > >Does C provide access to the entry RSA? If so, the STM 14,12,12(,13) leaves >R0 at RSA+20. > >But you still need to pass the IRXEXCOM to > >>Why the ^%$^%$#$^% do people come up with these non-standard linkages? Rexx >>passes a bunch of parameters -- why not pass the Environment Block address >>that way? >> >I think the REXX code germinated on CMS where there's less discipline. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
