I inserted a DC H’0’ At the begining of a rmode64 pgm to look at the register values and register 15 didn’t have the entry point
> On Aug 17, 2025, at 11:04 AM, Seymour J Metz <[email protected]> wrote: > > Standard linkage is different for AMODE24/31 and AMODE64. An RMODE64 program > should expect R15 to have flag rather than the EP address. > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > עַם יִשְׂרָאֵל חַי > נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר > > > > > ________________________________________ > From: IBM Mainframe Discussion List <[email protected]> on behalf of > Joe Monk <[email protected]> > Sent: Sunday, August 17, 2025 11:00 AM > To: [email protected] <[email protected]> > Subject: Re: RMODE 64 > > > External Message: Use Caution > > > Standard linkage > > Joe > >> On Sun, Aug 17, 2025 at 9:52 AM Joseph Reichman < >> [email protected]> wrote: >> >> My only question is when submitting a batch job to execute rmode 64 what >> is the value >> >> Of Register 15 in entry >> >>> On Aug 17, 2025, at 10:32 AM, Peter Morrison < >> [email protected]> wrote: >>> >>> People, >>> >>> >>> >>> I have watched this discussion for several days. I thought I would weigh >>> in. I have created and executed programs in RMODE 64. >>> >>> >>> >>> RMODE 64 has been supported by z/OS for a long time. I am not sure what >>> level it came in with (someone else can provide that) but all the >> relevant >>> items have been changed, as mentioned below. >>> >>> >>> >>> Note that before I begin to list things, to execute in an RMODE 64 >>> environment (i.e., located above the 'bar') you *MUST* be in AMODE 64 (if >>> you are not sure why, please read the principles of operation. You *MUST* >>> also remain in AMODE 64 for as long as the code that is being executed is >>> above the bar. >>> >>> >>> >>> * You can use the assembler to create a CSECT that can be loaded >>> into 64-bit storage by using the '<csectname> RMODE 64' statement. >>> >>> >>> >>> * There is no specific 'xD' ESD entry. Instead, the object format >>> has been enhanced to add a bit to the flags field in the ESD which says >> 'add >>> 4 to the length of the field'. Thus VD and external AD fields can be >>> handled. Similarly, the object RLD records also have a flag bit that says >>> 'add 4 to the length - allowing an RLD entry for an 8-byte xD. Note that >> you >>> do not need to use GOFF to have RMODE 64 CSECTs. >>> >>> >>> >>> * When you bind (link-edit) the program, you can specify the >> binder >>> option via the JCL Parm field (you can also use an input option, not >>> discussed here, read the manual). *DO NOT* use 'RMODE=64'. Instead you >>> *MUST* specify 'RMODEX=64TRUE'. Don't ask me why (RTFM). The resulting >>> program is an RMODE64 program. >>> >>> >>> >>> * Note that an RMODE 64 program *DOES NOT* have to be a program >>> object. The load module format in a PDS (not a PDSE) has been enhanced, >> The >>> RMODE in the directory entry has a RMODE64 bit, the CESD entry flags in >> the >>> actual load module have a 'add 4 to the length' bit, and the RLD entry >> flags >>> in the actual load module have a 'add 4 to the length' bit. >>> >>> >>> >>> * Program management was enhanced to load RMODE 64 programs above >>> the bar. The CDE (still in 24-bit storage) will point to a CDX which >> point >>> to a 64-bit extent list, which has 8-byte addresses and lengths. >>> >>> >>> >>> * The ATTACH[X], LINK[X], XCTL[X], and LOAD facilities all can >> load >>> RMODE 64 programs. Whether the parameter list passed to that program >> will be >>> correct is another matter (note that the parameter list format depends on >>> the AMODE, not the RMODE) - the system doesn't alter the passed R1 value >> so >>> you probably need to specify the correct parameter list format - >> determining >>> the target's RMODE (or AMODE) will be fun! (you can't use BLDL, because >> the >>> target program could be in the DLPA). I don't know what happens (IPL >> wait or >>> ignored) if an RMODE 64 program that is put into PLPA (or MLPA or FLPA) - >>> there is no 64-bit xLPA (the DLPA can have RMODE 64 programs in it but >> is >>> not built during IPL) and the compressed extent list in the LPDE does not >>> have 8-byte addresses and lengths. Note that all RMODE 64 programs >> *MUST* be >>> AMODE 64 but the reverse isn't true. (the parameter list format is based >> on >>> the AMODE of the target, not the RMODE) >>> >>> >>> >>> * The JCL EXEC statement can execute an RMODE 64 program by >> simply >>> specifying its name. I don't know whether or not the PARMS passed are in >> the >>> correct format for a AMODE 64 program (does anyone want to test that?). >>> Under the covers the EXEC statement uses ATTACH[X]. >>> >>> >>> >>> This list doesn't cover everything, but hopefully covers the main things. >>> >>> >>> >>> It's pretty easy to make a program execute in RMODE 64 (as mentioned >> above, >>> you *MUST* be in AMODE 64). However, as others have mentioned, only some >>> system services allow a user to be in AMODE 64, and even fewer allow a >> user >>> to be located above the bar (i.e., RMODE 64). The safest rule is to >> assume >>> the AMODE64 and RMODE 64 code cannot use a service unless that service >>> explicitly says it can. >>> >>> >>> >>> Peter Morrison >>> >>> >>> >>> >>> ---------------------------------------------------------------------- >>> For IBM-MAIN subscribe / signoff / archive access instructions, >>> send email to [email protected] with the message: INFO IBM-MAIN >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, >> send email to [email protected] with the message: INFO IBM-MAIN >> > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > > > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
