---------- Original Message ---------- From: Joe Monk <joemon...@gmail.com> To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Using AN EAX value of PC Routineto index into the Authority Table Date: Sat, 18 Jul 2020 20:27:39 -0500
This is explained on page 113: "The example also shows the difference between cross memory data movement with a move to primary (MVCP) and a data movement performed through ARs and the MVC instruction. PGM1 uses the SSAR instruction to establish AS2 as the secondary address space, then it uses MVCP to move data from AS2 to AS1. PCRTN issues the SAC instruction to change the ASC mode to AR mode. Having loaded the addresses and ALETs into the AR/GPR correctly, PCRTN uses MVC to move data from AS2 to AS1." Joe On Sat, Jul 18, 2020 at 1:56 PM esst...@juno.com <esst...@juno.com> wrote: > Hello. I’m reading Chapter 5 Using Access Registers in MVS > Programming Extended Addressability Guide (SA23-1394-30). Pages 113 – > 116 “Procedures for establishing addressability to an address > space”Regarding Figure 38I understand the EAX value of PCRTN indexes > into the AT of AS2.I understand PC routine contains an ALESERV ADD request > for an address spaceI understand Issuing the ETDEF macro to build the PC > routine's ETD with the EAX parameter code.It’s the Target Address > Space (AS2) that I have issues with.First of all – I am assuming > PCRTN resides in the Private Area of the Accessing Address Space (AS1) and > PCRTN is defined as a Non- Space Switching, Stacking PC , with a System LX. > Is My understanding correct ?.Second - if AS2 (The Target Address space) > can switch to Supervisor State, issue ATSET and a Cross Memory Post why > can’t it simply Establish and Setup Its Own Cross Memory Environment, > allowing AS1 or any other Address Space the capability of issuing a PC > calls to it directly ? The procedure described for AS2 in Figure 38 seems > un-necessary to me..Third – Given the technique described for Figure > 38 – wouldn’t it be more appropriate for AS1 to define two > Non-Space Switching PC routines. One residing in the Private Area of AS1, > and the other in LPA. This would allow AS2 to PC to the second PC routine > (in LPA) to issue ATSET and a Cross Memory POST. Does this make better > sense?.Fourth – is any one on this discussion list aware of any IBM > product, or OEM Vendor product, or installation written software, that uses > the technique described with Figure 38 ?.Paul D’Angelo. > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
