Assembler-Course-CS 2011

Transkript

1 Assembler-Course-CS 2011, KSDM 612 Date: Version: 1.0 Final

2 Vorgeschichte Kurs war geplant als PC Kurs mit PC /370 + Bill Qualls Buch DOS Programme für PC /370 passen nicht ins CS-Umfeld PC /370 Exercises von DOS auf z/os kopiert 1. Kurstag enthält deshalb mehr Grundlagen-Informationen BP (Bonus Pack) privat von Don Krawacki Weitere Informationen zu Kurs im RZ1 TSO DKC Date: Slide 2

3 archaic... obsolete... complex... Why Assembler? difficult......not applicable for application programs...need much development time Date: Slide 3

4 timeless... within all z/os releases... 1:1 POP... Why Assembler? documented......for submodules and system-programs...need much development time but is very fast at execution Date: Slide 4

5 Assembler Advantages/Disadvantages Disadvantages development time ca x > PL/I Assembler is platform related (z/os / INTEL / Motorola usw.) Advantages very fast at execution time one assembly instruction = one OP-Code (POP) Dump-Analyze at z/os very easy nearly nothing is impossible! read z/os control blocks no runtime environment is necessary runs at all z/os systems PC370 (z/os-assembler-simulator for Window/DOS) better knowledge and understanding z/os Date: Slide 5

6 Assembler / one assembly instruction = one OP-Code Source of Pgm XXXXXX SR 15,15 = 1BFFx BR 14 = 07FEx Load within System-Storage 1BFF07FEx Date: Slide 6

7 Kursunterlagen und Dokumente Kursunterlagen Assembler Kurs (S) z/architecture Reference Summary (B) Assembler Bonus Pack (BP) (R) Dumps / Pgm-Sample (S) CS Assembler Richtlinien (S) Link zu PC /370 Assembler (-) S = Schwarz / R = Rot / B = Blau Date: Slide 7

8 Contents Kursziel Manuals & Documentation z/architecture Reference Summary Assembler Grundlagen Reentrant/Reusable + A-/R-Mode Base-Register Assembler Source/Object/Load Dynamic/Static Linkage Assembly/Linkage Editor Tips and Tricks z/os Control Blocks Establish the Base-Register Some Machine Instructions Linkage Conventions / Sample CS Assembler Richtlinien LE Language Environment DUMP Samples Date: Slide 8

9 Kursziel für bzw Assembler-Umfeld kennenlernen (POP / HLASM / Macros) Wo nachschauen? Wie erstelle ich Assembler-Programme? Einige Source-Programme Krawackis Muster Library + DKC Umgang mit PC /370 bzw. diese Exercises auf z/os Date: Slide 9

10 Manuals & Documentation IBM Manuals and other Documents List within BP-DVC/ASS last pages (V2 Page 136 ff) z/architecture Reference Summary Handout (B) Assembler Bonus Pack (BP) Handout (R) Don Krawackis Sample Library RZ1 TSO.KRA.SRC RZ1 TSO.KRA.* (other Samples) RZ1 DKC (Don Krawackis Course Appl) Date: Slide 10

11 z/architecture Reference Summary (Beilage Blau) Kurzzusammenfassung des POP als Hilfmittel (war früher als Reference Card im Umlauf) for this Course we use: Machine Instruction Formats Machine Instructions by Mnemonic Machine Instructions by Operation Code Assembler Instructions Program Interruption Codes PSW PC-Number Translation (PC Call) Access-Register Translation (Data-Spaces) Character Assignments Hexadecimal and Decimal Conversion Date: Slide 11

12 Assembler Grundlagen Registers (16 GPR today in POP as GR) 16 General Purpose Register / General Register (0 F bzw. R0 R15) 64 Bit Technical usage all for different things (see Linkage Conventions) except R0 Access Registers (16 AR) Urgent for Inter Address Space Communication 32 Bit Control Registers (16 CR) 16 Control Register (program event recording) 64 Bit Floating-Point Registers 16 Floating-Point Registers for floating-point instructions 64 Bit 3 different Addressing Modes 24 Bit / 31 Bit / 64 Bit see also the RMODE = Residency-Mode PSW (Program Status Word) PSW includes instruction address, condition code and other information Linkage Conventions See BP DVC/ASS Pages 7-12 Date: Slide 12

13 Reentrant/Reusable + Amode/Rmode In einigen Fällen ist es notwendig, dass ein Load-Module Reentrant/Reusable gelinkt wird, was einen Einfluss auf die Programmierung hat! Reentrant/Reusable = Daten und Programmcode sind getrennt! Da das z/os mit allen seinen Vorgängern "compatible" ist, gibt es drei verschiedene Addressing Modes (24 Bit / 31 Bit und 64 Bit) Im Assembler müssen wir das bei der Programmierung bereits berücksichtigen Weitere Informationen vom BP see Reentrant/Reusable + A-/R- Modes V2 Pages 7 ff Date: Slide 13

14 Base-Register One of the 16 GPR must be defined as Base-Register (maybe more than one depends of the length of the program) The Base-Register must hold the address of the CSECT (Control Section Program-Code) and can only address 4096 Bytes of Code! It is dangerous to modify the Base-Register after initialization! Use a Register between R3 and R11! Date: Slide 14

15 Assembler Source/Object/Load Program Source Readable (FB / normal PDS or PDSE) Pgm-Name can be Member-Name (max 8 Bytes) Copy-Member and Macros (max 8 Bytes) Program Object Normal Object Code (FB) Program Load Load-Library (U) ev. APF-Library Assembly-Listing SYSPRINT or DS/PDS/PDSE RC 0 in HLASM is optimal Date: Slide 15

16 Dynamic/Static Linkage Some Pages from BP see Overview BP DVC/ASS V2 Page 109 ff Date: Slide 16

17 Assembly/Linkage Editor Assembly and Linkage Editor is also under the BP See BP DVC/ASS V2 Page 123 ff Date: Slide 17

18 Tips and Tricks Tips and Tricks from BP (- BP DVC/ASS V2 Page 126 ff) Date: Slide 18

19 z/os Control Blocks Within Assembler-Code you can use DSECTs for accessing z/os Control Blocks (see also BP DVC/ASS V2 Page 129 ff) Date: Slide 19

20 Establish the Base-Register How do I establish a Base-Register Some samples within BP DVC/ASS V2 Pages 84 ff Date: Slide 20

21 Some Machine Instructions LA Load Address RX (also used to add values !) BP DVC/ASS Pages 4 L Load RX (Load a Value into Reg) L R1,WORD5 = 5810 A238 (RX ILC = 4) 58 = OP / 1 = R1 / 0 = no Index-R / A = Base-R / 238 = Displacement to WORD5 MVC Move Character SS(1) (Copy WORDB to WORDA) MVC WORDA,WORDB = D2DF A124 A3C8 (SS ILC = 6) D2 = OP / DF = Length ( = 224) / A = Base-R1 / 124 = Displ1 / A = B2 / 3C8 = D2 BALR Branch and Link Reg 05 (RR) BASR Branch and Save Reg 0D (RR) BAKR Branch and Stack Reg B240 (RRE) See BP DVC/ASS Page 71 Instruction Length > ILC depends on OP-Code! > see S0C1! OP-Codes 00 3F = 2 / 40 BF = 4 / C0 FF = 6 Date: Slide 21

22 Linkage Conventions Sample Sample Linkage Conventions within BP DVC/ASS V2 Page 20 ff Date: Slide 22

23 CS Assembler Handbuch Verbindliche Richtlinien Dokument macht Aussagen, dass jedes Assembler-Programm, welches von PL/I aufgerufen wird, LE-konform geschrieben werden muss (ist nicht mehr zeitgemäss!) Register Konventionen (Linkage Conventions) enthält Base register R11 (R11 muss auch unter LE nicht zwingend das Basis-Register sein) Dokument bei Kurs-Unterlagen Date: Slide 23

24 LE Language Environment Part over LE within BP DVC/ASS V2 Page 101 ff Date: Slide 24

25 DUMP Samples / Ausblick DUMP Samples / je nach Zeit-Fortschritt hätte ich noch einige Dumps! Ausblick Dies war der theoretische Kursteil nun kommt die Praxis Try and Error Kursteil B Bill Qualls PC /370 Assembler Download Buch von Bill Qualls Aufbau Exercises mit DKC Exercises auf z/os Ziel etwas Routine mit Assembler Termin: 30. September 2011 Fragen an Don Krawacki Infos auf DKC Date: Slide 25

26 Thanks for your attention! Have fun with assembler-programming! Date: Slide 26