Relocatable file format and method and apparatus for creating and loading same

90 Pages·2013·3.81 MB·English

USO05764987A
United States Patent [19] [11] Patent Number: 5,764,987
Eidt et a1. [45] Date of Patent: Jun. 9, 1998
[54] RELOCATABLE FILE FORMAT AND OTHER PUBLICATIONS
METHOD AND APPARATUS FOR CREATING
“IEEE Standard for Microprocessor Universal Format for
AND LOADING SAME
Object Modules (IEEE Std 695-1990)”. IEEE Computer
Society (Feb. 29. 1991).
[75] Inventors: Erik L. Eidt. Campbell; Alan W.
Braga. et al.. “A Portable Linking Loader". Symposium on
Lillich. Los Gatos. both of Calif.
Trends and Applications 1976: Micro and Mini Systems.
[73] Assignee: Apple Computer, Inc.. Cupertino. IEEE Computer Society (May 27. 1976). pp. 124-128.
Calif. Presser. Leon. and White. John R.. “Linkers and Loaders”.
ACM Computing Surveys (Sep. 1972). vol. 4. No. 3. pp.
149-167.
[21] Appl. No.: 654,013
(List continued on next page.)
[22] Filed: May 28, 1996
Primary Examiner—Daniel H. Pan
Related U.S. Application Data Attorney Agent, or Firm—Fliesler. Dubb. Meyer & Lovejoy
[57] ABSTRACT
163] Continuation of Ser. No. 212,153, Mar. 14, 1994, aban
doned, which is a continuation-impart of Ser No. 35,750,
Mar. 23, 1993. Relocation table entries in a executable object code ?le are
interpreted as relocation instructions rather than as indi
[5 1] 1m. (:1.6 ............................. .. G06F 9/44; G06F 12/02 vidual speci?cations for a particular respective relocatable
[52] U.S. Cl. .......... .. 395/701; 395f/10; 395/712 information item. An abstract machine is provided for inter
[5 3] Field of Search . ...................... .. 395/658. 375. preting the relocation instructions and performing various
395/42l.08. 157. 800. 775. 700. 601. 500. relocation operations and various control functions for the
183.14. 139. 412. 701. 200.61. 682. 200.79. abstract machine. in response to the relocation instructions.
868. 676. 684. 311. 826. 110. 710. 200.59. The abstract machine maintains certain variables containing
284. 830. 712. 650. 507. 404; 364/DIG. 1. information which is referenced and updated in response to
DIG. 2; 340/825. 28 certain types of the relocation instructions. thereby obviating
the need to include such information as part of each relo
[5 6] References Cited cation instruction. Certain of the relocation instruction types
can also specify a particular relocation operation to be
U.S. PA’I'EN'I‘ DOCUMENTS
performed on a run of n consecutive relocatable information
4,791,550 12/1988 Stevenson et a1. ................... .. 395/650 items. where n is speci?ed as part of the relocation instruc
4,881,168 11/1989 Imagami et a1. ...... .. 395/800 tion. Certain of these relocation instruction types also con
4,918,587 4/1990 Pechter et a1. .. 395/421.08 sider each information item as including two or more
4,924,515 5/1990 Matyas et a1. .... .. 380/25 individual relocations of the same or di?erent types to
5,175,856 12/1992 Van Dyke et a1. .. 395/700 perform. thus e?‘ectively specifying a run of n repetitions of
5,193,180 3/1993 Hastings ............ .. 395/575
a pattern of relocations. Other types of relocation instruc
5,291,601 3/1994 Sands ............ .. 395/700
tions are also made available. The ?le also contains a hashed
5,307,490 4/1994 Davison et a1. . 395/650
symbol export table and pattem-initialized data expansion
5,327,559 7/1994 Priven et a1. 395/700
instructions.
5,339,419 8/1994 Chanetal. .... .. 395/700
5,403,639 4/1995 Bdsan et a1. . 395/600
5,408,665 4/1995 Fitzgerald ............................. .. 395F700 58 Claims, 14 Drawing Sheets
f 102 105 x 108 X
DISK
CPU MEMORY DRIVE
104/
5,764,987
Page 2
OTHER PUBLICATIONS Proceedings of the 1986 International Conference on Indus
trial Electronics. ConlIol and Instrumentation (Sep. 29.
"The Concise Atari ST 68000 Programmer’s Reference
1986). vol. 2 of 2. pp. 839-844.
Guide”. Glentop Publishers (Aug. 1986). pp. 2-20 - 2-27.
“SCO® UN1X® Development System. Programmer‘s Ref ‘inter-Linkage Function Invocation Method". IBM Techni
erence Manual vol. 1". SCO Open Systems Software (10 cal Disclosure Bulletin (Sep. 1992). vol. 35. No. 4B. pp.
Dec. 1991).pp. 180-186. 294-299. 337.351-354.369-372. 44-49.
“R6000 InfoExplorer”. Articles Published on CD-ROM: “EXE Format for 32-Bit Personal Computer Systems". IBM
IBM Corporation. 1991. Articles entitled: a.out File Format; Technical Disclosure Bulletin (Sep. 1992). vol. 34. No. 3.
Optional Auxiliary Header for the a.out File; Section Head pp. 363-365.
ers for the a.out File; Raw Data Sections for the a.out File;
Garitagoitia. JR. et al.. “Relocating Direct Linking Loader
Special Data Sections for the a.out File; Relocation Infor
for MCS-80 Microcomputer Series". Euromicro Newsletter
mation for the a.out File; xcolih; ?lehdnh; reloch; scnhdrh;
(1977). vol. 3. No. 3. pp. 22-28.
loader.h.
Kanai. et al.. “The Concept and Implementation of Standard Duncan. Ray. “Advanced OS/2 Programming”. Microsoft
Object Module Format for Microprocessors (SYSROF-E)”. Press (1989). Appendix D. pp. 715-736.
US. Patent Jun. 9, 1998 Sheet 1 of 14 5,764,987
102 105
/ 1 JOHN
DISK
CPU MEMORY DRIVE
104/ FIG 1
[106
312
DATA SECTION 1 /
READ/ /324
wRITE DATA SECTION 2
READ APPLICATION PROGRAM [304
ONLY HEADER 1 305
CODE SECTION 1 /308 303
DATA SECTION 1 /_m
LOADER SECTION 1 /
LIBRARY CONTAINER 315
HEADER 2 /318
CODE SECTION 2 / 320 314
DATA SECTION 2 /322
LOADER SECTION 2 /
FIG. 3
US. Patent Jun. 9, 1998 Sheet 2 of 14 5,764,987
LOAD CONTAINER
/ 204
LOAD ENITIRE CONTAINER INTO READ ONLY MEMORY
IF NOT ALREADY LOADED BY ANOTHER TASK
/'205
ALLOCATE AND FILL READ\WRITE MEMORY FOR DATA
AND PIDATA SECTION USING SECTION HEADERS AND
SECTION DATA PORTIONS OF PRESENT CONTAINER;
CREATE REGIONS TABLE FOR PRESENT
CONTAINER, INDICATING VIRTUAL START ADDRESS
FOR EACH SECTION i IN PRESENT CONTAINER
[208
RESOLVE IMPORTS
2.14
ANY MORE
LOADABLE
SECTIONS?
210
/_
PERFORM RELOCATIONS ON NEXT SECTION
[215
INCREMENT i
FIG. 2
US. Patent Jun. 9, 1998 Sheet 3 of 14 5,764,987
208
‘ RESOLVE IMPORTS ,
ANY ENTRIES 404
REMAINING IN TABLE
OF IMPORT CONTAINER
IDs?
405
/
RECURSIVELY LOAD CONTAINER FOR NEXT IMPORT
CONTAINER
408
ANY IMPORT
SYMBOLS REMAINING
FOR THIS IMPORTED
CONTAINER?
/4.10
FIND NEXT IMPORT SYMBOL NAME (FROM IMPORT
SYMBOL TABLE OF IMPORTING CONTAINER) IN
EXPORT SYMBOL TABLE OF IMPORTED CONTAINER
CALCULATE VIRTUAL ADDRESS OF THIS SYMBOL AND
STORE AS IMPORTS (1'). WHERE j 15 THE SYMBOL
NUMBER AS SEEN BY THE IMPORTING CONTAINER
[4.14 \-412
INCREMENT SYMBOL NUMBER j
FIG. 4
US. Patent 5,764,987
Jun. 9, 1998 Sheet 4 of 14
ERROR CHECKING
INITIALIZE ABSTRACT MACHINE VARIABLES
ANY MORE
RELOCATION INSTRUCTIONS
IN THIS SECTION‘?
[510
COPY CURRENT RELOCATION INSTRUCTIOIN
[512
INCREMENT RELOC BY 2 BYTES
514
SWITCH
OPCODE
515 520
I 51h 52A 524 525\ /
com: DATA DESC oscz VTBL SYMR
534
II 53% 53m /532 [535 H525
DDAT SYMB 001s nus SECN DELTA
I I I I I I
5401 54A 5441 54m
RPT LABS LSYM LRPT LSECS DEFAULT
5491 550i
FIG. 5

US. Patent Jun. 9, 1998 Sheet 6 0f 14 5,764,987
15 13 12 9 8 0
O 1 O SUBOP4 CNTQ RUN
FIG. 7A
1 0 0 0 B12 DELTA
FIG. 7B
15 13 12 9 8 0
O 1 1 SUBOP4 IDXQ GLP
FIG. 7C
15 14 13 6 5 O
O 0 W8 N6 DELTADATA
FIG. 70
15 12 11 B 7 O
1 O 0 1 I4 CNTB RPT
28 27 26 25 O
SUB
O 1 0 OPC OFFSET26
FIG. 7F
28 27 2s 2s 22 21 o
01 1 SUB- CNT4- 011122
OPC
FIG. 76‘
US. Patent Jun. 9, 1998 Sheet 7 0f 14 5,764,987
FIND NEXT IMPORT SYMBOL NAME (FROM IMPORT
SYMBOL TABLE OF IMPORTING CONTAINER) IN
EXPORT SYMBOL TABLE OF IMPORTED CONTAINER
410
COMPUTE THE HASHWORD VALUE /_802
FOR THE SYMBOL NAME
e04
COMPUTE THE SLOT NUMBER /
FOR THE EXPORT SYMBOL
[805
FETCH THE CHAIN COUNT AND THE EXPORT CHAIN TABLE
INDEX OF THE FIRST EXPORT CHAIN TABLE ENTRY FOR
THE SLOT, USING THE HASH SLOT NUMBER AS AN INDEX
INTO THE EXPORT SLOT TABLE
[808
LOOP THROUGH THE EXPORT CHAIN TABLE
STARTING FROM THE INDEX PREVIOUSLY FETCHED
8.10
DOES
THE HASHWORD
FOR THE CURRENT ENTRY MATCH THAT
COMPUTED FOR THE DESIRED EXPORT
SYMBOL’?
/-B12
APPLY THE EXPORT CHAIN TABLE INDEX OF THAT HASHWORD
TO THE EXPORT SYMBOL TABLE TO OBTAIN THE OFFSET
TO THE EXPORT NAME'S TEXT IN LOADER STRING TABLE
814
DOES
THE LOADER STRING TABLE NO
ENTRY MATCH THE DESIRED
EXPORT SYMBOL
NAME‘?
FIG. 8
US. Patent 5,764,987
Jun. 9, 1998 Sheet 8 of 14
( XCOFF-TO-PEF)
INITIALIZATION
CONVERT SYMBOLS
SORT PEF EXPORT SYMBOLS
CONVERT RELOCATIONS TO
PEF RELOCATION INSTRUCTIONS
/910
PACK DATA
/912
COMPUTE OFFSETS
AND FILL HEADERS
/-914
WRITE PEF FILE
( DONE )
FIG. 9