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   1 ;
   2 ; loadlocal.s
   3 ;
   4 ; Loading and initialising extension DLLs
   5 ;
   6 ; © 1994 Straylight
   7 ;
   8
   9 ;----- Standard stuff -------------------------------------------------------
  10
  11                 GET     libs:header
  12                 GET     libs:swis
  13
  14 ;----- Other external dependencies ------------------------------------------
  15
  16                 IMPORT  |x$stack_overflow|
  17                 IMPORT  malloc
  18                 IMPORT  free
  19                 IMPORT  |_dll_giveMemory|
  20
  21 ;----- Main code ------------------------------------------------------------
  22
  23                 AREA    |DLL$$Code|,CODE,READONLY
  24
  25 ; dll _dll_loadExtension(char *name)
  26
  27                 EXPORT  |_dll_loadExtension|
  28 |_dll_loadExtension|
  29 dle             ROUT
  30
  31                 ; --- APCS header ---
  32
  33                 MOV     ip,sp
  34                 STMFD   sp!,{v1-v3,fp,ip,lr,pc}
  35                 SUB     fp,ip,#4
  36                 CMP     sp,sl
  37                 BLLT    |x$stack_overflow|
  38
  39                 ; --- Find the size of the DLL file ---
  40
  41                 MOV     v3,a1                   ;Look after the name pointer
  42                 MOV     a2,a1                   ;Pass filename to OS_File
  43                 MOV     a1,#17                  ;Load, no path variable
  44                 SWI     XOS_File                ;Find information about DLL
  45                 BVS     %10dle                  ;If it failed, return 0
  46                 CMP     a1,#1                   ;Check that it's a file
  47                 BNE     %10dle                  ;If not, return failure
  48
  49                 ; --- Allocate a block for the DLL ---
  50
  51                 ADD     a1,v1,#20               ;Allocate an extra 20 bytes
  52                 BL      malloc                  ;Allocate the workspace
  53                 CMP     a1,#0                   ;Did it work?
  54                 BEQ     %10dle                  ;No -- return failure
  55                 MOV     v2,a1                   ;Look after this pointer
  56
  57                 ; --- Load the DLL into the block ---
  58
  59                 MOV     a2,v3                   ;Point to DLL name
  60                 SWI     XDLL_Load               ;Load the DLL into memory
  61                 BVS     %11dle                  ;If it failed, free the block
  62
  63                 ; --- Allocate workspace for the DLL ---
  64
  65                 MOV     a1,v2                   ;Point to the DLL
  66                 SWI     XDLL_Info               ;Find information about it
  67                 MOV     a1,v1                   ;Allocate the right amount
  68                 BL      malloc                  ;Allocate some workspace
  69                 CMP     a1,#0                   ;Ensure that it worked
  70                 BEQ     %11dle                  ;Kill everything if it failed
  71                 MOV     a2,a1                   ;Set up workspace pointer
  72                 MOV     a1,v2                   ;Point to DLL
  73                 SWI     XDLL_SetInstanceVars    ;Give it the memory
  74
  75                 ; --- Allocate space for any other DLLs loaded ---
  76
  77                 BL      |_dll_giveMemory|       ;Allocate space for new DLLs
  78
  79                 ; --- Return the DLL handle to the caller
  80
  81                 MOV     a1,v2                   ;Put the handle away nicely
  82                 LDMDB   fp,{v1-v3,fp,sp,pc}^    ;Return to caller
  83
  84                 ; --- Free DLL block and return to caller ---
  85
  86 11dle           MOV     a1,v2                   ;Point to DLL block
  87                 BL      free                    ;Free the memory it used
  88
  89                 ; --- Return to caller with tail between legs ---
  90
  91 10dle           MOV     a1,#0                   ;Return a NULL pointer
  92                 LDMDB   fp,{v1-v3,fp,sp,pc}^    ;Return to caller
  93
  94                 LTORG
  95
  96 ; void _dll_freeExtension(dll d)
  97
  98                 EXPORT  |_dll_freeExtension|
  99 |_dll_freeExtension|
 100
 101                 MOV     ip,sp
 102                 STMFD   sp!,{v1,fp,ip,lr,pc}
 103                 SUB     fp,ip,#4
 104                 CMP     sp,sl
 105                 BLLT    |x$stack_overflow|
 106
 107                 MOV     v1,a1
 108                 SWI     DLL_FindInstanceVars
 109                 BL      free
 110                 MOV     a1,v1
 111                 LDMDB   fp,{v1,fp,sp,lr}
 112                 B       free
 113
 114                 LTORG
 115
 116 ;----- That's all, folks ----------------------------------------------------
 117
 118                 END