mdw@git.distorted.org.uk Git - ssr/blob - StraySrc/Libraries/Sapphire/sail/s/mem

   1 ;
   2 ; mem.s
   3 ;
   4 ; Generic memory allocation for TermScript
   5 ;
   6 ; © 1995 Straylight
   7 ;
   8
   9 ;----- Standard Header ------------------------------------------------------
  10
  11                 GET     libs:header
  12                 GET     libs:swis
  13
  14                 GET     libs:stream
  15
  16 ;----- External dependencies ------------------------------------------------
  17
  18                 GET     sh.errNum
  19                 GET     sh.error
  20
  21 ;----- Main code ------------------------------------------------------------
  22
  23                 AREA    |TermScript$$Code|,CODE,READONLY
  24
  25 ; --- mem_alloc ---
  26 ;
  27 ; On entry:     R0 == size of block to allocate
  28 ;
  29 ; On exit:      R0 == pointer to anchor for that block
  30 ;               May return an error
  31 ;
  32 ; Use:          Tries to allocate a block of memory, and returns a pointer
  33 ;               to the anchor for that block. All very unusual really,
  34 ;               but we blame Wimp_Extension which allocates anchors for
  35 ;               you in an utterley horrible way.
  36
  37
  38                 EXPORT  mem_alloc
  39 mem_alloc       ROUT
  40
  41                 ; --- For now, we will use the RMA ---
  42
  43                 STMFD   R13!,{R1-R3,R14}
  44                 ADD     R3,R0,#4
  45                 MOV     R0,#6
  46                 SWI     XOS_Module
  47                 BVS     %99mem_alloc
  48                 ADD     R3,R2,#4
  49                 STR     R3,[R2,#0]
  50                 MOV     R0,R2
  51                 LDMFD   R13!,{R1-R3,PC}^
  52
  53 99mem_alloc     MOV     R0,#err_noMem
  54                 B       error_report
  55
  56                 LTORG
  57
  58 ; --- mem_free ---
  59 ;
  60 ; On entry:     R0 == anchor of the block to free
  61 ;
  62 ; On exit:      --
  63 ;
  64 ; Use:          Frees the block.
  65
  66                 EXPORT  mem_free
  67 mem_free        ROUT
  68
  69                 STMFD   R13!,{R0-R2,R14}
  70                 LDR     R2,[R0,#0]
  71                 SUB     R2,R2,#4
  72                 MOV     R0,#7
  73                 SWI     OS_Module
  74                 LDMFD   R13!,{R0-R2,PC}^
  75
  76                 LTORG
  77
  78 ; --- mem_realloc ---
  79 ;
  80 ; On entry:     R0 == pointer to block anchor
  81 ;               R1 == new size requested
  82 ;
  83 ; On exit:      May return an error
  84 ;
  85 ; Use:          Resizes a block
  86
  87                 EXPORT  mem_realloc
  88 mem_realloc     ROUT
  89
  90                 MOV     R0,#err_realloc
  91                 B       error_report
  92
  93                 LTORG
  94
  95 ;----- That's all, folks ----------------------------------------------------
  96
  97                 END