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60 lines
1.1 KiB
ArmAsm
60 lines
1.1 KiB
ArmAsm
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; Ullrich von Bassewitz, 21.7.2000
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;
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; Add a block to the heap free list
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;
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; void __fastcall__ _hadd (void* mem, size_t size);
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;
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;
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.importzp ptr1, ptr2
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.import popax
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.import hadd
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.export _hadd
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.macpack generic
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; Offsets into struct freeblock and other constant stuff
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size = 0
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next = 2
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prev = 4
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admin_space = 2
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min_size = 6
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; Code
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_hadd: sta ptr1 ; Store size in ptr1
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stx ptr1+1
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jsr popax ; Get the block pointer
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sta ptr2
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stx ptr2+1 ; Store block pointer in ptr2
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; Check if size is greater or equal than min_size. Otherwise we don't care
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; about the block (this may only happen for user supplied blocks, blocks
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; from the heap are always large enough to hold a freeblock structure).
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lda ptr1 ; Load low byte
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ldx ptr1+1 ; Load/check high byte
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bne @L1
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cmp #min_size
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bcs @L1
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rts ; Block not large enough
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; The block is large enough. Set the size field in the block.
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@L1: ldy #size
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sta (ptr2),y
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iny
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txa
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sta (ptr2),y
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; Call the internal function since variables are now setup correctly
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jmp hadd
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