mirror of https://github.com/hsoft/collapseos.git
37 lines
577 B
NASM
37 lines
577 B
NASM
; mmap
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;
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; Block device that maps to memory.
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;
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; *** DEFINES ***
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; MMAP_START: Memory address where the mmap begins
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; Returns absolute addr of memory pointer in HL.
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_mmapAddr:
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push de
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ld de, MMAP_START
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add hl, de
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jr nc, .end
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; we have carry? out of bounds, set to maximum
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ld hl, 0xffff
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.end:
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pop de
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ret
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; if out of bounds, will continually return the last char
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; TODO: add bounds check and return Z accordingly.
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mmapGetC:
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push hl
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call _mmapAddr
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ld a, (hl)
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cp a ; ensure Z
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pop hl
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ret
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mmapPutC:
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push hl
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call _mmapAddr
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ld (hl), a
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cp a ; ensure Z
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pop hl
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ret
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