65 lines
1019 B
ArmAsm
65 lines
1019 B
ArmAsm
;
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; common iocb setup routine for read, write
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; expects __fastcall__ parameters (int fd, void *buf, int count)
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;
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.include "atari.inc"
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.include "errno.inc"
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.import popax
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.import __oserror
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.import fdtoiocb
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.export __rwsetup
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__rwsetup:
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pha ; push size in stack
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txa
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pha
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jsr popax ; get buffer address
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pha
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txa
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pha
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jsr popax ; get handle
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jsr fdtoiocb ; convert to iocb
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bmi iocberr ; negative (X=$FF or A>$7F) on error.
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tax
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pla ; store address
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sta ICBAH,x
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pla
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sta ICBAL,x
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pla ; store length
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sta ICBLH,x
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pla
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sta ICBLL,x
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ora ICBLH,x ; returns Z if length is 0
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rts
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iocberr:pla
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pla
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pla
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pla
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ldx #$FF ; indicate error + clear ZF
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rts
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;
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; this routine updates errno. do a JMP here right after calling
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; CIOV. we expect status in Y.
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;
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.export __do_oserror,__inviocb
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__do_oserror:
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sty __oserror ; save os dependent error code
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retminus:
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lda #$FF
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tax ; return -1
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rts
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;
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; sets EINVAL error code and returns -1
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;
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__inviocb:
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lda #<EINVAL
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jsr __seterrno
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jmp retminus ; return -1
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