111 lines
1.1 KiB
ArmAsm
111 lines
1.1 KiB
ArmAsm
;
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; filter.s
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; md2teach
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;
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; Created by Jeremy Rand on 2021-05-12.
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; Based on bfish_asoft by Kelvin Sherlock.
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;
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mcopy filter.macros
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keep filter
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offset_fileName gequ 10
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; SFFilter
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;
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; in stack:
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;
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; (3) |rtl
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; |----
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; (4) |DirEntryRecPtr
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; |----
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; (2) |returnval
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; |----
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; |.........
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; out stack:
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;
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; |returnval
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; |----
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; |.........
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;
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; Returns 0 if it's not an markdown file, or 4 if it is.
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;
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filter start
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_d equ 1
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ptr equ 5
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_rtlb equ 7
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DirPtr equ 11
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retval equ 15
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phb ;even up the stack
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phd
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pha
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pha
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tsc
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tcd
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stz <retval ;; assume no
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ldy #offset_fileName
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lda [<DirPtr],y
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sta <ptr
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iny
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iny
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lda [<DirPtr],y
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sta <ptr+2
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lda [<ptr]
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cmp #4
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blt exit
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tay
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short m
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dey
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lda [<ptr],y
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cmp #'d'
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beq checkM
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cmp #'D'
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bne noMatch
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checkM anop
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dey
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lda [<ptr],y
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cmp #'m'
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beq checkDot
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cmp #'M'
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bne noMatch
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checkDot anop
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dey
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lda [<ptr],y
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cmp #'m'
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bne noMatch
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long m
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lda #4
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sta <retval ;; I handle it
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bra exit
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noMatch anop
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long m
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exit anop
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pla
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pla
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pld
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pla
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sta 3,s
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pla
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sta 3,s
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plb
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rtl
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end
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