105 lines
2.1 KiB
ArmAsm
105 lines
2.1 KiB
ArmAsm
.include "../inc/common.inc"
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.export parse_dotted_quad
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.export dotted_quad_value
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.bss
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dotted_quad_value: .res 4 ; set to 32 bit ip address on a succesful call to parse_dotted_quad
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.data
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; self modifying code
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dotted_quad_ptr:
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lda $FFFF
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rts
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.code
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; convert a string representing a dotted quad (IP address, netmask) into 4 octets
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; inputs:
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; AX= pointer to null-terminated (*) string containing dotted quad
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; e.g. "192.168.1.0",0
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; outputs:
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; carry flag is set if there was an error, clear otherwise
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; dotted_quad_value: will be set to (32 bit) ip address (if no error)
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; (*) NB to assist with url parsing, a ':' or '/' can also terminate the string
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parse_dotted_quad:
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stax dotted_quad_ptr+1
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ldx #0
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txa
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sta dotted_quad_value
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@each_byte:
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jsr get_next_byte
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cmp #0
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beq @done
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and #$7F ; turn off bit 7
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cmp #'.'
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beq @got_dot
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cmp #':'
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beq @done
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cmp #'/'
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beq @done
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sec
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sbc #'0'
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bcc @error
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cmp #10
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bcs @error
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clc
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ldy #10
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@mul_by_y:
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adc dotted_quad_value,x
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bcs @error
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dey
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bne @mul_by_y
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sta dotted_quad_value,x
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jmp @each_byte
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@got_dot:
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inx
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cpx #4
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beq @error
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lda #0
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sta dotted_quad_value,x
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jmp @each_byte
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@done:
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cpx #3
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bne @error
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clc
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rts
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@error:
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sec
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rts
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get_next_byte:
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jsr dotted_quad_ptr
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inc dotted_quad_ptr+1
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bne :+
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inc dotted_quad_ptr+2
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: rts
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; -- LICENSE FOR dottedquad.s --
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; The contents of this file are subject to the Mozilla Public License
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; Version 1.1 (the "License"); you may not use this file except in
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; compliance with the License. You may obtain a copy of the License at
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; http://www.mozilla.org/MPL/
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;
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; Software distributed under the License is distributed on an "AS IS"
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; basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
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; License for the specific language governing rights and limitations
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; under the License.
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;
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; The Original Code is ip65.
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;
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; The Initial Developer of the Original Code is Jonno Downes,
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; jonno@jamtronix.com.
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; Portions created by the Initial Developer are Copyright (C) 2009
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; Jonno Downes. All Rights Reserved.
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; -- LICENSE END --
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