nes-proj/cpu/z80/uip_arch.c

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/*
* Copyright (c) 2007, Takahide Matsutsuka.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
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* $Id: uip_arch.c,v 1.2 2007/09/29 03:57:39 matsutsuka Exp $
*
*/
/*
* \file
* Z80 architecture-depend uip module
* for calculating checksums
* \author
* Takahide Matsutsuka <markn@markn.org>
*/
#include <stddef.h>
#include "uip_arch.h"
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static const u16_t sizeof_uip_ipaddr_t = sizeof(uip_ipaddr_t);
static const u16_t offset_tcpip_hdr_len = offsetof(struct uip_tcpip_hdr, len);
static const u16_t offset_tcpip_hdr_srcipaddr = offsetof(struct uip_tcpip_hdr, srcipaddr);
/*--------------------------------------------------------------------------*/
static void upper_layer_chksum() {
__asm
;; ---------------------------------
;; static u16_t upper_layer_chksum(u8_t proto);
;; Stack; retl reth
;; @param C proto
;; ABCDEHL____
;; ---------------------------------
;; HL = BUF = &uip_buf[UIP_LLH_LEN]
ld hl, #_uip_buf
ld de, #UIP_LLH_LEN
add hl, de
push hl
;; HL = BUF->len[0]
push ix
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ld ix, #_offset_tcpip_hdr_len
ld e, 0(ix)
ld d, 1(ix)
add hl, de
pop ix
;; DE = upper layer length
ld d, (hl)
inc hl
ld e, (hl)
#if UIP_CONF_IPV6
#else
ld a, e
sub a, #UIP_IPH_LEN
ld e, a
jr nc, _upper_layer_chksum_setlen2
dec d
_upper_layer_chksum_setlen2:
#endif
;; bc = upper_leyer_len + proto
ld b, d
ld a, e
add a, c
ld c, a
jr nc, _upper_layer_chksum_setlen3
inc b
_upper_layer_chksum_setlen3:
pop hl ; BUF
push de
push ix
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ld ix, #_offset_tcpip_hdr_srcipaddr
ld e, 0(ix)
ld d, 1(ix)
add hl, de
ld e, l
ld d, h
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ld ix, #_sizeof_uip_ipaddr_t
ld l, 0(ix)
ld h, 1(ix)
pop ix
sla l
rl h
push hl
push de
push bc
call _uip_arch_chksum ; hl = sum
pop af
pop af
pop af
;; de is still stacked
ld b, h
ld c, l
ld hl, #_uip_buf
ld de, #UIP_IPH_LEN
add hl, de
_upper_layer_chksum_call:
ld de, #UIP_LLH_LEN
add hl, de
push hl
push bc
call _uip_arch_chksum
pop af
pop af
pop af
ld a, h
or a, l
jr nz, _upper_layer_htons
ld hl, #0xffff
jr _upper_layer_ret
_upper_layer_htons:
ld a, l
ld l, h
ld h, a
_upper_layer_ret:
__endasm;
}
/*--------------------------------------------------------------------------*/
u16_t
uip_ipchksum(void)
{
__asm
;; ---------------------------------
;; u16_t uip_ipchksum(void);
;; Stack; retl reth
;; ABCDEHL____
;; return HL
;; ---------------------------------
ld hl, #UIP_IPH_LEN
push hl
;; HL = BUF = &uip_buf[UIP_LLH_LEN]
ld hl, #_uip_buf
;; BC = sum = 0
ld bc, #0
jp _upper_layer_chksum_call
__endasm;
}
/*--------------------------------------------------------------------------*/
#if UIP_CONF_IPV6
u16_t
uip_icmp6chksum(void)
{
__asm
;; ---------------------------------
;; u16_t uip_icmp6chksum(void);
;; Stack; retl reth
;; ABCDEHL____
;; return HL
;; ---------------------------------
ld c, #UIP_PROTO_ICMP6
jp _upper_layer_chksum
__endasm;
}
#endif /* UIP_CONF_IPV6 */
/*--------------------------------------------------------------------------*/
u16_t
uip_tcpchksum(void)
{
__asm
;; ---------------------------------
;; u16_t uip_tcpchksum(void);
;; Stack; retl reth
;; ABCDEHL____
;; return HL
;; ---------------------------------
ld c, #UIP_PROTO_TCP
jp _upper_layer_chksum
__endasm;
}
/*--------------------------------------------------------------------------*/
#if UIP_UDP_CHKSUMS
u16_t
uip_udpchksum(void)
{
__asm
;; ---------------------------------
;; u16_t uip_udpchksum(void);
;; Stack; retl reth
;; ABCDEHL____
;; return HL
;; ---------------------------------
ld c, #UIP_PROTO_UDP
jp _upper_layer_chksum
__endasm;
}
#endif /* UIP_UDP_CHKSUMS */
/*--------------------------------------------------------------------------*/