mirror of https://github.com/digarok/gsplus.git
153 lines
3.4 KiB
C
153 lines
3.4 KiB
C
/*
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GSPLUS - Advanced Apple IIGS Emulator Environment
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Based on the KEGS emulator written by Kent Dickey
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See COPYRIGHT.txt for Copyright information
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See LICENSE.txt for license (GPL v2)
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*/
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/* This is an interface between the SCC emulation and the LAP bridge. */
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#include <stdbool.h>
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#include "defc.h"
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#include "scc.h"
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int g_appletalk_bridging;
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int g_appletalk_turbo = 0;
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int g_appletalk_diagnostics = 0;
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int g_appletalk_network_hint = 0;
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#ifdef HAVE_ATBRIDGE
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#include "atbridge/atbridge.h"
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#include "atbridge/llap.h"
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extern Scc scc_stat[2];
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extern int g_config_gsplus_update_needed;
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static bool bridge_initialized = false;
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void scc_llap_init()
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{
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atbridge_set_diagnostics(g_appletalk_diagnostics);
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bridge_initialized = atbridge_init();
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atbridge_set_net(g_appletalk_network_hint);
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}
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void scc_llap_set_node(byte val)
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{
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atbridge_set_node(val);
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}
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void scc_llap_update()
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{
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if (bridge_initialized)
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{
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atbridge_process();
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// Save the AppleTalk network number. Since the network number does not
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// change very often, this will slightly improve startup time.
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if (g_appletalk_network_hint != atbridge_get_net())
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{
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g_appletalk_network_hint = atbridge_get_net();
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g_config_gsplus_update_needed = 1;
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}
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}
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}
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/** Transfer one packet from the bridge to the SCC **/
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void scc_llap_fill_readbuf(int port, int space_left, double dcycs)
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{
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atbridge_set_diagnostics(g_appletalk_diagnostics);
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byte* data;
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if (!bridge_initialized)
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return;
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data = NULL;
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size_t bytes_read;
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size_t i;
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llap_dequeue_out(dcycs, &bytes_read, &data);
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for(i = 0; i < bytes_read; i++) {
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scc_add_to_readbuf(port, data[i], dcycs);
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}
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free(data);
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// Normally, the bridge updates from the 60 Hz loop, but that alone bottlenecks network throughput.
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scc_llap_update();
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}
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/** Transfer one packet from the SCC to the AppleTalk bridge. **/
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void scc_llap_empty_writebuf(int port, double dcycs)
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{
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atbridge_set_diagnostics(g_appletalk_diagnostics);
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Scc* scc_ptr;
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if (!bridge_initialized)
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return;
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int rdptr;
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int wrptr;
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int len;
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scc_ptr = &(scc_stat[port]);
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// If there's data in the output buffer, send it.
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rdptr = scc_ptr->out_rdptr;
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wrptr = scc_ptr->out_wrptr;
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if(rdptr == wrptr)
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return;
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len = wrptr - rdptr;
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if (len < 0)
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{
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// The data is not contiguous since it wraps around the end of the buffer.
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// But, this should never happen since this function always empties the entire
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// buffer, and the buffer is large enough to hold the maximum packet size.
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halt_printf("SCC LLAP: Unexpected non-contiguous data. Dropping packet.\n");
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}
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else
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{
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// The data is contiguous, so read the data directly from the buffer.
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llap_enqueue_in(dcycs, len, &scc_ptr->out_buf[rdptr]);
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}
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// Remove the sent data from the output buffer. Since the buffer contains
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// one complete packet, always send all of the data.
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scc_ptr->out_rdptr = 0;
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scc_ptr->out_wrptr = 0;
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// Latch EOM to indicate that the SCC has sent the message.
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// The timing will be a bit off from the real hardware since we're not
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// emulating the sending hardware timing and CRC generation.
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scc_ptr->eom = 1;
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// Normally, the bridge updates from the 60 Hz loop, but that alone bottlenecks network throughput.
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scc_llap_update();
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}
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#else
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void scc_llap_init()
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{
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}
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void scc_llap_set_node(byte val)
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{
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}
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void scc_llap_update()
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{
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}
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void scc_llap_fill_readbuf(int port, int space_left, double dcycs)
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{
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}
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void scc_llap_empty_writebuf(int port, double dcycs)
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{
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}
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#endif
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