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-rw-r--r--hw/serial.c281
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diff --git a/hw/serial.c b/hw/serial.c
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+/*
+ * QEMU 16450 UART emulation
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/time.h>
+#include <malloc.h>
+#include <termios.h>
+#include <sys/poll.h>
+#include <errno.h>
+#include <sys/wait.h>
+#include <netinet/in.h>
+
+#include "cpu.h"
+#include "vl.h"
+
+//#define DEBUG_SERIAL
+
+#define UART_LCR_DLAB 0x80 /* Divisor latch access bit */
+
+#define UART_IER_MSI 0x08 /* Enable Modem status interrupt */
+#define UART_IER_RLSI 0x04 /* Enable receiver line status interrupt */
+#define UART_IER_THRI 0x02 /* Enable Transmitter holding register int. */
+#define UART_IER_RDI 0x01 /* Enable receiver data interrupt */
+
+#define UART_IIR_NO_INT 0x01 /* No interrupts pending */
+#define UART_IIR_ID 0x06 /* Mask for the interrupt ID */
+
+#define UART_IIR_MSI 0x00 /* Modem status interrupt */
+#define UART_IIR_THRI 0x02 /* Transmitter holding register empty */
+#define UART_IIR_RDI 0x04 /* Receiver data interrupt */
+#define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */
+
+/*
+ * These are the definitions for the Modem Control Register
+ */
+#define UART_MCR_LOOP 0x10 /* Enable loopback test mode */
+#define UART_MCR_OUT2 0x08 /* Out2 complement */
+#define UART_MCR_OUT1 0x04 /* Out1 complement */
+#define UART_MCR_RTS 0x02 /* RTS complement */
+#define UART_MCR_DTR 0x01 /* DTR complement */
+
+/*
+ * These are the definitions for the Modem Status Register
+ */
+#define UART_MSR_DCD 0x80 /* Data Carrier Detect */
+#define UART_MSR_RI 0x40 /* Ring Indicator */
+#define UART_MSR_DSR 0x20 /* Data Set Ready */
+#define UART_MSR_CTS 0x10 /* Clear to Send */
+#define UART_MSR_DDCD 0x08 /* Delta DCD */
+#define UART_MSR_TERI 0x04 /* Trailing edge ring indicator */
+#define UART_MSR_DDSR 0x02 /* Delta DSR */
+#define UART_MSR_DCTS 0x01 /* Delta CTS */
+#define UART_MSR_ANY_DELTA 0x0F /* Any of the delta bits! */
+
+#define UART_LSR_TEMT 0x40 /* Transmitter empty */
+#define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
+#define UART_LSR_BI 0x10 /* Break interrupt indicator */
+#define UART_LSR_FE 0x08 /* Frame error indicator */
+#define UART_LSR_PE 0x04 /* Parity error indicator */
+#define UART_LSR_OE 0x02 /* Overrun error indicator */
+#define UART_LSR_DR 0x01 /* Receiver data ready */
+
+typedef struct SerialState {
+ uint8_t divider;
+ uint8_t rbr; /* receive register */
+ uint8_t ier;
+ uint8_t iir; /* read only */
+ uint8_t lcr;
+ uint8_t mcr;
+ uint8_t lsr; /* read only */
+ uint8_t msr;
+ uint8_t scr;
+ /* NOTE: this hidden state is necessary for tx irq generation as
+ it can be reset while reading iir */
+ int thr_ipending;
+ int irq;
+} SerialState;
+
+SerialState serial_ports[1];
+
+void serial_update_irq(void)
+{
+ SerialState *s = &serial_ports[0];
+
+ if ((s->lsr & UART_LSR_DR) && (s->ier & UART_IER_RDI)) {
+ s->iir = UART_IIR_RDI;
+ } else if (s->thr_ipending && (s->ier & UART_IER_THRI)) {
+ s->iir = UART_IIR_THRI;
+ } else {
+ s->iir = UART_IIR_NO_INT;
+ }
+ if (s->iir != UART_IIR_NO_INT) {
+ pic_set_irq(s->irq, 1);
+ } else {
+ pic_set_irq(s->irq, 0);
+ }
+}
+
+void serial_ioport_write(CPUState *env, uint32_t addr, uint32_t val)
+{
+ SerialState *s = &serial_ports[0];
+ unsigned char ch;
+ int ret;
+
+ addr &= 7;
+#ifdef DEBUG_SERIAL
+ printf("serial: write addr=0x%02x val=0x%02x\n", addr, val);
+#endif
+ switch(addr) {
+ default:
+ case 0:
+ if (s->lcr & UART_LCR_DLAB) {
+ s->divider = (s->divider & 0xff00) | val;
+ } else {
+ s->thr_ipending = 0;
+ s->lsr &= ~UART_LSR_THRE;
+ serial_update_irq();
+
+ ch = val;
+ do {
+ ret = write(1, &ch, 1);
+ } while (ret != 1);
+ s->thr_ipending = 1;
+ s->lsr |= UART_LSR_THRE;
+ s->lsr |= UART_LSR_TEMT;
+ serial_update_irq();
+ }
+ break;
+ case 1:
+ if (s->lcr & UART_LCR_DLAB) {
+ s->divider = (s->divider & 0x00ff) | (val << 8);
+ } else {
+ s->ier = val;
+ serial_update_irq();
+ }
+ break;
+ case 2:
+ break;
+ case 3:
+ s->lcr = val;
+ break;
+ case 4:
+ s->mcr = val;
+ break;
+ case 5:
+ break;
+ case 6:
+ s->msr = val;
+ break;
+ case 7:
+ s->scr = val;
+ break;
+ }
+}
+
+uint32_t serial_ioport_read(CPUState *env, uint32_t addr)
+{
+ SerialState *s = &serial_ports[0];
+ uint32_t ret;
+
+ addr &= 7;
+ switch(addr) {
+ default:
+ case 0:
+ if (s->lcr & UART_LCR_DLAB) {
+ ret = s->divider & 0xff;
+ } else {
+ ret = s->rbr;
+ s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+ serial_update_irq();
+ }
+ break;
+ case 1:
+ if (s->lcr & UART_LCR_DLAB) {
+ ret = (s->divider >> 8) & 0xff;
+ } else {
+ ret = s->ier;
+ }
+ break;
+ case 2:
+ ret = s->iir;
+ /* reset THR pending bit */
+ if ((ret & 0x7) == UART_IIR_THRI)
+ s->thr_ipending = 0;
+ serial_update_irq();
+ break;
+ case 3:
+ ret = s->lcr;
+ break;
+ case 4:
+ ret = s->mcr;
+ break;
+ case 5:
+ ret = s->lsr;
+ break;
+ case 6:
+ if (s->mcr & UART_MCR_LOOP) {
+ /* in loopback, the modem output pins are connected to the
+ inputs */
+ ret = (s->mcr & 0x0c) << 4;
+ ret |= (s->mcr & 0x02) << 3;
+ ret |= (s->mcr & 0x01) << 5;
+ } else {
+ ret = s->msr;
+ }
+ break;
+ case 7:
+ ret = s->scr;
+ break;
+ }
+#ifdef DEBUG_SERIAL
+ printf("serial: read addr=0x%02x val=0x%02x\n", addr, ret);
+#endif
+ return ret;
+}
+
+int serial_can_receive(void)
+{
+ SerialState *s = &serial_ports[0];
+ return !(s->lsr & UART_LSR_DR);
+}
+
+void serial_receive_byte(int ch)
+{
+ SerialState *s = &serial_ports[0];
+
+ s->rbr = ch;
+ s->lsr |= UART_LSR_DR;
+ serial_update_irq();
+}
+
+void serial_receive_break(void)
+{
+ SerialState *s = &serial_ports[0];
+
+ s->rbr = 0;
+ s->lsr |= UART_LSR_BI | UART_LSR_DR;
+ serial_update_irq();
+}
+
+void serial_init(int base, int irq)
+{
+ SerialState *s = &serial_ports[0];
+
+ s->irq = irq;
+ s->lsr = UART_LSR_TEMT | UART_LSR_THRE;
+ s->iir = UART_IIR_NO_INT;
+
+ register_ioport_write(base, 8, serial_ioport_write, 1);
+ register_ioport_read(base, 8, serial_ioport_read, 1);
+}
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