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* [Qemu-devel] [4993] Upgrade emulated UART to 16550A (Stefano Stabellini)
@ 2008-08-11 14:17 Anthony Liguori
  2008-08-12  7:26 ` Brad Campbell
  2008-08-12  7:30 ` Brad Campbell
  0 siblings, 2 replies; 3+ messages in thread
From: Anthony Liguori @ 2008-08-11 14:17 UTC (permalink / raw)
  To: qemu-devel

Revision: 4993
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=4993
Author:   aliguori
Date:     2008-08-11 14:17:04 +0000 (Mon, 11 Aug 2008)

Log Message:
-----------
Upgrade emulated UART to 16550A (Stefano Stabellini)

This patch upgrades the emulated UART to 16550A, the code comes from
xen-unstable. The main improvement was introduced with the following patch and
subsequent email thread:

http://lists.xensource.com/archives/html/xen-devel/2007-12/msg00129.html

The changes compared to previous version are:

- change clock_gettime to qemu_get_clock

- no token bucket anymore;

- fixed a small bug handling IRQs; this was the problem that prevented
kgdb to work over the serial (thanks to Jason Wessel for the help
spotting and reproducing this bug).

- many many style fixes;

- savevm version number increased;

- not including termios.h and sys/ioctl.h anymore, declaring static
constants in qemu-char.h instead;

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Modified Paths:
--------------
    trunk/hw/serial.c
    trunk/qemu-char.h
    trunk/vl.c

Modified: trunk/hw/serial.c
===================================================================
--- trunk/hw/serial.c	2008-08-06 19:50:16 UTC (rev 4992)
+++ trunk/hw/serial.c	2008-08-11 14:17:04 UTC (rev 4993)
@@ -1,7 +1,8 @@
 /*
- * QEMU 16450 UART emulation
+ * QEMU 16550A UART emulation
  *
  * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2008 Citrix Systems, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -43,7 +44,11 @@
 #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 */
+#define UART_IIR_CTI    0x0C    /* Character Timeout Indication */
 
+#define UART_IIR_FENF   0x80    /* Fifo enabled, but not functionning */
+#define UART_IIR_FE     0xC0    /* Fifo enabled */
+
 /*
  * These are the definitions for the Modem Control Register
  */
@@ -73,17 +78,39 @@
 #define UART_LSR_PE	0x04	/* Parity error indicator */
 #define UART_LSR_OE	0x02	/* Overrun error indicator */
 #define UART_LSR_DR	0x01	/* Receiver data ready */
+#define UART_LSR_INT_ANY 0x1E	/* Any of the lsr-interrupt-triggering status bits */
 
-/*
- * Delay TX IRQ after sending as much characters as the given interval would
- * contain on real hardware. This avoids overloading the guest if it processes
- * its output buffer in a loop inside the TX IRQ handler.
- */
-#define THROTTLE_TX_INTERVAL	10 /* ms */
+/* Interrupt trigger levels. The byte-counts are for 16550A - in newer UARTs the byte-count for each ITL is higher. */
 
+#define UART_FCR_ITL_1      0x00 /* 1 byte ITL */
+#define UART_FCR_ITL_2      0x40 /* 4 bytes ITL */
+#define UART_FCR_ITL_3      0x80 /* 8 bytes ITL */
+#define UART_FCR_ITL_4      0xC0 /* 14 bytes ITL */
+
+#define UART_FCR_DMS        0x08    /* DMA Mode Select */
+#define UART_FCR_XFR        0x04    /* XMIT Fifo Reset */
+#define UART_FCR_RFR        0x02    /* RCVR Fifo Reset */
+#define UART_FCR_FE         0x01    /* FIFO Enable */
+
+#define UART_FIFO_LENGTH    16      /* 16550A Fifo Length */
+
+#define XMIT_FIFO           0
+#define RECV_FIFO           1
+#define MAX_XMIT_RETRY      4
+
+struct SerialFIFO {
+    uint8_t data[UART_FIFO_LENGTH];
+    uint8_t count;
+    uint8_t itl;                        /* Interrupt Trigger Level */
+    uint8_t tail;
+    uint8_t head;
+} typedef SerialFIFO;
+
 struct SerialState {
     uint16_t divider;
     uint8_t rbr; /* receive register */
+    uint8_t thr; /* transmit holding register */
+    uint8_t tsr; /* transmit shift register */
     uint8_t ier;
     uint8_t iir; /* read only */
     uint8_t lcr;
@@ -91,6 +118,7 @@
     uint8_t lsr; /* read only */
     uint8_t msr; /* read only */
     uint8_t scr;
+    uint8_t fcr;
     /* NOTE: this hidden state is necessary for tx irq generation as
        it can be reset while reading iir */
     int thr_ipending;
@@ -100,55 +128,106 @@
     target_phys_addr_t base;
     int it_shift;
     int baudbase;
-    QEMUTimer *tx_timer;
-    int tx_burst;
+    int tsr_retry;
+
+    uint64_t last_xmit_ts;              /* Time when the last byte was successfully sent out of the tsr */
+    SerialFIFO recv_fifo;
+    SerialFIFO xmit_fifo;
+
+    struct QEMUTimer *fifo_timeout_timer;
+    int timeout_ipending;                   /* timeout interrupt pending state */
+    struct QEMUTimer *transmit_timer;
+
+
+    uint64_t char_transmit_time;               /* time to transmit a char in ticks*/
+    int poll_msl;
+
+    struct QEMUTimer *modem_status_poll;
 };
 
-static void serial_receive_byte(SerialState *s, int ch);
+static void serial_receive1(void *opaque, const uint8_t *buf, int size);
 
-static void serial_update_irq(SerialState *s)
+static void fifo_clear(SerialState *s, int fifo)
 {
-    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) {
-        qemu_irq_raise(s->irq);
-    } else {
-        qemu_irq_lower(s->irq);
-    }
+    SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
+    memset(f->data, 0, UART_FIFO_LENGTH);
+    f->count = 0;
+    f->head = 0;
+    f->tail = 0;
 }
 
-static void serial_tx_done(void *opaque)
+static int fifo_put(SerialState *s, int fifo, uint8_t chr)
 {
-    SerialState *s = opaque;
+    SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
 
-    if (s->tx_burst < 0) {
-        uint16_t divider;
+    f->data[f->head++] = chr;
 
-        if (s->divider)
-          divider = s->divider;
-        else
-          divider = 1;
+    if (f->head == UART_FIFO_LENGTH)
+        f->head = 0;
+    f->count++;
 
-        /* We assume 10 bits/char, OK for this purpose. */
-        s->tx_burst = THROTTLE_TX_INTERVAL * 1000 /
-            (1000000 * 10 / (s->baudbase / divider));
+    return 1;
+}
+
+static uint8_t fifo_get(SerialState *s, int fifo)
+{
+    SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
+    uint8_t c;
+
+    if(f->count == 0)
+        return 0;
+
+    c = f->data[f->tail++];
+    if (f->tail == UART_FIFO_LENGTH)
+        f->tail = 0;
+    f->count--;
+
+    return c;
+}
+
+static void serial_update_irq(SerialState *s)
+{
+    uint8_t tmp_iir = UART_IIR_NO_INT;
+
+    if (!s->ier) {
+        qemu_irq_lower(s->irq);
+        return;
     }
-    s->thr_ipending = 1;
-    s->lsr |= UART_LSR_THRE;
-    s->lsr |= UART_LSR_TEMT;
-    serial_update_irq(s);
+
+    if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) {
+        tmp_iir = UART_IIR_RLSI;
+    } else if (s->timeout_ipending) {
+        tmp_iir = UART_IIR_CTI;
+    } else if ((s->ier & UART_IER_RDI) && (s->lsr & UART_LSR_DR)) {
+        if (!(s->fcr & UART_FCR_FE)) {
+           tmp_iir = UART_IIR_RDI;
+        } else if (s->recv_fifo.count >= s->recv_fifo.itl) {
+           tmp_iir = UART_IIR_RDI;
+        }
+    } else if ((s->ier & UART_IER_THRI) && s->thr_ipending) {
+        tmp_iir = UART_IIR_THRI;
+    } else if ((s->ier & UART_IER_MSI) && (s->msr & UART_MSR_ANY_DELTA)) {
+        tmp_iir = UART_IIR_MSI;
+    }
+
+    s->iir = tmp_iir | (s->iir & 0xF0);
+
+    if (tmp_iir != UART_IIR_NO_INT) {
+        qemu_irq_raise(s->irq);
+    } else {
+        qemu_irq_lower(s->irq);
+    }
 }
 
 static void serial_update_parameters(SerialState *s)
 {
-    int speed, parity, data_bits, stop_bits;
+    int speed, parity, data_bits, stop_bits, frame_size;
     QEMUSerialSetParams ssp;
 
+    if (s->divider == 0)
+        return;
+
+    frame_size = 1;
     if (s->lcr & 0x08) {
         if (s->lcr & 0x10)
             parity = 'E';
@@ -156,19 +235,21 @@
             parity = 'O';
     } else {
             parity = 'N';
+            frame_size = 0;
     }
     if (s->lcr & 0x04)
         stop_bits = 2;
     else
         stop_bits = 1;
+
     data_bits = (s->lcr & 0x03) + 5;
-    if (s->divider == 0)
-        return;
+    frame_size += data_bits + stop_bits;
     speed = s->baudbase / s->divider;
     ssp.speed = speed;
     ssp.parity = parity;
     ssp.data_bits = data_bits;
     ssp.stop_bits = stop_bits;
+    s->char_transmit_time =  (ticks_per_sec / speed) * frame_size;
     qemu_chr_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
 #if 0
     printf("speed=%d parity=%c data=%d stop=%d\n",
@@ -176,10 +257,91 @@
 #endif
 }
 
+static void serial_update_msl(SerialState *s)
+{
+    uint8_t omsr;
+    int flags;
+
+    qemu_del_timer(s->modem_status_poll);
+
+    if (qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_GET_TIOCM, &flags) == -ENOTSUP) {
+        s->poll_msl = -1;
+        return;
+    }
+
+    omsr = s->msr;
+
+    s->msr = (flags & CHR_TIOCM_CTS) ? s->msr | UART_MSR_CTS : s->msr & ~UART_MSR_CTS;
+    s->msr = (flags & CHR_TIOCM_DSR) ? s->msr | UART_MSR_DSR : s->msr & ~UART_MSR_DSR;
+    s->msr = (flags & CHR_TIOCM_CAR) ? s->msr | UART_MSR_DCD : s->msr & ~UART_MSR_DCD;
+    s->msr = (flags & CHR_TIOCM_RI) ? s->msr | UART_MSR_RI : s->msr & ~UART_MSR_RI;
+
+    if (s->msr != omsr) {
+         /* Set delta bits */
+         s->msr = s->msr | ((s->msr >> 4) ^ (omsr >> 4));
+         /* UART_MSR_TERI only if change was from 1 -> 0 */
+         if ((s->msr & UART_MSR_TERI) && !(omsr & UART_MSR_RI))
+             s->msr &= ~UART_MSR_TERI;
+         serial_update_irq(s);
+    }
+
+    /* The real 16550A apparently has a 250ns response latency to line status changes.
+       We'll be lazy and poll only every 10ms, and only poll it at all if MSI interrupts are turned on */
+
+    if (s->poll_msl)
+        qemu_mod_timer(s->modem_status_poll, qemu_get_clock(vm_clock) + ticks_per_sec / 100);
+}
+
+static void serial_xmit(void *opaque)
+{
+    SerialState *s = opaque;
+    uint64_t new_xmit_ts = qemu_get_clock(vm_clock);
+
+    if (s->tsr_retry <= 0) {
+        if (s->fcr & UART_FCR_FE) {
+            s->tsr = fifo_get(s,XMIT_FIFO);
+            if (!s->xmit_fifo.count)
+                s->lsr |= UART_LSR_THRE;
+        } else {
+            s->tsr = s->thr;
+            s->lsr |= UART_LSR_THRE;
+        }
+    }
+
+    if (s->mcr & UART_MCR_LOOP) {
+        /* in loopback mode, say that we just received a char */
+        serial_receive1(s, &s->tsr, 1);
+    } else if (qemu_chr_write(s->chr, &s->tsr, 1) != 1) {
+        if ((s->tsr_retry > 0) && (s->tsr_retry <= MAX_XMIT_RETRY)) {
+            s->tsr_retry++;
+            qemu_mod_timer(s->transmit_timer,  new_xmit_ts + s->char_transmit_time);
+            return;
+        } else if (s->poll_msl < 0) {
+            /* If we exceed MAX_XMIT_RETRY and the backend is not a real serial port, then
+            drop any further failed writes instantly, until we get one that goes through.
+            This is to prevent guests that log to unconnected pipes or pty's from stalling. */
+            s->tsr_retry = -1;
+        }
+    }
+    else {
+        s->tsr_retry = 0;
+    }
+
+    s->last_xmit_ts = qemu_get_clock(vm_clock);
+    if (!(s->lsr & UART_LSR_THRE))
+        qemu_mod_timer(s->transmit_timer, s->last_xmit_ts + s->char_transmit_time);
+
+    if (s->lsr & UART_LSR_THRE) {
+        s->lsr |= UART_LSR_TEMT;
+        s->thr_ipending = 1;
+        serial_update_irq(s);
+    }
+}
+
+
 static void serial_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 {
     SerialState *s = opaque;
-    unsigned char ch;
 
     addr &= 7;
 #ifdef DEBUG_SERIAL
@@ -192,25 +354,19 @@
             s->divider = (s->divider & 0xff00) | val;
             serial_update_parameters(s);
         } else {
+            s->thr = (uint8_t) val;
+            if(s->fcr & UART_FCR_FE) {
+                  fifo_put(s, XMIT_FIFO, s->thr);
             s->thr_ipending = 0;
+                  s->lsr &= ~UART_LSR_TEMT;
             s->lsr &= ~UART_LSR_THRE;
             serial_update_irq(s);
-            ch = val;
-            if (!(s->mcr & UART_MCR_LOOP)) {
-                /* when not in loopback mode, send the char */
-                qemu_chr_write(s->chr, &ch, 1);
             } else {
-                /* in loopback mode, say that we just received a char */
-                serial_receive_byte(s, ch);
+                  s->thr_ipending = 0;
+                  s->lsr &= ~UART_LSR_THRE;
+                  serial_update_irq(s);
             }
-            if (s->tx_burst > 0) {
-                s->tx_burst--;
-                serial_tx_done(s);
-            } else if (s->tx_burst == 0) {
-                s->tx_burst--;
-                qemu_mod_timer(s->tx_timer, qemu_get_clock(vm_clock) +
-                               ticks_per_sec * THROTTLE_TX_INTERVAL / 1000);
-            }
+            serial_xmit(s);
         }
         break;
     case 1:
@@ -219,13 +375,68 @@
             serial_update_parameters(s);
         } else {
             s->ier = val & 0x0f;
+            /* If the backend device is a real serial port, turn polling of the modem
+               status lines on physical port on or off depending on UART_IER_MSI state */
+            if (s->poll_msl >= 0) {
+                if (s->ier & UART_IER_MSI) {
+                     s->poll_msl = 1;
+                     serial_update_msl(s);
+                } else {
+                     qemu_del_timer(s->modem_status_poll);
+                     s->poll_msl = 0;
+                }
+            }
             if (s->lsr & UART_LSR_THRE) {
                 s->thr_ipending = 1;
+                serial_update_irq(s);
             }
-            serial_update_irq(s);
         }
         break;
     case 2:
+        val = val & 0xFF;
+
+        if (s->fcr == val)
+            break;
+
+        /* Did the enable/disable flag change? If so, make sure FIFOs get flushed */
+        if ((val ^ s->fcr) & UART_FCR_FE)
+            val |= UART_FCR_XFR | UART_FCR_RFR;
+
+        /* FIFO clear */
+
+        if (val & UART_FCR_RFR) {
+            qemu_del_timer(s->fifo_timeout_timer);
+            s->timeout_ipending=0;
+            fifo_clear(s,RECV_FIFO);
+        }
+
+        if (val & UART_FCR_XFR) {
+            fifo_clear(s,XMIT_FIFO);
+        }
+
+        if (val & UART_FCR_FE) {
+            s->iir |= UART_IIR_FE;
+            /* Set RECV_FIFO trigger Level */
+            switch (val & 0xC0) {
+            case UART_FCR_ITL_1:
+                s->recv_fifo.itl = 1;
+                break;
+            case UART_FCR_ITL_2:
+                s->recv_fifo.itl = 4;
+                break;
+            case UART_FCR_ITL_3:
+                s->recv_fifo.itl = 8;
+                break;
+            case UART_FCR_ITL_4:
+                s->recv_fifo.itl = 14;
+                break;
+            }
+        } else
+            s->iir &= ~UART_IIR_FE;
+
+        /* Set fcr - or at least the bits in it that are supposed to "stick" */
+        s->fcr = val & 0xC9;
+        serial_update_irq(s);
         break;
     case 3:
         {
@@ -241,7 +452,30 @@
         }
         break;
     case 4:
-        s->mcr = val & 0x1f;
+        {
+            int flags;
+            int old_mcr = s->mcr;
+            s->mcr = val & 0x1f;
+            if (val & UART_MCR_LOOP)
+                break;
+
+            if (s->poll_msl >= 0 && old_mcr != s->mcr) {
+
+                qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_GET_TIOCM, &flags);
+
+                flags &= ~(CHR_TIOCM_RTS | CHR_TIOCM_DTR);
+
+                if (val & UART_MCR_RTS)
+                    flags |= CHR_TIOCM_RTS;
+                if (val & UART_MCR_DTR)
+                    flags |= CHR_TIOCM_DTR;
+
+                qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_SET_TIOCM, &flags);
+                /* Update the modem status after a one-character-send wait-time, since there may be a response
+                   from the device/computer at the other end of the serial line */
+                qemu_mod_timer(s->modem_status_poll, qemu_get_clock(vm_clock) + s->char_transmit_time);
+            }
+        }
         break;
     case 5:
         break;
@@ -265,8 +499,17 @@
         if (s->lcr & UART_LCR_DLAB) {
             ret = s->divider & 0xff;
         } else {
-            ret = s->rbr;
-            s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+            if(s->fcr & UART_FCR_FE) {
+                ret = fifo_get(s,RECV_FIFO);
+                if (s->recv_fifo.count == 0)
+                    s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+                else
+                    qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock (vm_clock) + s->char_transmit_time * 4);
+                s->timeout_ipending = 0;
+            } else {
+                ret = s->rbr;
+                s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
+            }
             serial_update_irq(s);
             if (!(s->mcr & UART_MCR_LOOP)) {
                 /* in loopback mode, don't receive any data */
@@ -283,8 +526,6 @@
         break;
     case 2:
         ret = s->iir;
-        /* reset THR pending bit */
-        if ((ret & 0x7) == UART_IIR_THRI)
             s->thr_ipending = 0;
         serial_update_irq(s);
         break;
@@ -296,6 +537,11 @@
         break;
     case 5:
         ret = s->lsr;
+        /* Clear break interrupt */
+        if (s->lsr & UART_LSR_BI) {
+            s->lsr &= ~UART_LSR_BI;
+            serial_update_irq(s);
+        }
         break;
     case 6:
         if (s->mcr & UART_MCR_LOOP) {
@@ -305,7 +551,14 @@
             ret |= (s->mcr & 0x02) << 3;
             ret |= (s->mcr & 0x01) << 5;
         } else {
+            if (s->poll_msl >= 0)
+                serial_update_msl(s);
             ret = s->msr;
+            /* Clear delta bits & msr int after read, if they were set */
+            if (s->msr & UART_MSR_ANY_DELTA) {
+                s->msr &= 0xF0;
+                serial_update_irq(s);
+            }
         }
         break;
     case 7:
@@ -320,16 +573,19 @@
 
 static int serial_can_receive(SerialState *s)
 {
+    if(s->fcr & UART_FCR_FE) {
+        if(s->recv_fifo.count < UART_FIFO_LENGTH)
+        /* Advertise (fifo.itl - fifo.count) bytes when count < ITL, and 1 if above. If UART_FIFO_LENGTH - fifo.count is
+        advertised the effect will be to almost always fill the fifo completely before the guest has a chance to respond,
+        effectively overriding the ITL that the guest has set. */
+             return (s->recv_fifo.count <= s->recv_fifo.itl) ? s->recv_fifo.itl - s->recv_fifo.count : 1;
+        else
+             return 0;
+    } else {
     return !(s->lsr & UART_LSR_DR);
+    }
 }
 
-static void serial_receive_byte(SerialState *s, int ch)
-{
-    s->rbr = ch;
-    s->lsr |= UART_LSR_DR;
-    serial_update_irq(s);
-}
-
 static void serial_receive_break(SerialState *s)
 {
     s->rbr = 0;
@@ -337,6 +593,15 @@
     serial_update_irq(s);
 }
 
+/* There's data in recv_fifo and s->rbr has not been read for 4 char transmit times */
+static void fifo_timeout_int (void *opaque) {
+    SerialState *s = opaque;
+    if (s->recv_fifo.count) {
+        s->timeout_ipending = 1;
+        serial_update_irq(s);
+    }
+}
+
 static int serial_can_receive1(void *opaque)
 {
     SerialState *s = opaque;
@@ -346,12 +611,27 @@
 static void serial_receive1(void *opaque, const uint8_t *buf, int size)
 {
     SerialState *s = opaque;
-    serial_receive_byte(s, buf[0]);
+    if(s->fcr & UART_FCR_FE) {
+        int i;
+        for (i = 0; i < size; i++) {
+            fifo_put(s, RECV_FIFO, buf[i]);
+        }
+        s->lsr |= UART_LSR_DR;
+        /* call the timeout receive callback in 4 char transmit time */
+        qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock (vm_clock) + s->char_transmit_time * 4);
+    } else {
+        s->rbr = buf[0];
+        s->lsr |= UART_LSR_DR;
+    }
+    serial_update_irq(s);
 }
 
 static void serial_event(void *opaque, int event)
 {
     SerialState *s = opaque;
+#ifdef DEBUG_SERIAL
+    printf("serial: event %x\n", event);
+#endif
     if (event == CHR_EVENT_BREAK)
         serial_receive_break(s);
 }
@@ -369,13 +649,15 @@
     qemu_put_8s(f,&s->lsr);
     qemu_put_8s(f,&s->msr);
     qemu_put_8s(f,&s->scr);
+    qemu_put_8s(f,&s->fcr);
 }
 
 static int serial_load(QEMUFile *f, void *opaque, int version_id)
 {
     SerialState *s = opaque;
+    uint8_t fcr = 0;
 
-    if(version_id > 2)
+    if(version_id > 3)
         return -EINVAL;
 
     if (version_id >= 2)
@@ -391,6 +673,11 @@
     qemu_get_8s(f,&s->msr);
     qemu_get_8s(f,&s->scr);
 
+    if (version_id >= 3)
+        qemu_get_8s(f,&fcr);
+
+    /* Initialize fcr via setter to perform essential side-effects */
+    serial_ioport_write(s, 0x02, fcr);
     return 0;
 }
 
@@ -398,21 +685,47 @@
 {
     SerialState *s = opaque;
 
-    s->divider = 0;
     s->rbr = 0;
     s->ier = 0;
     s->iir = UART_IIR_NO_INT;
     s->lcr = 0;
-    s->mcr = 0;
     s->lsr = UART_LSR_TEMT | UART_LSR_THRE;
     s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS;
+    /* Default to 9600 baud, no parity, one stop bit */
+    s->divider = 0x0C;
+    s->mcr = UART_MCR_OUT2;
     s->scr = 0;
+    s->tsr_retry = 0;
+    s->char_transmit_time = (ticks_per_sec / 9600) * 9;
+    s->poll_msl = 0;
 
+    fifo_clear(s,RECV_FIFO);
+    fifo_clear(s,XMIT_FIFO);
+
+    s->last_xmit_ts = qemu_get_clock(vm_clock);
+
     s->thr_ipending = 0;
     s->last_break_enable = 0;
     qemu_irq_lower(s->irq);
 }
 
+static void serial_init_core(SerialState *s, qemu_irq irq, int baudbase,
+			     CharDriverState *chr)
+{
+    s->irq = irq;
+    s->baudbase = baudbase;
+    s->chr = chr;
+
+    s->modem_status_poll = qemu_new_timer(vm_clock, (QEMUTimerCB *) serial_update_msl, s);
+
+    s->fifo_timeout_timer = qemu_new_timer(vm_clock, (QEMUTimerCB *) fifo_timeout_int, s);
+    s->transmit_timer = qemu_new_timer(vm_clock, (QEMUTimerCB *) serial_xmit, s);
+
+    qemu_register_reset(serial_reset, s);
+    serial_reset(s);
+
+}
+
 /* If fd is zero, it means that the serial device uses the console */
 SerialState *serial_init(int base, qemu_irq irq, int baudbase,
                          CharDriverState *chr)
@@ -422,21 +735,13 @@
     s = qemu_mallocz(sizeof(SerialState));
     if (!s)
         return NULL;
-    s->irq = irq;
-    s->baudbase = baudbase;
 
-    s->tx_timer = qemu_new_timer(vm_clock, serial_tx_done, s);
-    if (!s->tx_timer)
-        return NULL;
+    serial_init_core(s, irq, baudbase, chr);
 
-    qemu_register_reset(serial_reset, s);
-    serial_reset(s);
+    register_savevm("serial", base, 3, serial_save, serial_load, s);
 
-    register_savevm("serial", base, 2, serial_save, serial_load, s);
-
     register_ioport_write(base, 8, 1, serial_ioport_write, s);
     register_ioport_read(base, 8, 1, serial_ioport_read, s);
-    s->chr = chr;
     qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1,
                           serial_event, s);
     return s;
@@ -524,27 +829,20 @@
     s = qemu_mallocz(sizeof(SerialState));
     if (!s)
         return NULL;
-    s->irq = irq;
+
     s->base = base;
     s->it_shift = it_shift;
-    s->baudbase= baudbase;
 
-    s->tx_timer = qemu_new_timer(vm_clock, serial_tx_done, s);
-    if (!s->tx_timer)
-        return NULL;
+    serial_init_core(s, irq, baudbase, chr);
+    register_savevm("serial", base, 3, serial_save, serial_load, s);
 
-    qemu_register_reset(serial_reset, s);
-    serial_reset(s);
-
-    register_savevm("serial", base, 2, serial_save, serial_load, s);
-
     if (ioregister) {
         s_io_memory = cpu_register_io_memory(0, serial_mm_read,
                                              serial_mm_write, s);
         cpu_register_physical_memory(base, 8 << it_shift, s_io_memory);
     }
-    s->chr = chr;
     qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1,
                           serial_event, s);
+    serial_update_msl(s);
     return s;
 }

Modified: trunk/qemu-char.h
===================================================================
--- trunk/qemu-char.h	2008-08-06 19:50:16 UTC (rev 4992)
+++ trunk/qemu-char.h	2008-08-11 14:17:04 UTC (rev 4993)
@@ -28,6 +28,16 @@
 #define CHR_IOCTL_PP_EPP_WRITE_ADDR  10
 #define CHR_IOCTL_PP_EPP_WRITE       11
 
+#define CHR_IOCTL_SERIAL_SET_TIOCM   12
+#define CHR_IOCTL_SERIAL_GET_TIOCM   13
+
+#define CHR_TIOCM_CTS	0x020
+#define CHR_TIOCM_CAR	0x040
+#define CHR_TIOCM_DSR	0x100
+#define CHR_TIOCM_RI	0x080
+#define CHR_TIOCM_DTR	0x002
+#define CHR_TIOCM_RTS	0x004
+
 typedef void IOEventHandler(void *opaque, int event);
 
 struct CharDriverState {

Modified: trunk/vl.c
===================================================================
--- trunk/vl.c	2008-08-06 19:50:16 UTC (rev 4992)
+++ trunk/vl.c	2008-08-11 14:17:04 UTC (rev 4993)
@@ -2721,6 +2721,37 @@
                 tcsendbreak(s->fd_in, 1);
         }
         break;
+    case CHR_IOCTL_SERIAL_GET_TIOCM:
+        {
+            int sarg = 0;
+            int *targ = (int *)arg;
+            ioctl(s->fd_in, TIOCMGET, &sarg);
+            *targ = 0;
+            if (sarg | TIOCM_CTS)
+                *targ |= CHR_TIOCM_CTS;
+            if (sarg | TIOCM_CAR)
+                *targ |= CHR_TIOCM_CAR;
+            if (sarg | TIOCM_DSR)
+                *targ |= CHR_TIOCM_DSR;
+            if (sarg | TIOCM_RI)
+                *targ |= CHR_TIOCM_RI;
+            if (sarg | TIOCM_DTR)
+                *targ |= CHR_TIOCM_DTR;
+            if (sarg | TIOCM_RTS)
+                *targ |= CHR_TIOCM_RTS;
+        }
+        break;
+    case CHR_IOCTL_SERIAL_SET_TIOCM:
+        {
+            int sarg = *(int *)arg;
+            int targ = 0;
+            if (sarg | CHR_TIOCM_DTR)
+                targ |= TIOCM_DTR;
+            if (sarg | CHR_TIOCM_RTS)
+                targ |= TIOCM_RTS;
+            ioctl(s->fd_in, TIOCMSET, &targ);
+        }
+        break;
     default:
         return -ENOTSUP;
     }

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Qemu-devel] [4993] Upgrade emulated UART to 16550A (Stefano Stabellini)
  2008-08-11 14:17 [Qemu-devel] [4993] Upgrade emulated UART to 16550A (Stefano Stabellini) Anthony Liguori
@ 2008-08-12  7:26 ` Brad Campbell
  2008-08-12  7:30 ` Brad Campbell
  1 sibling, 0 replies; 3+ messages in thread
From: Brad Campbell @ 2008-08-12  7:26 UTC (permalink / raw)
  To: qemu-devel

Anthony Liguori wrote:
> Revision: 4993
>           http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=4993
> Author:   aliguori
> Date:     2008-08-11 14:17:04 +0000 (Mon, 11 Aug 2008)
> 
> Log Message:
> -----------
> Upgrade emulated UART to 16550A (Stefano Stabellini)
> 
> This patch upgrades the emulated UART to 16550A, the code comes from
> xen-unstable. The main improvement was introduced with the following patch and
> subsequent email thread:
> 

This patch breaks installing Windows XP. See my mail earlier this morning.
SVN Rev 4992 works fine, 4993 hangs at "Setup is starting Windows"

Brad
-- 
Dolphins are so intelligent that within a few weeks they can
train Americans to stand at the edge of the pool and throw them
fish.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Qemu-devel] [4993] Upgrade emulated UART to 16550A (Stefano Stabellini)
  2008-08-11 14:17 [Qemu-devel] [4993] Upgrade emulated UART to 16550A (Stefano Stabellini) Anthony Liguori
  2008-08-12  7:26 ` Brad Campbell
@ 2008-08-12  7:30 ` Brad Campbell
  1 sibling, 0 replies; 3+ messages in thread
From: Brad Campbell @ 2008-08-12  7:30 UTC (permalink / raw)
  To: qemu-devel

Anthony Liguori wrote:
> Revision: 4993
>           http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=4993
> Author:   aliguori
> Date:     2008-08-11 14:17:04 +0000 (Mon, 11 Aug 2008)
> 
> Log Message:
> -----------
> Upgrade emulated UART to 16550A (Stefano Stabellini)
> 
> This patch upgrades the emulated UART to 16550A, the code comes from
> xen-unstable. The main improvement was introduced with the following patch and
> subsequent email thread:
> 

I guess if I'd had half a brain I'd have posted some actual useful information, sorry my bad.

brad@bklaptop2:/tracks/src/src/qemu$ ./configure
WARNING: "gcc" looks like gcc 4.x
Looking for gcc 3.x
Found "gcc-3.4"
Install prefix    /usr/local
BIOS directory    /usr/local/share/qemu
binary directory  /usr/local/bin
Manual directory  /usr/local/share/man
ELF interp prefix /usr/gnemul/qemu-%M
Source path       /tracks/src/src/qemu
C compiler        gcc-3.4
Host C compiler   gcc
ARCH_CFLAGS       -m32
make              make
install           install
host CPU          i386
host big endian   no
target list       i386-softmmu x86_64-softmmu arm-softmmu cris-softmmu m68k-softmmu mips-softmmu 
mipsel-softmmu mips64-softmmu mips64el-softmmu ppc-softmmu ppcemb-softmmu ppc64-softmmu sh4-softmmu 
sh4eb-softmmu sparc-softmmu i386-linux-user x86_64-linux-user alpha-linux-user arm-linux-user 
armeb-linux-user cris-linux-user m68k-linux-user mips-linux-user mipsel-linux-user ppc-linux-user 
ppc64-linux-user ppc64abi32-linux-user sh4-linux-user sh4eb-linux-user sparc-linux-user 
sparc64-linux-user sparc32plus-linux-user
gprof enabled     no
profiler          no
static build      no
-Werror enabled   no
SDL support       yes
SDL static link   yes
curses support    yes
mingw32 support   no
Audio drivers     oss
Extra audio cards
Mixer emulation   no
VNC TLS support   no
kqemu support     yes
brlapi support    no
Documentation     no
NPTL support      yes
vde support       no

brad@bklaptop2:/tracks/src/src/qemu$ cat /proc/cpuinfo
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 13
model name	: Intel(R) Pentium(R) M processor 1.20GHz
stepping	: 8
cpu MHz		: 1200.000
cache size	: 2048 KB
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
fpu		: yes
fpu_exception	: yes
cpuid level	: 2
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr 
sse sse2 ss tm pbe nx bts est tm2
bogomips	: 2396.25
clflush size	: 64
power management:


-- 
Dolphins are so intelligent that within a few weeks they can
train Americans to stand at the edge of the pool and throw them
fish.

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2008-08-12  7:30 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-08-11 14:17 [Qemu-devel] [4993] Upgrade emulated UART to 16550A (Stefano Stabellini) Anthony Liguori
2008-08-12  7:26 ` Brad Campbell
2008-08-12  7:30 ` Brad Campbell

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