Hi,
Serial emulation lacks loopback mode (ie a transmitted byte is directly
received in the serial port).
After a reset, serial port registers should go back to default values.
This is done by adding a call to qemu_register_reset().
Attached patch fixes both issues.
Hervé
Index: hw/serial.c
===================================================================
RCS file: /sources/qemu/qemu/hw/serial.c,v
retrieving revision 1.22
diff -u -r1.22 serial.c
--- hw/serial.c 25 Nov 2007 00:55:06 -0000 1.22
+++ hw/serial.c 31 Jan 2008 16:51:19 -0000
@@ -93,6 +93,8 @@
int it_shift;
};
+static void serial_receive_byte(SerialState *s, int ch);
+
static void serial_update_irq(SerialState *s)
{
if ((s->lsr & UART_LSR_DR) && (s->ier & UART_IER_RDI)) {
@@ -161,11 +163,18 @@
s->lsr &= ~UART_LSR_THRE;
serial_update_irq(s);
ch = val;
- qemu_chr_write(s->chr, &ch, 1);
+ if (!(s->mcr & UART_MCR_LOOP)) {
+ /* when not in loopback mode, send the char */
+ qemu_chr_write(s->chr, &ch, 1);
+ }
s->thr_ipending = 1;
s->lsr |= UART_LSR_THRE;
s->lsr |= UART_LSR_TEMT;
serial_update_irq(s);
+ if (s->mcr & UART_MCR_LOOP) {
+ /* in loopback mode, say that we just received a char */
+ serial_receive_byte(s, ch);
+ }
}
break;
case 1:
@@ -223,7 +232,10 @@
ret = s->rbr;
s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
serial_update_irq(s);
- qemu_chr_accept_input(s->chr);
+ if (!(s->mcr & UART_MCR_LOOP)) {
+ /* in loopback mode, don't receive any data */
+ qemu_chr_accept_input(s->chr);
+ }
}
break;
case 1:
@@ -346,6 +358,25 @@
return 0;
}
+static void serial_reset(void *opaque)
+{
+ 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;
+ s->scr = 0;
+
+ s->thr_ipending = 0;
+ s->last_break_enable = 0;
+ qemu_irq_lower(s->irq);
+}
+
/* If fd is zero, it means that the serial device uses the console */
SerialState *serial_init(int base, qemu_irq irq, CharDriverState *chr)
{
@@ -355,9 +386,9 @@
if (!s)
return NULL;
s->irq = irq;
- s->lsr = UART_LSR_TEMT | UART_LSR_THRE;
- s->iir = UART_IIR_NO_INT;
- s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS;
+
+ qemu_register_reset(serial_reset, s);
+ serial_reset(s);
register_savevm("serial", base, 2, serial_save, serial_load, s);
@@ -452,12 +483,12 @@
if (!s)
return NULL;
s->irq = irq;
- s->lsr = UART_LSR_TEMT | UART_LSR_THRE;
- s->iir = UART_IIR_NO_INT;
- s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS;
s->base = base;
s->it_shift = it_shift;
+ qemu_register_reset(serial_reset, s);
+ serial_reset(s);
+
register_savevm("serial", base, 2, serial_save, serial_load, s);
if (ioregister) {