提交 b2a5160c 编写于 作者: B balrog

Add serial loopback mode (patch from Hervé Poussineau).


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3973 c046a42c-6fe2-441c-8c8c-71466251a162
上级 e41c0f26
......@@ -93,6 +93,8 @@ struct SerialState {
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 @@ static void serial_ioport_write(void *opaque, uint32_t addr, uint32_t val)
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 @@ static uint32_t serial_ioport_read(void *opaque, uint32_t addr)
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 @@ static int serial_load(QEMUFile *f, void *opaque, int version_id)
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 @@ SerialState *serial_init(int base, qemu_irq irq, CharDriverState *chr)
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 @@ SerialState *serial_mm_init (target_phys_addr_t base, int it_shift,
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) {
......
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