/* kernel writes to system console -- never sleep! */
void kputchar(char c)
{
while(tty_writeready(TTYDEV - 512) != TTY_READY_NOW);
if (c == '\n')
tty_putc(TTYDEV - 512, '\r');
while(tty_writeready(TTYDEV - 512) != TTY_READY_NOW);
tty_putc(TTYDEV - 512, c);
}
void tty_putc_wait(uint8_t minor, unsigned char c)
{
uint8_t t;
#ifdef CONFIG_DEV_PTY
if (minor >= PTY_OFFSET)
ptty_putc_wait(minor, c);
else
#endif
/* For slower platforms it's not worth the task switching and return
costs versus waiting a bit. A box with tx interrupts and sufficient
performance can buffer or sleep in tty_putc instead.
The driver should return a value from the ttyready_t enum:
1 (TTY_READY_NOW) -- send bytes now
0 (TTY_READY_SOON) -- spinning may be useful
-1 (TTY_READY_LATER) -- blocked, don't spin (eg flow controlled) */
if (!udata.u_ininterrupt) {
while ((t = tty_writeready(minor)) != TTY_READY_NOW)
if (t != TTY_READY_SOON || need_resched()){
irqflags_t irq = di();
tty_sleeping(minor);
psleep(&ttydata[minor]);
irqrestore(irq);
}
}
tty_putc(minor, c);
}
void tty_putc_wait(uint8_t minor, unsigned char c)
{
#ifdef CONFIG_DEV_PTY
if (minor >= PTY_OFFSET)
ptty_putc_wait(minor, c);
else
#endif
if (!udata.u_ininterrupt) {
while (!tty_writeready(minor))
psleep(&ttydata[minor]);
}
tty_putc(minor, c);
}