C++ cngetc函数代码示例

/*
 * void cpu_reboot(int howto, char *bootstr)
 *
 * Reboots the system
 *
 * Deal with any syncing, unmounting, dumping and shutdown hooks,
 * then reset the CPU.
 */
void
cpu_reboot(int howto, char *bootstr)
{

	/*
	 * If we are still cold then hit the air brakes
	 * and crash to earth fast
	 */
	if (cold) {
		doshutdownhooks();
		printf("The operating system has halted.\n");
		printf("Please press any key to reboot.\n\n");
		cngetc();
		printf("rebooting...\n");
		goto reset;
	}

	/* Disable console buffering */

	/*
	 * If RB_NOSYNC was not specified sync the discs.
	 * Note: Unless cold is set to 1 here, syslogd will die during the
	 * unmount.  It looks like syslogd is getting woken up only to find
	 * that it cannot page part of the binary in as the filesystem has
	 * been unmounted.
	 */
	if (!(howto & RB_NOSYNC))
		bootsync();

	/* Say NO to interrupts */
	splhigh();

	/* Do a dump if requested. */
	if ((howto & (RB_DUMP | RB_HALT)) == RB_DUMP)
		dumpsys();
	
	/* Run any shutdown hooks */
	doshutdownhooks();

	/* Make sure IRQ's are disabled */
	IRQdisable;

	if (howto & RB_HALT) {
		brh_7seg('8');
		printf("The operating system has halted.\n");
		printf("Please press any key to reboot.\n\n");
		cngetc();
	}

	printf("rebooting...\n\r");
 reset:
	cpu_reset();
}

/*
 * Simple pager
 */
int
db_more(int *nl)
{
	++*nl;
	if (*nl == 20) {
		int c;

		db_printf("--More--");
		c = cngetc();
		db_printf("\r");
		/*
		 * A whole screenfull or just one line?
		 */
		switch (c) {
		case '\n':		/* just one line */
			*nl = 19;
			break;
		case ' ':
			*nl = 0;	/* another screenfull */
			break;
		default:		/* exit */
			db_printf("\n");
			return(-1);
		}
	}
	return(0);
}

void
cpu_reboot(int howto, char *bootstr)
{
	extern void exit(int);
	extern void abort(void);

	splhigh();

	if ((howto & RB_POWERDOWN) == RB_POWERDOWN)
		exit(0);

	if (howto & RB_HALT) {
		printf("\n");
		printf("The operating system has halted.\n");
		printf("Please press any key to reboot.\n\n");
		cnpollc(1);
		cngetc();
		cnpollc(0);
	}

	printf("rebooting...\n");

	/*
	 * XXXJDM If we've panic'd, make sure we dump a core
	 */
	abort();

	/* NOTREACHED */
}

static void
db_more()
{
	register  char *p;
	boolean_t quit_output = FALSE;

	for (p = "--db_more--"; *p; p++)
	    cnputc(*p);
	switch(cngetc()) {
	case ' ':
	    db_output_line = 0;
	    break;
	case 'q':
	case CTRL('c'):
	    db_output_line = 0;
	    quit_output = TRUE;
	    break;
	default:
	    db_output_line--;
	    break;
	}
	p = "\b\b\b\b\b\b\b\b\b\b\b           \b\b\b\b\b\b\b\b\b\b\b";
	while (*p)
	    cnputc(*p++);
	if (quit_output) {
	    db_error(0);
	    /* NOTREACHED */
	}
}

static void
db_more(void)
{
	char *p;
	int quit_output = 0;

	for (p = "--db_more--"; *p; p++)
	    cnputc(*p);
	switch(cngetc()) {
	case ' ':
	    db_output_line = 0;
	    break;
	case 'q':
	case CTRL('c'):
	    db_output_line = 0;
	    quit_output = 1;
	    break;
	default:
	    db_output_line--;
	    break;
	}
	p = "\b\b\b\b\b\b\b\b\b\b\b           \b\b\b\b\b\b\b\b\b\b\b";
	while (*p)
	    cnputc(*p++);
	if (quit_output) {
	    db_error(0);
	    /* NOTREACHED */
	}
}

/*
 * Check to see if the system paniced, pause and then reboot
 * according to the specified delay.
 */
static void
shutdown_panic(void *junk, int howto)
{
	int loop;

	if (howto & RB_DUMP) {
		if (PANIC_REBOOT_WAIT_TIME != 0) {
			if (PANIC_REBOOT_WAIT_TIME != -1) {
				kprintf("Automatic reboot in %d seconds - "
				       "press a key on the console to abort\n",
					PANIC_REBOOT_WAIT_TIME);
				for (loop = PANIC_REBOOT_WAIT_TIME * 10;
				     loop > 0; --loop) {
					DELAY(1000 * 100); /* 1/10th second */
					/* Did user type a key? */
					if (cncheckc() != -1)
						break;
				}
				if (!loop)
					return;
			}
		} else { /* zero time specified - reboot NOW */
			return;
		}
		kprintf("--> Press a key on the console to reboot,\n");
		kprintf("--> or switch off the system now.\n");
		cngetc();
	}
}

void
boot(int howto)
{

	if (cold) {
		if ((howto & RB_USERREQ) == 0)
			howto |= RB_HALT;
		goto haltsys;
	}

	boothowto = howto;
	if ((howto & RB_NOSYNC) == 0) {
		vfs_shutdown();
		/*
		 * If we've been adjusting the clock, the todr
		 * will be out of synch; adjust it now.
		 */
		if ((howto & RB_TIMEBAD) == 0)
			resettodr();
		else
			printf("WARNING: not updating battery clock\n");
	}

	uvm_shutdown();
	splhigh();		/* Disable interrupts. */

	/* Do a dump if requested. */
	if (howto & RB_DUMP)
		dumpsys();

haltsys:
	doshutdownhooks();

	if ((howto & RB_POWERDOWN) == RB_POWERDOWN) {
		_reg_write_1(LANDISK_PWRMNG, PWRMNG_POWEROFF);
		delay(1 * 1000 * 1000);
		printf("POWEROFF FAILED!\n");
		howto |= RB_HALT;
	}

	if (howto & RB_HALT) {
		printf("\n");
		printf("The operating system has halted.\n");
		printf("Please press any key to reboot.\n\n");
		cnpollc(1);
		cngetc();
		cnpollc(0);
	}

	printf("rebooting...\n");
	machine_reset();

	/*NOTREACHED*/
	for (;;) {
		continue;
	}
}

void
cpu_reboot(int howto, char *bootstr)
{

	/* Take a snapshot before clobbering any registers. */
	savectx(curpcb);

	if (cold) {
		howto |= RB_HALT;
		goto haltsys;
	}

	/* If "always halt" was specified as a boot flag, obey. */
	if (boothowto & RB_HALT)
		howto |= RB_HALT;

	boothowto = howto;
	if ((howto & RB_NOSYNC) == 0 && (waittime < 0)) {
		waittime = 0;
		vfs_shutdown();

		/*
		 * If we've been adjusting the clock, the todr
		 * will be out of synch; adjust it now.
		 */
		resettodr();
	}

	splhigh();

	if (howto & RB_DUMP)
		dumpsys();

 haltsys:
	doshutdownhooks();

	pmf_system_shutdown(boothowto);

	if (howto & RB_HALT) {
		printf("\n");
		printf("The operating system has halted.\n");
		printf("Please press any key to reboot.\n\n");
		cnpollc(1);	/* For proper keyboard command handling */
		cngetc();
		cnpollc(0);
	}

	printf("rebooting...\n\n");
	delay(500000);

	*(volatile char *)MIPS_PHYS_TO_KSEG1(LED_ADDR) = LED_RESET;
	printf("WARNING: reboot failed!\n");

	for (;;)
		;
}

__dead void
boot(int howto)
{
	if (cold) {
		if ((howto & RB_USERREQ) == 0)
			howto |=  RB_HALT;
		goto haltsys;
	}

	/*
	 * If RB_NOSYNC was not specified sync the discs.
	 * Note: Unless cold is set to 1 here, syslogd will die during the
	 * unmount.  It looks like syslogd is getting woken up only to find
	 * that it cannot page part of the binary in as the filesystem has
	 * been unmounted.
	 */
	if ((howto & RB_NOSYNC) == 0)
		bootsync(howto);

	if_downall();

	uvm_shutdown();
	splhigh();
	cold = 1;

	if ((howto & (RB_DUMP | RB_HALT)) == RB_DUMP)
		dumpsys();

haltsys:
	config_suspend_all(DVACT_POWERDOWN);

	/* Make sure IRQ's are disabled */
	IRQdisable;

	if ((howto & RB_HALT) != 0) {
		if ((howto & RB_POWERDOWN) != 0) {
			board_powerdown();
			printf("WARNING: powerdown failed!\n");
		}

		printf("The operating system has halted.\n");
		printf("Please press any key to reboot.\n\n");
		cnpollc(1);
		cngetc();
		cnpollc(0);
	}

	printf("rebooting...\n");

	board_reset();
	cpu_reset();
	printf("reboot failed; spinning\n");
	for (;;) ;
	/* NOTREACHED */
}

/*
 * XXX we know that scankbd is only called from read/write to interrupt
 * a boot program.  Since we restart only on ^C and we do that here, we
 * always return 0 to avoid a longjmp in the caller.
 */
scankbd()
{
	register int c;

	c = cngetc();
	if (c == ('c'&037)) {
		printf("^C");
		_stop("");
		/* NOTREACHED */
	}
	return(0);
}

int 
kmgetc_silent(
	__unused dev_t dev)
{
	int c;
	
	c= cngetc();
	if (c == '\r') {
		c = '\n';
	}
	return c;
}

static int
ramd_norm_read(struct read_info *rsp)
{
	long		bytes_left;
	int		done, error;
	struct buf	*bp;
	int		dotc = 0;

	bytes_left = rsp->nbytes;
	bp         = rsp->bp;
	error      = 0;

	while (bytes_left > 0) {
		bp->b_cflags = BC_BUSY;
		bp->b_flags  = B_PHYS | B_READ;
		bp->b_oflags &= ~BO_DONE;
		bp->b_blkno  = btodb(rsp->offset);
		bp->b_bcount = min(rsp->chunk, bytes_left);
		bp->b_data   = rsp->bufp;
		bp->b_error  = 0;

		/* Initiate read */
		(*rsp->strat)(bp);

		/* Wait for results	*/
		biowait(bp);
		error = bp->b_error;

		/* Dot counter */
		printf(".");
		if (!(++dotc % 40))
			printf("\n");

		done = bp->b_bcount - bp->b_resid;

		bytes_left   -= done;
		rsp->offset  += done;
		rsp->bufp    += done;

		if (error || !done)
			break;

		if ((rsp->offset == rsp->media_sz) && (bytes_left != 0)) {
			printf("\nInsert next media and hit any key...");
			cngetc();
			printf("\n");
			rsp->offset = 0;
		}
	}
	printf("\n");
	return error;
}

/*
 * Read a maximum of 'nbyte' bytes into 'buf'.
 */
static int
md_compressed(void * buf, int nbyte, struct read_info *rsp)
{
	static int	dotc = 0;
	struct buf	*bp;
	       int	nread = 0;
	       int	done, error;


	error  = 0;
	bp     = rsp->bp;
	nbyte &= ~(DEV_BSIZE - 1);

	while (nbyte > 0) {
		bp->b_cflags = BC_BUSY;
		bp->b_flags  = B_PHYS | B_READ;
		bp->b_oflags &= ~BO_DONE;
		bp->b_blkno  = btodb(rsp->offset);
		bp->b_bcount = min(rsp->chunk, nbyte);
		bp->b_data   = buf;
		bp->b_error  = 0;

		/* Initiate read */
		(*rsp->strat)(bp);

		/* Wait for results	*/
		biowait(bp);
		error = bp->b_error;

		/* Dot counter */
		printf(".");
		if (!(++dotc % 40))
			printf("\n");

		done = bp->b_bcount - bp->b_resid;

		nbyte        -= done;
		nread        += done;
		rsp->offset  += done;

		if (error || !done)
			break;

		if ((rsp->offset == rsp->media_sz) && (nbyte != 0)) {
			printf("\nInsert next media and hit any key...");
			if (cngetc() != '\n')
				printf("\n");
			rsp->offset = 0;
		}
	}
	return nread;
}

int 
kmgetc(__unused dev_t dev)
{
	int c;
	
	c= cngetc();

	if (c == '\r') {
		c = '\n';
	}
	cnputcusr(c);
	return c;
}

/*
 * A simple paging callout function.  It supports several simple more(1)-like
 * commands as well as a quit command that sets db_pager_quit which db
 * commands can poll to see if they should terminate early.
 */
void
db_pager(void)
{
	int c, done;

	db_capture_enterpager();
	db_printf("--More--\r");
	done = 0;
	while (!done) {
		c = cngetc();
		switch (c) {
		case 'e':
		case 'j':
		case '\n':
			/* Just one more line. */
			db_maxlines = 1;
			done++;
			break;
		case 'd':
			/* Half a page. */
			db_maxlines = db_lines_per_page / 2;
			done++;
			break;
		case 'f':
		case ' ':
			/* Another page. */
			db_maxlines = db_lines_per_page;
			done++;
			break;
		case 'q':
		case 'Q':
		case 'x':
		case 'X':
			/* Quit */
			db_maxlines = 0;
			db_pager_quit = 1;
			done++;
			break;
#if 0
			/* FALLTHROUGH */
		default:
			cnputc('\007');
#endif
		}
	}
	db_printf("        ");
	db_force_whitespace();
	db_printf("\r");
	db_newlines = 0;
	db_capture_exitpager();
}