[apple/xnu.git] / osfmk / ppc / serial_console.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/*
 * @APPLE_FREE_COPYRIGHT@
 */

#include <mach_kdb.h>
#include <platforms.h>
#include <serial_console_default.h>

#include <kern/spl.h>
#include <machine/machparam.h>		/* spl definitions */
#include <types.h>
#include <ppc/POWERMAC/video_console_entries.h>
#include <ppc/misc_protos.h>
#include <ppc/POWERMAC/serial_io.h>
#include <ppc/POWERMAC/mp/mp.h>
#include <kern/cpu_number.h>
#include <ppc/Firmware.h>
#include <ppc/proc_reg.h>
#include <pexpert/pexpert.h>

/*
 * A machine MUST have a console.  In our case
 * things are a little complicated by the graphic
 * display: people expect it to be their "console",
 * but we'd like to be able to live without it.
 * This is not to be confused with the "rconsole" thing:
 * that just duplicates the console I/O to
 * another place (for debugging/logging purposes).
 */

const int console_unit = 0;
const int console_chan_default = CONSOLE_PORT;
#define console_chan (console_chan_default) /* ^ cpu_number()) */

#define OPS(putc, getc, nosplputc, nosplgetc) putc, getc

const struct console_ops {
	int	(*putc)(int, int, int);
	int	(*getc)(int, int, boolean_t, boolean_t);
} cons_ops[] = {
#define SCC_CONS_OPS 0
	{OPS(scc_putc, scc_getc, no_spl_scputc, no_spl_scgetc)},
#define VC_CONS_OPS 1
	{OPS(vcputc, vcgetc, no_spl_vcputc, no_spl_vcgetc)},
};
#define NCONSOPS (sizeof cons_ops / sizeof cons_ops[0])

#if SERIAL_CONSOLE_DEFAULT
#define CONS_OPS SCC_CONS_OPS
#define CONS_NAME "com"
#else
#define CONS_OPS VC_CONS_OPS
#define CONS_NAME "vc"
#endif

#define MP_SAFE_CONSOLE 1	/* Set this to 1 to allow more than 1 processor to print at once */
#if MP_SAFE_CONSOLE

struct ppcbfr {													/* Controls multiple processor output */
	unsigned int 	pos;										/* Current position in buffer */
	unsigned int	noprompt;									/* Set if we skip the prompt */
	unsigned int	echo;										/* Control character echoing */
	char			buffer[256];								/* Fairly big buffer */	
};
typedef struct ppcbfr ppcbfr;
ppcbfr cbfr[NCPUS];												/* Get one of these for each processor */
volatile unsigned int cbfpend;									/* A buffer is pending output */
volatile unsigned int sconowner=-1;								/* Mark who's actually writing */

#endif


unsigned int cons_ops_index = CONS_OPS;
unsigned int killprint = 0;
unsigned int debcnputc = 0;
extern unsigned int	mappingdeb0;
extern int debugger_holdoff[NCPUS];

static void _cnputc(char c)
{
	cons_ops[cons_ops_index].putc(console_unit, console_chan, c);
}

void cnputcusr(char c) {										/* Echo input character directly */

	unsigned int cpu;
	
	if (cpu_data[master_cpu].active_thread) cpu = cpu_number();	/* If we're started up, use the current CPU */
	else cpu = master_cpu;										/* Otherwise use the master_cpu */
	
	hw_atomic_add(&debugger_holdoff[cpu], 1);					/* Don't allow debugger entry just now (this is a HACK) */
	
	_cnputc( c);												/* Echo the character */
	if(c=='\n') _cnputc( '\r');									/* Add a return if we had a new line */
	
	hw_atomic_sub(&debugger_holdoff[cpu], 1);					/* Don't allow debugger entry just now (this is a HACK) */
	return;
}

void
cnputc(char c)
{

	unsigned int oldpend, i, cpu, ourbit, sccpu;
	spl_t 		s;
		
#if MP_SAFE_CONSOLE

/*
 *		Handle multiple CPU console output.
 *		Note: this thing has gotten god-awful complicated.  We need a better way.
 */
 	

	if(killprint) {		
		return;													/* If printing is disabled, bail... */
	}	
	
	if (cpu_data[master_cpu].active_thread) cpu = cpu_number();	/* If we're started up, use the current CPU */
	else cpu = master_cpu;										/* Otherwise use the master_cpu */

	hw_atomic_add(&debugger_holdoff[cpu], 1);					/* Don't allow debugger entry just now (this is a HACK) */

	ourbit = 1 << cpu;											/* Make a mask for just us */
	if(debugger_cpu != -1) {									/* Are we in the debugger with empty buffers? */
	
		while(sconowner != cpu) {								/* Anyone but us? */
			hw_compare_and_store(-1, cpu, (unsigned int *)&sconowner);	/* Try to mark it for us if idle */
		}
	
		_cnputc( c);											/* Yeah, just write it */
		if(c=='\n')												/* Did we just write a new line? */
			_cnputc( '\r');										/* Yeah, just add a return */
			
		sconowner=-1;											/* Mark it idle */	
		hw_atomic_sub(&debugger_holdoff[cpu], 1);				/* Don't allow debugger entry just now (this is a HACK) */
		
		return;													/* Leave... */
	}

	s=splhigh();												/* Don't bother me */
	
	while(ourbit&cbfpend);										/* We aren't "double buffered," so we'll just wait until the buffers are written */
	isync();													/* Just in case we had to wait */
	
	if(c) {														/* If the character is not null */
		cbfr[cpu].buffer[cbfr[cpu].pos]=c;						/* Fill in the buffer for our CPU */
		cbfr[cpu].pos++;										/* Up the count */
		if(cbfr[cpu].pos > 253) {								/* Is the buffer full? */
			cbfr[cpu].buffer[254]='\n';							/* Yeah, set the second to last as a LF */
			cbfr[cpu].buffer[255]='\r';							/* And the last to a CR */
			cbfr[cpu].pos=256;									/* Push the buffer to the end */
			c='\r';												/* Set character to a CR */
		}
	}
	
	if(c == '\n') {												/* Are we finishing a line? */
		cbfr[cpu].buffer[cbfr[cpu].pos]='\r';					/* And the last to a CR */
		cbfr[cpu].pos++;										/* Up the count */
		c='\r';													/* Set character to a CR */
	}

#if 1
	if(cbfr[cpu].echo == 1) {									/* Did we hit an escape last time? */
		if(c == 'K') {											/* Is it a partial clear? */
			cbfr[cpu].echo = 2;									/* Yes, enter echo mode */
		}
		else cbfr[cpu].echo = 0;								/* Otherwise reset escape */
	}
	else if(cbfr[cpu].echo == 0) {								/* Not in escape sequence, see if we should enter */
		cbfr[cpu].echo = 1;										/* Set that we are in escape sequence */
	}
#endif

	if((c == 0x00) || (c == '\r') || (cbfr[cpu].echo == 2)) {	/* Try to push out all buffers if we see CR or null */
				
		while(1) {												/* Loop until we see who's doing this */
			oldpend=cbfpend;									/* Get the currentest pending buffer flags */
			if(hw_compare_and_store(oldpend, oldpend|ourbit, (unsigned int *)&cbfpend))	/* Swap ours on if no change */
				break;											/* Bail the loop if it worked */
		}
		
		if(!hw_compare_and_store(-1, cpu, (unsigned int *)&sconowner)) {	/* See if someone else has this, and take it if not */
			debugger_holdoff[cpu] = 0;							/* Allow debugger entry (this is a HACK) */
			splx(s);											/* Let's take some 'rupts now */
			return;												/* We leave here, 'cause another processor is already writing the buffers */
		}
				
		while(1) {												/* Loop to dump out all of the finished buffers */
			oldpend=cbfpend;									/* Get the most current finished buffers */
			for(sccpu=0; sccpu<NCPUS; sccpu++) {				/* Cycle through all CPUs buffers */
				
				if(oldpend&(1<<sccpu)) {						/* Does this guy have a buffer to do? */

#if 0
					if(!cbfr[sccpu].noprompt) {					/* Don't prompt if there was not CR before */
						_cnputc( '{');	/* Mark CPU number */
						_cnputc( '0'+sccpu);	/* Mark CPU number */
						_cnputc( '.');	/* (TEST/DEBUG) */
						_cnputc( '0'+cpu);	/* (TEST/DEBUG) */
						_cnputc( '}');	/* Mark CPU number */
						_cnputc( ' ');	/* Mark CPU number */
					}
#endif
					
					for(i=0; i<cbfr[sccpu].pos; i++) {			/* Do the whole buffer */
						_cnputc( cbfr[sccpu].buffer[i]); /* Write it */
					}
					
					if(cbfr[sccpu].buffer[cbfr[sccpu].pos-1]!='\r') {	/* Was the last character a return? */
						cbfr[sccpu].noprompt = 1;				/* Remember not to prompt */
					}
					else {										/* Last was a return */
						cbfr[sccpu].noprompt = 0;				/* Otherwise remember to prompt */
						cbfr[sccpu].echo = 0;					/* And clear echo */
					}
						
					cbfr[sccpu].pos=0;							/* Reset the buffer pointer */
		
					while(!hw_compare_and_store(cbfpend, cbfpend&~(1<<sccpu), (unsigned int *)&cbfpend));	/* Swap it off */
				}
			}
			sconowner=-1;										/* Set the writer to idle */
			sync();												/* Insure that everything's done */
			if(hw_compare_and_store(0, 0, (unsigned int *)&cbfpend)) break;	/* If there are no new buffers, we are done... */
			if(!hw_compare_and_store(-1, cpu, (unsigned int *)&sconowner)) break;	/* If this isn't idle anymore, we're done */
	
		}
	}
	hw_atomic_sub(&debugger_holdoff[cpu], 1);					/* Don't allow debugger entry just now (this is a HACK) */
	splx(s);													/* Let's take some 'rupts now */

#else  /* MP_SAFE_CONSOLE */
	_cnputc( c);
	if (c == '\n')
		_cnputc('\r');
#endif  /* MP_SAFE_CONSOLE */

}

int
cngetc()
{
	return cons_ops[cons_ops_index].getc(console_unit, console_chan,
					     TRUE, FALSE);
}

int
cnmaygetc()
{
	return cons_ops[cons_ops_index].getc(console_unit, console_chan,
					     FALSE, FALSE);
}

boolean_t console_is_serial()
{
	return cons_ops_index == SCC_CONS_OPS;
}

int
switch_to_video_console()
{
	int old_cons_ops = cons_ops_index;
	cons_ops_index = VC_CONS_OPS;
	return old_cons_ops;
}

int
switch_to_serial_console()
{
	int old_cons_ops = cons_ops_index;
	cons_ops_index = SCC_CONS_OPS;
	return old_cons_ops;
}

/* The switch_to_{video,serial,kgdb}_console functions return a cookie that
   can be used to restore the console to whatever it was before, in the
   same way that splwhatever() and splx() work.  */
void
switch_to_old_console(int old_console)
{
	static boolean_t squawked;
	unsigned int ops = old_console;

	if (ops >= NCONSOPS && !squawked) {
		squawked = TRUE;
		printf("switch_to_old_console: unknown ops %d\n", ops);
	} else
		cons_ops_index = ops;
}


int
vcgetc(int l, int u, boolean_t wait, boolean_t raw)
{
	char c;

	if( 0 == (*PE_poll_input)( 0, &c))
		return( c);
	else
		return( 0);
}
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* @OSF_COPYRIGHT@
	24	*/
	25	/*
	26	* @APPLE_FREE_COPYRIGHT@
	27	*/
	28
	29	#include <mach_kdb.h>
	30	#include <platforms.h>
	31	#include <serial_console_default.h>
	32
	33	#include <kern/spl.h>
	34	#include <machine/machparam.h> /* spl definitions */
	35	#include <types.h>
	36	#include <ppc/POWERMAC/video_console_entries.h>
	37	#include <ppc/misc_protos.h>
	38	#include <ppc/POWERMAC/serial_io.h>
	39	#include <ppc/POWERMAC/mp/mp.h>
	40	#include <kern/cpu_number.h>
	41	#include <ppc/Firmware.h>
	42	#include <ppc/proc_reg.h>
	43	#include <pexpert/pexpert.h>
	44
	45	/*
	46	* A machine MUST have a console. In our case
	47	* things are a little complicated by the graphic
	48	* display: people expect it to be their "console",
	49	* but we'd like to be able to live without it.
	50	* This is not to be confused with the "rconsole" thing:
	51	* that just duplicates the console I/O to
	52	* another place (for debugging/logging purposes).
	53	*/
	54
	55	const int console_unit = 0;
	56	const int console_chan_default = CONSOLE_PORT;
	57	#define console_chan (console_chan_default) /* ^ cpu_number()) */
	58
	59	#define OPS(putc, getc, nosplputc, nosplgetc) putc, getc
	60
	61	const struct console_ops {
	62	int (*putc)(int, int, int);
	63	int (*getc)(int, int, boolean_t, boolean_t);
	64	} cons_ops[] = {
65	#define SCC_CONS_OPS 0
66	{OPS(scc_putc, scc_getc, no_spl_scputc, no_spl_scgetc)},
67	#define VC_CONS_OPS 1
68	{OPS(vcputc, vcgetc, no_spl_vcputc, no_spl_vcgetc)},
69	};
70	#define NCONSOPS (sizeof cons_ops / sizeof cons_ops[0])
71
72	#if SERIAL_CONSOLE_DEFAULT
73	#define CONS_OPS SCC_CONS_OPS
74	#define CONS_NAME "com"
75	#else
76	#define CONS_OPS VC_CONS_OPS
77	#define CONS_NAME "vc"
78	#endif
79
80	#define MP_SAFE_CONSOLE 1 /* Set this to 1 to allow more than 1 processor to print at once */
81	#if MP_SAFE_CONSOLE
82
83	struct ppcbfr { /* Controls multiple processor output */
84	unsigned int pos; /* Current position in buffer */
85	unsigned int noprompt; /* Set if we skip the prompt */
86	unsigned int echo; /* Control character echoing */
87	char buffer[256]; /* Fairly big buffer */
88	};
89	typedef struct ppcbfr ppcbfr;
90	ppcbfr cbfr[NCPUS]; /* Get one of these for each processor */
91	volatile unsigned int cbfpend; /* A buffer is pending output */
92	volatile unsigned int sconowner=-1; /* Mark who's actually writing */
93
94	#endif
95
96
97	unsigned int cons_ops_index = CONS_OPS;
98	unsigned int killprint = 0;
99	unsigned int debcnputc = 0;
100	extern unsigned int mappingdeb0;
101	extern int debugger_holdoff[NCPUS];
102
103	static void _cnputc(char c)
104	{
105	cons_ops[cons_ops_index].putc(console_unit, console_chan, c);
106	}
107
108	void cnputcusr(char c) { /* Echo input character directly */
109
110	unsigned int cpu;
111
112	if (cpu_data[master_cpu].active_thread) cpu = cpu_number(); /* If we're started up, use the current CPU */
113	else cpu = master_cpu; /* Otherwise use the master_cpu */
114
115	hw_atomic_add(&debugger_holdoff[cpu], 1); /* Don't allow debugger entry just now (this is a HACK) */
116
117	_cnputc( c); /* Echo the character */
118	if(c=='\n') _cnputc( '\r'); /* Add a return if we had a new line */
119
120	hw_atomic_sub(&debugger_holdoff[cpu], 1); /* Don't allow debugger entry just now (this is a HACK) */
121	return;
122	}
123
124	void
125	cnputc(char c)
126	{
127
128	unsigned int oldpend, i, cpu, ourbit, sccpu;
129	spl_t s;
130
131	#if MP_SAFE_CONSOLE
132
133	/*
134	* Handle multiple CPU console output.
135	* Note: this thing has gotten god-awful complicated. We need a better way.
136	*/
137
138
139	if(killprint) {
140	return; /* If printing is disabled, bail... */
141	}
142
143	if (cpu_data[master_cpu].active_thread) cpu = cpu_number(); /* If we're started up, use the current CPU */
144	else cpu = master_cpu; /* Otherwise use the master_cpu */
145
146	hw_atomic_add(&debugger_holdoff[cpu], 1); /* Don't allow debugger entry just now (this is a HACK) */
147
148	ourbit = 1 << cpu; /* Make a mask for just us */
149	if(debugger_cpu != -1) { /* Are we in the debugger with empty buffers? */
150
151	while(sconowner != cpu) { /* Anyone but us? */
152	hw_compare_and_store(-1, cpu, (unsigned int )&sconowner); / Try to mark it for us if idle */
153	}
154
155	_cnputc( c); /* Yeah, just write it */
156	if(c=='\n') /* Did we just write a new line? */
157	_cnputc( '\r'); /* Yeah, just add a return */
158
159	sconowner=-1; /* Mark it idle */
160	hw_atomic_sub(&debugger_holdoff[cpu], 1); /* Don't allow debugger entry just now (this is a HACK) */
161
162	return; /* Leave... */
163	}
164
165	s=splhigh(); /* Don't bother me */
166
167	while(ourbit&cbfpend); /* We aren't "double buffered," so we'll just wait until the buffers are written */
168	isync(); /* Just in case we had to wait */
169
170	if(c) { /* If the character is not null */
171	cbfr[cpu].buffer[cbfr[cpu].pos]=c; /* Fill in the buffer for our CPU */
172	cbfr[cpu].pos++; /* Up the count */
173	if(cbfr[cpu].pos > 253) { /* Is the buffer full? */
174	cbfr[cpu].buffer[254]='\n'; /* Yeah, set the second to last as a LF */
175	cbfr[cpu].buffer[255]='\r'; /* And the last to a CR */
176	cbfr[cpu].pos=256; /* Push the buffer to the end */
177	c='\r'; /* Set character to a CR */
178	}
179	}
180
181	if(c == '\n') { /* Are we finishing a line? */
182	cbfr[cpu].buffer[cbfr[cpu].pos]='\r'; /* And the last to a CR */
183	cbfr[cpu].pos++; /* Up the count */
184	c='\r'; /* Set character to a CR */
185	}
186
187	#if 1
188	if(cbfr[cpu].echo == 1) { /* Did we hit an escape last time? */
189	if(c == 'K') { /* Is it a partial clear? */
190	cbfr[cpu].echo = 2; /* Yes, enter echo mode */
191	}
192	else cbfr[cpu].echo = 0; /* Otherwise reset escape */
193	}
194	else if(cbfr[cpu].echo == 0) { /* Not in escape sequence, see if we should enter */
195	cbfr[cpu].echo = 1; /* Set that we are in escape sequence */
196	}
197	#endif
198
199	if((c == 0x00) \|\| (c == '\r') \|\| (cbfr[cpu].echo == 2)) { /* Try to push out all buffers if we see CR or null */
200
201	while(1) { /* Loop until we see who's doing this */
202	oldpend=cbfpend; /* Get the currentest pending buffer flags */
203	if(hw_compare_and_store(oldpend, oldpend\|ourbit, (unsigned int )&cbfpend)) / Swap ours on if no change */
204	break; /* Bail the loop if it worked */
205	}
206
207	if(!hw_compare_and_store(-1, cpu, (unsigned int )&sconowner)) { / See if someone else has this, and take it if not */
208	debugger_holdoff[cpu] = 0; /* Allow debugger entry (this is a HACK) */
209	splx(s); /* Let's take some 'rupts now */
210	return; /* We leave here, 'cause another processor is already writing the buffers */
211	}
212
213	while(1) { /* Loop to dump out all of the finished buffers */
214	oldpend=cbfpend; /* Get the most current finished buffers */
215	for(sccpu=0; sccpu<NCPUS; sccpu++) { /* Cycle through all CPUs buffers */
216
217	if(oldpend&(1<<sccpu)) { /* Does this guy have a buffer to do? */
218
219	#if 0
220	if(!cbfr[sccpu].noprompt) { /* Don't prompt if there was not CR before */
221	_cnputc( '{'); /* Mark CPU number */
222	_cnputc( '0'+sccpu); /* Mark CPU number */
223	_cnputc( '.'); /* (TEST/DEBUG) */
224	_cnputc( '0'+cpu); /* (TEST/DEBUG) */
225	_cnputc( '}'); /* Mark CPU number */
226	_cnputc( ' '); /* Mark CPU number */
227	}
228	#endif
229
230	for(i=0; i<cbfr[sccpu].pos; i++) { /* Do the whole buffer */
231	_cnputc( cbfr[sccpu].buffer[i]); /* Write it */
232	}
233
234	if(cbfr[sccpu].buffer[cbfr[sccpu].pos-1]!='\r') { /* Was the last character a return? */
235	cbfr[sccpu].noprompt = 1; /* Remember not to prompt */
236	}
237	else { /* Last was a return */
238	cbfr[sccpu].noprompt = 0; /* Otherwise remember to prompt */
239	cbfr[sccpu].echo = 0; /* And clear echo */
240	}
241
242	cbfr[sccpu].pos=0; /* Reset the buffer pointer */
243
244	while(!hw_compare_and_store(cbfpend, cbfpend&~(1<<sccpu), (unsigned int )&cbfpend)); / Swap it off */
245	}
246	}
247	sconowner=-1; /* Set the writer to idle */
248	sync(); /* Insure that everything's done */
249	if(hw_compare_and_store(0, 0, (unsigned int )&cbfpend)) break; / If there are no new buffers, we are done... */
250	if(!hw_compare_and_store(-1, cpu, (unsigned int )&sconowner)) break; / If this isn't idle anymore, we're done */
251
252	}
253	}
254	hw_atomic_sub(&debugger_holdoff[cpu], 1); /* Don't allow debugger entry just now (this is a HACK) */
255	splx(s); /* Let's take some 'rupts now */
256
257	#else /* MP_SAFE_CONSOLE */
258	_cnputc( c);
259	if (c == '\n')
260	_cnputc('\r');
261	#endif /* MP_SAFE_CONSOLE */
262
263	}
264
265	int
266	cngetc()
267	{
268	return cons_ops[cons_ops_index].getc(console_unit, console_chan,
269	TRUE, FALSE);
270	}
271
272	int
273	cnmaygetc()
274	{
275	return cons_ops[cons_ops_index].getc(console_unit, console_chan,
276	FALSE, FALSE);
277	}
278
279	boolean_t console_is_serial()
280	{
281	return cons_ops_index == SCC_CONS_OPS;
282	}
283
284	int
285	switch_to_video_console()
286	{
287	int old_cons_ops = cons_ops_index;
288	cons_ops_index = VC_CONS_OPS;
289	return old_cons_ops;
290	}
291
292	int
293	switch_to_serial_console()
294	{
295	int old_cons_ops = cons_ops_index;
296	cons_ops_index = SCC_CONS_OPS;
297	return old_cons_ops;
298	}
299
300	/* The switch_to_{video,serial,kgdb}_console functions return a cookie that
301	can be used to restore the console to whatever it was before, in the
302	same way that splwhatever() and splx() work. */
303	void
304	switch_to_old_console(int old_console)
305	{
306	static boolean_t squawked;
307	unsigned int ops = old_console;
308
309	if (ops >= NCONSOPS && !squawked) {
310	squawked = TRUE;
311	printf("switch_to_old_console: unknown ops %d\n", ops);
312	} else
313	cons_ops_index = ops;
314	}
315
316
317	int
318	vcgetc(int l, int u, boolean_t wait, boolean_t raw)
319	{
320	char c;
321
322	if( 0 == (*PE_poll_input)( 0, &c))
323	return( c);
324	else
325	return( 0);
326	}