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v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/console.h>
  3#include <linux/kernel.h>
  4#include <linux/init.h>
  5#include <linux/string.h>
  6#include <linux/screen_info.h>
  7#include <linux/usb/ch9.h>
  8#include <linux/pci_regs.h>
  9#include <linux/pci_ids.h>
 10#include <linux/errno.h>
 11#include <linux/pgtable.h>
 12#include <asm/io.h>
 13#include <asm/processor.h>
 14#include <asm/fcntl.h>
 15#include <asm/setup.h>
 16#include <xen/hvc-console.h>
 17#include <asm/pci-direct.h>
 18#include <asm/fixmap.h>
 
 
 19#include <linux/usb/ehci_def.h>
 20#include <linux/usb/xhci-dbgp.h>
 
 21#include <asm/pci_x86.h>
 22
 23/* Simple VGA output */
 24#define VGABASE		(__ISA_IO_base + 0xb8000)
 25
 26static int max_ypos = 25, max_xpos = 80;
 27static int current_ypos = 25, current_xpos;
 28
 29static void early_vga_write(struct console *con, const char *str, unsigned n)
 30{
 31	char c;
 32	int  i, k, j;
 33
 34	while ((c = *str++) != '\0' && n-- > 0) {
 35		if (current_ypos >= max_ypos) {
 36			/* scroll 1 line up */
 37			for (k = 1, j = 0; k < max_ypos; k++, j++) {
 38				for (i = 0; i < max_xpos; i++) {
 39					writew(readw(VGABASE+2*(max_xpos*k+i)),
 40					       VGABASE + 2*(max_xpos*j + i));
 41				}
 42			}
 43			for (i = 0; i < max_xpos; i++)
 44				writew(0x720, VGABASE + 2*(max_xpos*j + i));
 45			current_ypos = max_ypos-1;
 46		}
 47#ifdef CONFIG_KGDB_KDB
 48		if (c == '\b') {
 49			if (current_xpos > 0)
 50				current_xpos--;
 51		} else if (c == '\r') {
 52			current_xpos = 0;
 53		} else
 54#endif
 55		if (c == '\n') {
 56			current_xpos = 0;
 57			current_ypos++;
 58		} else if (c != '\r')  {
 59			writew(((0x7 << 8) | (unsigned short) c),
 60			       VGABASE + 2*(max_xpos*current_ypos +
 61						current_xpos++));
 62			if (current_xpos >= max_xpos) {
 63				current_xpos = 0;
 64				current_ypos++;
 65			}
 66		}
 67	}
 68}
 69
 70static struct console early_vga_console = {
 71	.name =		"earlyvga",
 72	.write =	early_vga_write,
 73	.flags =	CON_PRINTBUFFER,
 74	.index =	-1,
 75};
 76
 77/* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
 78
 79static unsigned long early_serial_base = 0x3f8;  /* ttyS0 */
 80
 81#define XMTRDY          0x20
 82
 83#define DLAB		0x80
 84
 85#define TXR             0       /*  Transmit register (WRITE) */
 86#define RXR             0       /*  Receive register  (READ)  */
 87#define IER             1       /*  Interrupt Enable          */
 88#define IIR             2       /*  Interrupt ID              */
 89#define FCR             2       /*  FIFO control              */
 90#define LCR             3       /*  Line control              */
 91#define MCR             4       /*  Modem control             */
 92#define LSR             5       /*  Line Status               */
 93#define MSR             6       /*  Modem Status              */
 94#define DLL             0       /*  Divisor Latch Low         */
 95#define DLH             1       /*  Divisor latch High        */
 96
 97static unsigned int io_serial_in(unsigned long addr, int offset)
 98{
 99	return inb(addr + offset);
100}
101
102static void io_serial_out(unsigned long addr, int offset, int value)
103{
104	outb(value, addr + offset);
105}
106
107static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
108static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
109
110static int early_serial_putc(unsigned char ch)
111{
112	unsigned timeout = 0xffff;
113
114	while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
115		cpu_relax();
116	serial_out(early_serial_base, TXR, ch);
117	return timeout ? 0 : -1;
118}
119
120static void early_serial_write(struct console *con, const char *s, unsigned n)
121{
122	while (*s && n-- > 0) {
123		if (*s == '\n')
124			early_serial_putc('\r');
125		early_serial_putc(*s);
126		s++;
127	}
128}
129
130static __init void early_serial_hw_init(unsigned divisor)
131{
132	unsigned char c;
133
134	serial_out(early_serial_base, LCR, 0x3);	/* 8n1 */
135	serial_out(early_serial_base, IER, 0);	/* no interrupt */
136	serial_out(early_serial_base, FCR, 0);	/* no fifo */
137	serial_out(early_serial_base, MCR, 0x3);	/* DTR + RTS */
138
139	c = serial_in(early_serial_base, LCR);
140	serial_out(early_serial_base, LCR, c | DLAB);
141	serial_out(early_serial_base, DLL, divisor & 0xff);
142	serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
143	serial_out(early_serial_base, LCR, c & ~DLAB);
144}
145
146#define DEFAULT_BAUD 9600
147
148static __init void early_serial_init(char *s)
149{
150	unsigned divisor;
151	unsigned long baud = DEFAULT_BAUD;
152	char *e;
153
154	if (*s == ',')
155		++s;
156
157	if (*s) {
158		unsigned port;
159		if (!strncmp(s, "0x", 2)) {
160			early_serial_base = simple_strtoul(s, &e, 16);
161		} else {
162			static const int __initconst bases[] = { 0x3f8, 0x2f8 };
163
164			if (!strncmp(s, "ttyS", 4))
165				s += 4;
166			port = simple_strtoul(s, &e, 10);
167			if (port > 1 || s == e)
168				port = 0;
169			early_serial_base = bases[port];
170		}
171		s += strcspn(s, ",");
172		if (*s == ',')
173			s++;
174	}
175
176	if (*s) {
177		baud = simple_strtoull(s, &e, 0);
178
179		if (baud == 0 || s == e)
180			baud = DEFAULT_BAUD;
181	}
182
183	/* Convert from baud to divisor value */
184	divisor = 115200 / baud;
185
186	/* These will always be IO based ports */
187	serial_in = io_serial_in;
188	serial_out = io_serial_out;
189
190	/* Set up the HW */
191	early_serial_hw_init(divisor);
192}
193
194#ifdef CONFIG_PCI
195static void mem32_serial_out(unsigned long addr, int offset, int value)
196{
197	u32 __iomem *vaddr = (u32 __iomem *)addr;
198	/* shift implied by pointer type */
199	writel(value, vaddr + offset);
200}
201
202static unsigned int mem32_serial_in(unsigned long addr, int offset)
203{
204	u32 __iomem *vaddr = (u32 __iomem *)addr;
205	/* shift implied by pointer type */
206	return readl(vaddr + offset);
207}
208
209/*
210 * early_pci_serial_init()
211 *
212 * This function is invoked when the early_printk param starts with "pciserial"
213 * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe
214 * the location of a PCI device that must be a UART device. "force" is optional
215 * and overrides the use of an UART device with a wrong PCI class code.
216 */
217static __init void early_pci_serial_init(char *s)
218{
219	unsigned divisor;
220	unsigned long baud = DEFAULT_BAUD;
221	u8 bus, slot, func;
222	u32 classcode, bar0;
223	u16 cmdreg;
224	char *e;
225	int force = 0;
226
 
 
 
 
227	if (*s == ',')
228		++s;
229
230	if (*s == 0)
231		return;
232
233	/* Force the use of an UART device with wrong class code */
234	if (!strncmp(s, "force,", 6)) {
235		force = 1;
236		s += 6;
237	}
238
239	/*
240	 * Part the param to get the BDF values
241	 */
242	bus = (u8)simple_strtoul(s, &e, 16);
243	s = e;
244	if (*s != ':')
245		return;
246	++s;
247	slot = (u8)simple_strtoul(s, &e, 16);
248	s = e;
249	if (*s != '.')
250		return;
251	++s;
252	func = (u8)simple_strtoul(s, &e, 16);
253	s = e;
254
255	/* A baud might be following */
256	if (*s == ',')
257		s++;
258
259	/*
260	 * Find the device from the BDF
261	 */
262	cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
263	classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
264	bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
265
266	/*
267	 * Verify it is a 16550-UART type device
268	 */
269	if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
270	     (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
271	    (((classcode >> 8) & 0xff) != PCI_SERIAL_16550_COMPATIBLE)) {
272		if (!force)
273			return;
274	}
275
276	/*
277	 * Determine if it is IO or memory mapped
278	 */
279	if ((bar0 & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
280		/* it is IO mapped */
281		serial_in = io_serial_in;
282		serial_out = io_serial_out;
283		early_serial_base = bar0 & PCI_BASE_ADDRESS_IO_MASK;
284		write_pci_config(bus, slot, func, PCI_COMMAND,
285				 cmdreg|PCI_COMMAND_IO);
286	} else {
287		/* It is memory mapped - assume 32-bit alignment */
288		serial_in = mem32_serial_in;
289		serial_out = mem32_serial_out;
290		/* WARNING! assuming the address is always in the first 4G */
291		early_serial_base =
292			(unsigned long)early_ioremap(bar0 & PCI_BASE_ADDRESS_MEM_MASK, 0x10);
293		write_pci_config(bus, slot, func, PCI_COMMAND,
294				 cmdreg|PCI_COMMAND_MEMORY);
295	}
296
297	/*
298	 * Initialize the hardware
299	 */
300	if (*s) {
301		if (strcmp(s, "nocfg") == 0)
302			/* Sometimes, we want to leave the UART alone
303			 * and assume the BIOS has set it up correctly.
304			 * "nocfg" tells us this is the case, and we
305			 * should do no more setup.
306			 */
307			return;
308		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
309			baud = DEFAULT_BAUD;
310	}
311
312	/* Convert from baud to divisor value */
313	divisor = 115200 / baud;
314
315	/* Set up the HW */
316	early_serial_hw_init(divisor);
317}
318#endif
319
320static struct console early_serial_console = {
321	.name =		"earlyser",
322	.write =	early_serial_write,
323	.flags =	CON_PRINTBUFFER,
324	.index =	-1,
325};
326
327static void early_console_register(struct console *con, int keep_early)
328{
329	if (con->index != -1) {
330		printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
331		       con->name);
332		return;
333	}
334	early_console = con;
335	if (keep_early)
336		early_console->flags &= ~CON_BOOT;
337	else
338		early_console->flags |= CON_BOOT;
339	register_console(early_console);
340}
341
342static int __init setup_early_printk(char *buf)
343{
344	int keep;
345
346	if (!buf)
347		return 0;
348
349	if (early_console)
350		return 0;
351
352	keep = (strstr(buf, "keep") != NULL);
353
354	while (*buf != '\0') {
355		if (!strncmp(buf, "serial", 6)) {
356			buf += 6;
357			early_serial_init(buf);
358			early_console_register(&early_serial_console, keep);
359			if (!strncmp(buf, ",ttyS", 5))
360				buf += 5;
361		}
362		if (!strncmp(buf, "ttyS", 4)) {
363			early_serial_init(buf + 4);
364			early_console_register(&early_serial_console, keep);
365		}
366#ifdef CONFIG_PCI
367		if (!strncmp(buf, "pciserial", 9)) {
368			early_pci_serial_init(buf + 9);
369			early_console_register(&early_serial_console, keep);
370			buf += 9; /* Keep from match the above "serial" */
371		}
372#endif
373		if (!strncmp(buf, "vga", 3) &&
374		    boot_params.screen_info.orig_video_isVGA == 1) {
375			max_xpos = boot_params.screen_info.orig_video_cols;
376			max_ypos = boot_params.screen_info.orig_video_lines;
377			current_ypos = boot_params.screen_info.orig_y;
378			early_console_register(&early_vga_console, keep);
379		}
380#ifdef CONFIG_EARLY_PRINTK_DBGP
381		if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
382			early_console_register(&early_dbgp_console, keep);
383#endif
384#ifdef CONFIG_HVC_XEN
385		if (!strncmp(buf, "xen", 3))
386			early_console_register(&xenboot_console, keep);
387#endif
388#ifdef CONFIG_EARLY_PRINTK_USB_XDBC
389		if (!strncmp(buf, "xdbc", 4))
390			early_xdbc_parse_parameter(buf + 4, keep);
391#endif
392
393		buf++;
394	}
395	return 0;
396}
397
398early_param("earlyprintk", setup_early_printk);
v4.6
 
  1#include <linux/console.h>
  2#include <linux/kernel.h>
  3#include <linux/init.h>
  4#include <linux/string.h>
  5#include <linux/screen_info.h>
  6#include <linux/usb/ch9.h>
  7#include <linux/pci_regs.h>
  8#include <linux/pci_ids.h>
  9#include <linux/errno.h>
 
 10#include <asm/io.h>
 11#include <asm/processor.h>
 12#include <asm/fcntl.h>
 13#include <asm/setup.h>
 14#include <xen/hvc-console.h>
 15#include <asm/pci-direct.h>
 16#include <asm/fixmap.h>
 17#include <asm/intel-mid.h>
 18#include <asm/pgtable.h>
 19#include <linux/usb/ehci_def.h>
 20#include <linux/efi.h>
 21#include <asm/efi.h>
 22#include <asm/pci_x86.h>
 23
 24/* Simple VGA output */
 25#define VGABASE		(__ISA_IO_base + 0xb8000)
 26
 27static int max_ypos = 25, max_xpos = 80;
 28static int current_ypos = 25, current_xpos;
 29
 30static void early_vga_write(struct console *con, const char *str, unsigned n)
 31{
 32	char c;
 33	int  i, k, j;
 34
 35	while ((c = *str++) != '\0' && n-- > 0) {
 36		if (current_ypos >= max_ypos) {
 37			/* scroll 1 line up */
 38			for (k = 1, j = 0; k < max_ypos; k++, j++) {
 39				for (i = 0; i < max_xpos; i++) {
 40					writew(readw(VGABASE+2*(max_xpos*k+i)),
 41					       VGABASE + 2*(max_xpos*j + i));
 42				}
 43			}
 44			for (i = 0; i < max_xpos; i++)
 45				writew(0x720, VGABASE + 2*(max_xpos*j + i));
 46			current_ypos = max_ypos-1;
 47		}
 48#ifdef CONFIG_KGDB_KDB
 49		if (c == '\b') {
 50			if (current_xpos > 0)
 51				current_xpos--;
 52		} else if (c == '\r') {
 53			current_xpos = 0;
 54		} else
 55#endif
 56		if (c == '\n') {
 57			current_xpos = 0;
 58			current_ypos++;
 59		} else if (c != '\r')  {
 60			writew(((0x7 << 8) | (unsigned short) c),
 61			       VGABASE + 2*(max_xpos*current_ypos +
 62						current_xpos++));
 63			if (current_xpos >= max_xpos) {
 64				current_xpos = 0;
 65				current_ypos++;
 66			}
 67		}
 68	}
 69}
 70
 71static struct console early_vga_console = {
 72	.name =		"earlyvga",
 73	.write =	early_vga_write,
 74	.flags =	CON_PRINTBUFFER,
 75	.index =	-1,
 76};
 77
 78/* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
 79
 80static unsigned long early_serial_base = 0x3f8;  /* ttyS0 */
 81
 82#define XMTRDY          0x20
 83
 84#define DLAB		0x80
 85
 86#define TXR             0       /*  Transmit register (WRITE) */
 87#define RXR             0       /*  Receive register  (READ)  */
 88#define IER             1       /*  Interrupt Enable          */
 89#define IIR             2       /*  Interrupt ID              */
 90#define FCR             2       /*  FIFO control              */
 91#define LCR             3       /*  Line control              */
 92#define MCR             4       /*  Modem control             */
 93#define LSR             5       /*  Line Status               */
 94#define MSR             6       /*  Modem Status              */
 95#define DLL             0       /*  Divisor Latch Low         */
 96#define DLH             1       /*  Divisor latch High        */
 97
 98static unsigned int io_serial_in(unsigned long addr, int offset)
 99{
100	return inb(addr + offset);
101}
102
103static void io_serial_out(unsigned long addr, int offset, int value)
104{
105	outb(value, addr + offset);
106}
107
108static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
109static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
110
111static int early_serial_putc(unsigned char ch)
112{
113	unsigned timeout = 0xffff;
114
115	while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
116		cpu_relax();
117	serial_out(early_serial_base, TXR, ch);
118	return timeout ? 0 : -1;
119}
120
121static void early_serial_write(struct console *con, const char *s, unsigned n)
122{
123	while (*s && n-- > 0) {
124		if (*s == '\n')
125			early_serial_putc('\r');
126		early_serial_putc(*s);
127		s++;
128	}
129}
130
131static __init void early_serial_hw_init(unsigned divisor)
132{
133	unsigned char c;
134
135	serial_out(early_serial_base, LCR, 0x3);	/* 8n1 */
136	serial_out(early_serial_base, IER, 0);	/* no interrupt */
137	serial_out(early_serial_base, FCR, 0);	/* no fifo */
138	serial_out(early_serial_base, MCR, 0x3);	/* DTR + RTS */
139
140	c = serial_in(early_serial_base, LCR);
141	serial_out(early_serial_base, LCR, c | DLAB);
142	serial_out(early_serial_base, DLL, divisor & 0xff);
143	serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
144	serial_out(early_serial_base, LCR, c & ~DLAB);
145}
146
147#define DEFAULT_BAUD 9600
148
149static __init void early_serial_init(char *s)
150{
151	unsigned divisor;
152	unsigned long baud = DEFAULT_BAUD;
153	char *e;
154
155	if (*s == ',')
156		++s;
157
158	if (*s) {
159		unsigned port;
160		if (!strncmp(s, "0x", 2)) {
161			early_serial_base = simple_strtoul(s, &e, 16);
162		} else {
163			static const int __initconst bases[] = { 0x3f8, 0x2f8 };
164
165			if (!strncmp(s, "ttyS", 4))
166				s += 4;
167			port = simple_strtoul(s, &e, 10);
168			if (port > 1 || s == e)
169				port = 0;
170			early_serial_base = bases[port];
171		}
172		s += strcspn(s, ",");
173		if (*s == ',')
174			s++;
175	}
176
177	if (*s) {
178		baud = simple_strtoull(s, &e, 0);
179
180		if (baud == 0 || s == e)
181			baud = DEFAULT_BAUD;
182	}
183
184	/* Convert from baud to divisor value */
185	divisor = 115200 / baud;
186
187	/* These will always be IO based ports */
188	serial_in = io_serial_in;
189	serial_out = io_serial_out;
190
191	/* Set up the HW */
192	early_serial_hw_init(divisor);
193}
194
195#ifdef CONFIG_PCI
196static void mem32_serial_out(unsigned long addr, int offset, int value)
197{
198	u32 __iomem *vaddr = (u32 __iomem *)addr;
199	/* shift implied by pointer type */
200	writel(value, vaddr + offset);
201}
202
203static unsigned int mem32_serial_in(unsigned long addr, int offset)
204{
205	u32 __iomem *vaddr = (u32 __iomem *)addr;
206	/* shift implied by pointer type */
207	return readl(vaddr + offset);
208}
209
210/*
211 * early_pci_serial_init()
212 *
213 * This function is invoked when the early_printk param starts with "pciserial"
214 * The rest of the param should be ",B:D.F,baud" where B, D & F describe the
215 * location of a PCI device that must be a UART device.
 
216 */
217static __init void early_pci_serial_init(char *s)
218{
219	unsigned divisor;
220	unsigned long baud = DEFAULT_BAUD;
221	u8 bus, slot, func;
222	u32 classcode, bar0;
223	u16 cmdreg;
224	char *e;
 
225
226
227	/*
228	 * First, part the param to get the BDF values
229	 */
230	if (*s == ',')
231		++s;
232
233	if (*s == 0)
234		return;
235
 
 
 
 
 
 
 
 
 
236	bus = (u8)simple_strtoul(s, &e, 16);
237	s = e;
238	if (*s != ':')
239		return;
240	++s;
241	slot = (u8)simple_strtoul(s, &e, 16);
242	s = e;
243	if (*s != '.')
244		return;
245	++s;
246	func = (u8)simple_strtoul(s, &e, 16);
247	s = e;
248
249	/* A baud might be following */
250	if (*s == ',')
251		s++;
252
253	/*
254	 * Second, find the device from the BDF
255	 */
256	cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
257	classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
258	bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
259
260	/*
261	 * Verify it is a UART type device
262	 */
263	if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
264	     (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
265	   (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */
266		return;
 
 
267
268	/*
269	 * Determine if it is IO or memory mapped
270	 */
271	if (bar0 & 0x01) {
272		/* it is IO mapped */
273		serial_in = io_serial_in;
274		serial_out = io_serial_out;
275		early_serial_base = bar0&0xfffffffc;
276		write_pci_config(bus, slot, func, PCI_COMMAND,
277						cmdreg|PCI_COMMAND_IO);
278	} else {
279		/* It is memory mapped - assume 32-bit alignment */
280		serial_in = mem32_serial_in;
281		serial_out = mem32_serial_out;
282		/* WARNING! assuming the address is always in the first 4G */
283		early_serial_base =
284			(unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
285		write_pci_config(bus, slot, func, PCI_COMMAND,
286						cmdreg|PCI_COMMAND_MEMORY);
287	}
288
289	/*
290	 * Lastly, initialize the hardware
291	 */
292	if (*s) {
293		if (strcmp(s, "nocfg") == 0)
294			/* Sometimes, we want to leave the UART alone
295			 * and assume the BIOS has set it up correctly.
296			 * "nocfg" tells us this is the case, and we
297			 * should do no more setup.
298			 */
299			return;
300		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
301			baud = DEFAULT_BAUD;
302	}
303
304	/* Convert from baud to divisor value */
305	divisor = 115200 / baud;
306
307	/* Set up the HW */
308	early_serial_hw_init(divisor);
309}
310#endif
311
312static struct console early_serial_console = {
313	.name =		"earlyser",
314	.write =	early_serial_write,
315	.flags =	CON_PRINTBUFFER,
316	.index =	-1,
317};
318
319static void early_console_register(struct console *con, int keep_early)
320{
321	if (con->index != -1) {
322		printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
323		       con->name);
324		return;
325	}
326	early_console = con;
327	if (keep_early)
328		early_console->flags &= ~CON_BOOT;
329	else
330		early_console->flags |= CON_BOOT;
331	register_console(early_console);
332}
333
334static int __init setup_early_printk(char *buf)
335{
336	int keep;
337
338	if (!buf)
339		return 0;
340
341	if (early_console)
342		return 0;
343
344	keep = (strstr(buf, "keep") != NULL);
345
346	while (*buf != '\0') {
347		if (!strncmp(buf, "serial", 6)) {
348			buf += 6;
349			early_serial_init(buf);
350			early_console_register(&early_serial_console, keep);
351			if (!strncmp(buf, ",ttyS", 5))
352				buf += 5;
353		}
354		if (!strncmp(buf, "ttyS", 4)) {
355			early_serial_init(buf + 4);
356			early_console_register(&early_serial_console, keep);
357		}
358#ifdef CONFIG_PCI
359		if (!strncmp(buf, "pciserial", 9)) {
360			early_pci_serial_init(buf + 9);
361			early_console_register(&early_serial_console, keep);
362			buf += 9; /* Keep from match the above "serial" */
363		}
364#endif
365		if (!strncmp(buf, "vga", 3) &&
366		    boot_params.screen_info.orig_video_isVGA == 1) {
367			max_xpos = boot_params.screen_info.orig_video_cols;
368			max_ypos = boot_params.screen_info.orig_video_lines;
369			current_ypos = boot_params.screen_info.orig_y;
370			early_console_register(&early_vga_console, keep);
371		}
372#ifdef CONFIG_EARLY_PRINTK_DBGP
373		if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
374			early_console_register(&early_dbgp_console, keep);
375#endif
376#ifdef CONFIG_HVC_XEN
377		if (!strncmp(buf, "xen", 3))
378			early_console_register(&xenboot_console, keep);
379#endif
380#ifdef CONFIG_EARLY_PRINTK_EFI
381		if (!strncmp(buf, "efi", 3))
382			early_console_register(&early_efi_console, keep);
383#endif
384
385		buf++;
386	}
387	return 0;
388}
389
390early_param("earlyprintk", setup_early_printk);