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v5.4
  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 <asm/io.h>
 12#include <asm/processor.h>
 13#include <asm/fcntl.h>
 14#include <asm/setup.h>
 15#include <xen/hvc-console.h>
 16#include <asm/pci-direct.h>
 17#include <asm/fixmap.h>
 18#include <asm/intel-mid.h>
 19#include <asm/pgtable.h>
 20#include <linux/usb/ehci_def.h>
 21#include <linux/usb/xhci-dbgp.h>
 22#include <linux/efi.h>
 23#include <asm/efi.h>
 24#include <asm/pci_x86.h>
 25
 26/* Simple VGA output */
 27#define VGABASE		(__ISA_IO_base + 0xb8000)
 28
 29static int max_ypos = 25, max_xpos = 80;
 30static int current_ypos = 25, current_xpos;
 31
 32static void early_vga_write(struct console *con, const char *str, unsigned n)
 33{
 34	char c;
 35	int  i, k, j;
 36
 37	while ((c = *str++) != '\0' && n-- > 0) {
 38		if (current_ypos >= max_ypos) {
 39			/* scroll 1 line up */
 40			for (k = 1, j = 0; k < max_ypos; k++, j++) {
 41				for (i = 0; i < max_xpos; i++) {
 42					writew(readw(VGABASE+2*(max_xpos*k+i)),
 43					       VGABASE + 2*(max_xpos*j + i));
 44				}
 45			}
 46			for (i = 0; i < max_xpos; i++)
 47				writew(0x720, VGABASE + 2*(max_xpos*j + i));
 48			current_ypos = max_ypos-1;
 49		}
 50#ifdef CONFIG_KGDB_KDB
 51		if (c == '\b') {
 52			if (current_xpos > 0)
 53				current_xpos--;
 54		} else if (c == '\r') {
 55			current_xpos = 0;
 56		} else
 57#endif
 58		if (c == '\n') {
 59			current_xpos = 0;
 60			current_ypos++;
 61		} else if (c != '\r')  {
 62			writew(((0x7 << 8) | (unsigned short) c),
 63			       VGABASE + 2*(max_xpos*current_ypos +
 64						current_xpos++));
 65			if (current_xpos >= max_xpos) {
 66				current_xpos = 0;
 67				current_ypos++;
 68			}
 69		}
 70	}
 71}
 72
 73static struct console early_vga_console = {
 74	.name =		"earlyvga",
 75	.write =	early_vga_write,
 76	.flags =	CON_PRINTBUFFER,
 77	.index =	-1,
 78};
 79
 80/* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
 81
 82static unsigned long early_serial_base = 0x3f8;  /* ttyS0 */
 83
 84#define XMTRDY          0x20
 85
 86#define DLAB		0x80
 87
 88#define TXR             0       /*  Transmit register (WRITE) */
 89#define RXR             0       /*  Receive register  (READ)  */
 90#define IER             1       /*  Interrupt Enable          */
 91#define IIR             2       /*  Interrupt ID              */
 92#define FCR             2       /*  FIFO control              */
 93#define LCR             3       /*  Line control              */
 94#define MCR             4       /*  Modem control             */
 95#define LSR             5       /*  Line Status               */
 96#define MSR             6       /*  Modem Status              */
 97#define DLL             0       /*  Divisor Latch Low         */
 98#define DLH             1       /*  Divisor latch High        */
 99
100static unsigned int io_serial_in(unsigned long addr, int offset)
101{
102	return inb(addr + offset);
103}
104
105static void io_serial_out(unsigned long addr, int offset, int value)
106{
107	outb(value, addr + offset);
108}
109
110static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
111static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
112
113static int early_serial_putc(unsigned char ch)
114{
115	unsigned timeout = 0xffff;
116
117	while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
118		cpu_relax();
119	serial_out(early_serial_base, TXR, ch);
120	return timeout ? 0 : -1;
121}
122
123static void early_serial_write(struct console *con, const char *s, unsigned n)
124{
125	while (*s && n-- > 0) {
126		if (*s == '\n')
127			early_serial_putc('\r');
128		early_serial_putc(*s);
129		s++;
130	}
131}
132
133static __init void early_serial_hw_init(unsigned divisor)
134{
135	unsigned char c;
136
137	serial_out(early_serial_base, LCR, 0x3);	/* 8n1 */
138	serial_out(early_serial_base, IER, 0);	/* no interrupt */
139	serial_out(early_serial_base, FCR, 0);	/* no fifo */
140	serial_out(early_serial_base, MCR, 0x3);	/* DTR + RTS */
141
142	c = serial_in(early_serial_base, LCR);
143	serial_out(early_serial_base, LCR, c | DLAB);
144	serial_out(early_serial_base, DLL, divisor & 0xff);
145	serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
146	serial_out(early_serial_base, LCR, c & ~DLAB);
147}
148
149#define DEFAULT_BAUD 9600
150
151static __init void early_serial_init(char *s)
152{
153	unsigned divisor;
154	unsigned long baud = DEFAULT_BAUD;
155	char *e;
156
157	if (*s == ',')
158		++s;
159
160	if (*s) {
161		unsigned port;
162		if (!strncmp(s, "0x", 2)) {
163			early_serial_base = simple_strtoul(s, &e, 16);
164		} else {
165			static const int __initconst bases[] = { 0x3f8, 0x2f8 };
166
167			if (!strncmp(s, "ttyS", 4))
168				s += 4;
169			port = simple_strtoul(s, &e, 10);
170			if (port > 1 || s == e)
171				port = 0;
172			early_serial_base = bases[port];
173		}
174		s += strcspn(s, ",");
175		if (*s == ',')
176			s++;
177	}
178
179	if (*s) {
180		baud = simple_strtoull(s, &e, 0);
181
182		if (baud == 0 || s == e)
183			baud = DEFAULT_BAUD;
184	}
185
186	/* Convert from baud to divisor value */
187	divisor = 115200 / baud;
188
189	/* These will always be IO based ports */
190	serial_in = io_serial_in;
191	serial_out = io_serial_out;
192
193	/* Set up the HW */
194	early_serial_hw_init(divisor);
195}
196
197#ifdef CONFIG_PCI
198static void mem32_serial_out(unsigned long addr, int offset, int value)
199{
200	u32 __iomem *vaddr = (u32 __iomem *)addr;
201	/* shift implied by pointer type */
202	writel(value, vaddr + offset);
203}
204
205static unsigned int mem32_serial_in(unsigned long addr, int offset)
206{
207	u32 __iomem *vaddr = (u32 __iomem *)addr;
208	/* shift implied by pointer type */
209	return readl(vaddr + offset);
210}
211
212/*
213 * early_pci_serial_init()
214 *
215 * This function is invoked when the early_printk param starts with "pciserial"
216 * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe
217 * the location of a PCI device that must be a UART device. "force" is optional
218 * and overrides the use of an UART device with a wrong PCI class code.
219 */
220static __init void early_pci_serial_init(char *s)
221{
222	unsigned divisor;
223	unsigned long baud = DEFAULT_BAUD;
224	u8 bus, slot, func;
225	u32 classcode, bar0;
226	u16 cmdreg;
227	char *e;
228	int force = 0;
229
 
 
 
 
230	if (*s == ',')
231		++s;
232
233	if (*s == 0)
234		return;
235
236	/* Force the use of an UART device with wrong class code */
237	if (!strncmp(s, "force,", 6)) {
238		force = 1;
239		s += 6;
240	}
241
242	/*
243	 * Part the param to get the BDF values
244	 */
245	bus = (u8)simple_strtoul(s, &e, 16);
246	s = e;
247	if (*s != ':')
248		return;
249	++s;
250	slot = (u8)simple_strtoul(s, &e, 16);
251	s = e;
252	if (*s != '.')
253		return;
254	++s;
255	func = (u8)simple_strtoul(s, &e, 16);
256	s = e;
257
258	/* A baud might be following */
259	if (*s == ',')
260		s++;
261
262	/*
263	 * Find the device from the BDF
264	 */
265	cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
266	classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
267	bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
268
269	/*
270	 * Verify it is a UART type device
271	 */
272	if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
273	     (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
274	   (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
275		if (!force)
276			return;
277	}
278
279	/*
280	 * Determine if it is IO or memory mapped
281	 */
282	if (bar0 & 0x01) {
283		/* it is IO mapped */
284		serial_in = io_serial_in;
285		serial_out = io_serial_out;
286		early_serial_base = bar0&0xfffffffc;
287		write_pci_config(bus, slot, func, PCI_COMMAND,
288						cmdreg|PCI_COMMAND_IO);
289	} else {
290		/* It is memory mapped - assume 32-bit alignment */
291		serial_in = mem32_serial_in;
292		serial_out = mem32_serial_out;
293		/* WARNING! assuming the address is always in the first 4G */
294		early_serial_base =
295			(unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
296		write_pci_config(bus, slot, func, PCI_COMMAND,
297						cmdreg|PCI_COMMAND_MEMORY);
298	}
299
300	/*
301	 * Initialize the hardware
302	 */
303	if (*s) {
304		if (strcmp(s, "nocfg") == 0)
305			/* Sometimes, we want to leave the UART alone
306			 * and assume the BIOS has set it up correctly.
307			 * "nocfg" tells us this is the case, and we
308			 * should do no more setup.
309			 */
310			return;
311		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
312			baud = DEFAULT_BAUD;
313	}
314
315	/* Convert from baud to divisor value */
316	divisor = 115200 / baud;
317
318	/* Set up the HW */
319	early_serial_hw_init(divisor);
320}
321#endif
322
323static struct console early_serial_console = {
324	.name =		"earlyser",
325	.write =	early_serial_write,
326	.flags =	CON_PRINTBUFFER,
327	.index =	-1,
328};
329
330static void early_console_register(struct console *con, int keep_early)
331{
332	if (con->index != -1) {
333		printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
334		       con->name);
335		return;
336	}
337	early_console = con;
338	if (keep_early)
339		early_console->flags &= ~CON_BOOT;
340	else
341		early_console->flags |= CON_BOOT;
342	register_console(early_console);
343}
344
345static int __init setup_early_printk(char *buf)
346{
347	int keep;
348
349	if (!buf)
350		return 0;
351
352	if (early_console)
353		return 0;
354
355	keep = (strstr(buf, "keep") != NULL);
356
357	while (*buf != '\0') {
358		if (!strncmp(buf, "serial", 6)) {
359			buf += 6;
360			early_serial_init(buf);
361			early_console_register(&early_serial_console, keep);
362			if (!strncmp(buf, ",ttyS", 5))
363				buf += 5;
364		}
365		if (!strncmp(buf, "ttyS", 4)) {
366			early_serial_init(buf + 4);
367			early_console_register(&early_serial_console, keep);
368		}
369#ifdef CONFIG_PCI
370		if (!strncmp(buf, "pciserial", 9)) {
371			early_pci_serial_init(buf + 9);
372			early_console_register(&early_serial_console, keep);
373			buf += 9; /* Keep from match the above "serial" */
374		}
375#endif
376		if (!strncmp(buf, "vga", 3) &&
377		    boot_params.screen_info.orig_video_isVGA == 1) {
378			max_xpos = boot_params.screen_info.orig_video_cols;
379			max_ypos = boot_params.screen_info.orig_video_lines;
380			current_ypos = boot_params.screen_info.orig_y;
381			early_console_register(&early_vga_console, keep);
382		}
383#ifdef CONFIG_EARLY_PRINTK_DBGP
384		if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
385			early_console_register(&early_dbgp_console, keep);
386#endif
387#ifdef CONFIG_HVC_XEN
388		if (!strncmp(buf, "xen", 3))
389			early_console_register(&xenboot_console, keep);
390#endif
391#ifdef CONFIG_EARLY_PRINTK_USB_XDBC
392		if (!strncmp(buf, "xdbc", 4))
393			early_xdbc_parse_parameter(buf + 4);
394#endif
395
396		buf++;
397	}
398	return 0;
399}
400
401early_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);