xref: /linux/arch/x86/kernel/early_printk.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
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 
27 static int max_ypos = 25, max_xpos = 80;
28 static int current_ypos = 25, current_xpos;
29 
30 static 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 
71 static 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 
80 static 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 
98 static void mem32_serial_out(unsigned long addr, int offset, int value)
99 {
100 	uint32_t *vaddr = (uint32_t *)addr;
101 	/* shift implied by pointer type */
102 	writel(value, vaddr + offset);
103 }
104 
105 static unsigned int mem32_serial_in(unsigned long addr, int offset)
106 {
107 	uint32_t *vaddr = (uint32_t *)addr;
108 	/* shift implied by pointer type */
109 	return readl(vaddr + offset);
110 }
111 
112 static unsigned int io_serial_in(unsigned long addr, int offset)
113 {
114 	return inb(addr + offset);
115 }
116 
117 static void io_serial_out(unsigned long addr, int offset, int value)
118 {
119 	outb(value, addr + offset);
120 }
121 
122 static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
123 static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
124 
125 static int early_serial_putc(unsigned char ch)
126 {
127 	unsigned timeout = 0xffff;
128 
129 	while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
130 		cpu_relax();
131 	serial_out(early_serial_base, TXR, ch);
132 	return timeout ? 0 : -1;
133 }
134 
135 static void early_serial_write(struct console *con, const char *s, unsigned n)
136 {
137 	while (*s && n-- > 0) {
138 		if (*s == '\n')
139 			early_serial_putc('\r');
140 		early_serial_putc(*s);
141 		s++;
142 	}
143 }
144 
145 static __init void early_serial_hw_init(unsigned divisor)
146 {
147 	unsigned char c;
148 
149 	serial_out(early_serial_base, LCR, 0x3);	/* 8n1 */
150 	serial_out(early_serial_base, IER, 0);	/* no interrupt */
151 	serial_out(early_serial_base, FCR, 0);	/* no fifo */
152 	serial_out(early_serial_base, MCR, 0x3);	/* DTR + RTS */
153 
154 	c = serial_in(early_serial_base, LCR);
155 	serial_out(early_serial_base, LCR, c | DLAB);
156 	serial_out(early_serial_base, DLL, divisor & 0xff);
157 	serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
158 	serial_out(early_serial_base, LCR, c & ~DLAB);
159 }
160 
161 #define DEFAULT_BAUD 9600
162 
163 static __init void early_serial_init(char *s)
164 {
165 	unsigned divisor;
166 	unsigned long baud = DEFAULT_BAUD;
167 	char *e;
168 
169 	if (*s == ',')
170 		++s;
171 
172 	if (*s) {
173 		unsigned port;
174 		if (!strncmp(s, "0x", 2)) {
175 			early_serial_base = simple_strtoul(s, &e, 16);
176 		} else {
177 			static const int __initconst bases[] = { 0x3f8, 0x2f8 };
178 
179 			if (!strncmp(s, "ttyS", 4))
180 				s += 4;
181 			port = simple_strtoul(s, &e, 10);
182 			if (port > 1 || s == e)
183 				port = 0;
184 			early_serial_base = bases[port];
185 		}
186 		s += strcspn(s, ",");
187 		if (*s == ',')
188 			s++;
189 	}
190 
191 	if (*s) {
192 		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
193 			baud = DEFAULT_BAUD;
194 	}
195 
196 	/* Convert from baud to divisor value */
197 	divisor = 115200 / baud;
198 
199 	/* These will always be IO based ports */
200 	serial_in = io_serial_in;
201 	serial_out = io_serial_out;
202 
203 	/* Set up the HW */
204 	early_serial_hw_init(divisor);
205 }
206 
207 #ifdef CONFIG_PCI
208 /*
209  * early_pci_serial_init()
210  *
211  * This function is invoked when the early_printk param starts with "pciserial"
212  * The rest of the param should be ",B:D.F,baud" where B, D & F describe the
213  * location of a PCI device that must be a UART device.
214  */
215 static __init void early_pci_serial_init(char *s)
216 {
217 	unsigned divisor;
218 	unsigned long baud = DEFAULT_BAUD;
219 	u8 bus, slot, func;
220 	uint32_t classcode, bar0;
221 	uint16_t cmdreg;
222 	char *e;
223 
224 
225 	/*
226 	 * First, part the param to get the BDF values
227 	 */
228 	if (*s == ',')
229 		++s;
230 
231 	if (*s == 0)
232 		return;
233 
234 	bus = (u8)simple_strtoul(s, &e, 16);
235 	s = e;
236 	if (*s != ':')
237 		return;
238 	++s;
239 	slot = (u8)simple_strtoul(s, &e, 16);
240 	s = e;
241 	if (*s != '.')
242 		return;
243 	++s;
244 	func = (u8)simple_strtoul(s, &e, 16);
245 	s = e;
246 
247 	/* A baud might be following */
248 	if (*s == ',')
249 		s++;
250 
251 	/*
252 	 * Second, find the device from the BDF
253 	 */
254 	cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
255 	classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
256 	bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
257 
258 	/*
259 	 * Verify it is a UART type device
260 	 */
261 	if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
262 	     (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
263 	   (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */
264 		return;
265 
266 	/*
267 	 * Determine if it is IO or memory mapped
268 	 */
269 	if (bar0 & 0x01) {
270 		/* it is IO mapped */
271 		serial_in = io_serial_in;
272 		serial_out = io_serial_out;
273 		early_serial_base = bar0&0xfffffffc;
274 		write_pci_config(bus, slot, func, PCI_COMMAND,
275 						cmdreg|PCI_COMMAND_IO);
276 	} else {
277 		/* It is memory mapped - assume 32-bit alignment */
278 		serial_in = mem32_serial_in;
279 		serial_out = mem32_serial_out;
280 		/* WARNING! assuming the address is always in the first 4G */
281 		early_serial_base =
282 			(unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
283 		write_pci_config(bus, slot, func, PCI_COMMAND,
284 						cmdreg|PCI_COMMAND_MEMORY);
285 	}
286 
287 	/*
288 	 * Lastly, initalize the hardware
289 	 */
290 	if (*s) {
291 		if (strcmp(s, "nocfg") == 0)
292 			/* Sometimes, we want to leave the UART alone
293 			 * and assume the BIOS has set it up correctly.
294 			 * "nocfg" tells us this is the case, and we
295 			 * should do no more setup.
296 			 */
297 			return;
298 		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
299 			baud = DEFAULT_BAUD;
300 	}
301 
302 	/* Convert from baud to divisor value */
303 	divisor = 115200 / baud;
304 
305 	/* Set up the HW */
306 	early_serial_hw_init(divisor);
307 }
308 #endif
309 
310 static struct console early_serial_console = {
311 	.name =		"earlyser",
312 	.write =	early_serial_write,
313 	.flags =	CON_PRINTBUFFER,
314 	.index =	-1,
315 };
316 
317 static inline void early_console_register(struct console *con, int keep_early)
318 {
319 	if (con->index != -1) {
320 		printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
321 		       con->name);
322 		return;
323 	}
324 	early_console = con;
325 	if (keep_early)
326 		early_console->flags &= ~CON_BOOT;
327 	else
328 		early_console->flags |= CON_BOOT;
329 	register_console(early_console);
330 }
331 
332 static int __init setup_early_printk(char *buf)
333 {
334 	int keep;
335 
336 	if (!buf)
337 		return 0;
338 
339 	if (early_console)
340 		return 0;
341 
342 	keep = (strstr(buf, "keep") != NULL);
343 
344 	while (*buf != '\0') {
345 		if (!strncmp(buf, "serial", 6)) {
346 			buf += 6;
347 			early_serial_init(buf);
348 			early_console_register(&early_serial_console, keep);
349 			if (!strncmp(buf, ",ttyS", 5))
350 				buf += 5;
351 		}
352 		if (!strncmp(buf, "ttyS", 4)) {
353 			early_serial_init(buf + 4);
354 			early_console_register(&early_serial_console, keep);
355 		}
356 #ifdef CONFIG_PCI
357 		if (!strncmp(buf, "pciserial", 9)) {
358 			early_pci_serial_init(buf + 9);
359 			early_console_register(&early_serial_console, keep);
360 			buf += 9; /* Keep from match the above "serial" */
361 		}
362 #endif
363 		if (!strncmp(buf, "vga", 3) &&
364 		    boot_params.screen_info.orig_video_isVGA == 1) {
365 			max_xpos = boot_params.screen_info.orig_video_cols;
366 			max_ypos = boot_params.screen_info.orig_video_lines;
367 			current_ypos = boot_params.screen_info.orig_y;
368 			early_console_register(&early_vga_console, keep);
369 		}
370 #ifdef CONFIG_EARLY_PRINTK_DBGP
371 		if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
372 			early_console_register(&early_dbgp_console, keep);
373 #endif
374 #ifdef CONFIG_HVC_XEN
375 		if (!strncmp(buf, "xen", 3))
376 			early_console_register(&xenboot_console, keep);
377 #endif
378 #ifdef CONFIG_EARLY_PRINTK_INTEL_MID
379 		if (!strncmp(buf, "hsu", 3)) {
380 			hsu_early_console_init(buf + 3);
381 			early_console_register(&early_hsu_console, keep);
382 		}
383 #endif
384 #ifdef CONFIG_EARLY_PRINTK_EFI
385 		if (!strncmp(buf, "efi", 3))
386 			early_console_register(&early_efi_console, keep);
387 #endif
388 
389 		buf++;
390 	}
391 	return 0;
392 }
393 
394 early_param("earlyprintk", setup_early_printk);
395