Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux-2.6] / arch / x86 / kernel / early_printk.c
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 <asm/io.h>
7 #include <asm/processor.h>
8 #include <asm/fcntl.h>
9 #include <asm/setup.h>
10 #include <xen/hvc-console.h>
11
12 /* Simple VGA output */
13 #define VGABASE         (__ISA_IO_base + 0xb8000)
14
15 static int max_ypos = 25, max_xpos = 80;
16 static int current_ypos = 25, current_xpos = 0;
17
18 static void early_vga_write(struct console *con, const char *str, unsigned n)
19 {
20         char c;
21         int  i, k, j;
22
23         while ((c = *str++) != '\0' && n-- > 0) {
24                 if (current_ypos >= max_ypos) {
25                         /* scroll 1 line up */
26                         for (k = 1, j = 0; k < max_ypos; k++, j++) {
27                                 for (i = 0; i < max_xpos; i++) {
28                                         writew(readw(VGABASE+2*(max_xpos*k+i)),
29                                                VGABASE + 2*(max_xpos*j + i));
30                                 }
31                         }
32                         for (i = 0; i < max_xpos; i++)
33                                 writew(0x720, VGABASE + 2*(max_xpos*j + i));
34                         current_ypos = max_ypos-1;
35                 }
36                 if (c == '\n') {
37                         current_xpos = 0;
38                         current_ypos++;
39                 } else if (c != '\r')  {
40                         writew(((0x7 << 8) | (unsigned short) c),
41                                VGABASE + 2*(max_xpos*current_ypos +
42                                                 current_xpos++));
43                         if (current_xpos >= max_xpos) {
44                                 current_xpos = 0;
45                                 current_ypos++;
46                         }
47                 }
48         }
49 }
50
51 static struct console early_vga_console = {
52         .name =         "earlyvga",
53         .write =        early_vga_write,
54         .flags =        CON_PRINTBUFFER,
55         .index =        -1,
56 };
57
58 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
59
60 static int early_serial_base = 0x3f8;  /* ttyS0 */
61
62 #define XMTRDY          0x20
63
64 #define DLAB            0x80
65
66 #define TXR             0       /*  Transmit register (WRITE) */
67 #define RXR             0       /*  Receive register  (READ)  */
68 #define IER             1       /*  Interrupt Enable          */
69 #define IIR             2       /*  Interrupt ID              */
70 #define FCR             2       /*  FIFO control              */
71 #define LCR             3       /*  Line control              */
72 #define MCR             4       /*  Modem control             */
73 #define LSR             5       /*  Line Status               */
74 #define MSR             6       /*  Modem Status              */
75 #define DLL             0       /*  Divisor Latch Low         */
76 #define DLH             1       /*  Divisor latch High        */
77
78 static int early_serial_putc(unsigned char ch)
79 {
80         unsigned timeout = 0xffff;
81         while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
82                 cpu_relax();
83         outb(ch, early_serial_base + TXR);
84         return timeout ? 0 : -1;
85 }
86
87 static void early_serial_write(struct console *con, const char *s, unsigned n)
88 {
89         while (*s && n-- > 0) {
90                 if (*s == '\n')
91                         early_serial_putc('\r');
92                 early_serial_putc(*s);
93                 s++;
94         }
95 }
96
97 #define DEFAULT_BAUD 9600
98
99 static __init void early_serial_init(char *s)
100 {
101         unsigned char c;
102         unsigned divisor;
103         unsigned baud = DEFAULT_BAUD;
104         char *e;
105
106         if (*s == ',')
107                 ++s;
108
109         if (*s) {
110                 unsigned port;
111                 if (!strncmp(s,"0x",2)) {
112                         early_serial_base = simple_strtoul(s, &e, 16);
113                 } else {
114                         static int bases[] = { 0x3f8, 0x2f8 };
115
116                         if (!strncmp(s,"ttyS",4))
117                                 s += 4;
118                         port = simple_strtoul(s, &e, 10);
119                         if (port > 1 || s == e)
120                                 port = 0;
121                         early_serial_base = bases[port];
122                 }
123                 s += strcspn(s, ",");
124                 if (*s == ',')
125                         s++;
126         }
127
128         outb(0x3, early_serial_base + LCR);     /* 8n1 */
129         outb(0, early_serial_base + IER);       /* no interrupt */
130         outb(0, early_serial_base + FCR);       /* no fifo */
131         outb(0x3, early_serial_base + MCR);     /* DTR + RTS */
132
133         if (*s) {
134                 baud = simple_strtoul(s, &e, 0);
135                 if (baud == 0 || s == e)
136                         baud = DEFAULT_BAUD;
137         }
138
139         divisor = 115200 / baud;
140         c = inb(early_serial_base + LCR);
141         outb(c | DLAB, early_serial_base + LCR);
142         outb(divisor & 0xff, early_serial_base + DLL);
143         outb((divisor >> 8) & 0xff, early_serial_base + DLH);
144         outb(c & ~DLAB, early_serial_base + LCR);
145 }
146
147 static struct console early_serial_console = {
148         .name =         "earlyser",
149         .write =        early_serial_write,
150         .flags =        CON_PRINTBUFFER,
151         .index =        -1,
152 };
153
154 /* Console interface to a host file on AMD's SimNow! */
155
156 static int simnow_fd;
157
158 enum {
159         MAGIC1 = 0xBACCD00A,
160         MAGIC2 = 0xCA110000,
161         XOPEN = 5,
162         XWRITE = 4,
163 };
164
165 static noinline long simnow(long cmd, long a, long b, long c)
166 {
167         long ret;
168         asm volatile("cpuid" :
169                      "=a" (ret) :
170                      "b" (a), "c" (b), "d" (c), "0" (MAGIC1), "D" (cmd + MAGIC2));
171         return ret;
172 }
173
174 static void __init simnow_init(char *str)
175 {
176         char *fn = "klog";
177         if (*str == '=')
178                 fn = ++str;
179         /* error ignored */
180         simnow_fd = simnow(XOPEN, (unsigned long)fn, O_WRONLY|O_APPEND|O_CREAT, 0644);
181 }
182
183 static void simnow_write(struct console *con, const char *s, unsigned n)
184 {
185         simnow(XWRITE, simnow_fd, (unsigned long)s, n);
186 }
187
188 static struct console simnow_console = {
189         .name =         "simnow",
190         .write =        simnow_write,
191         .flags =        CON_PRINTBUFFER,
192         .index =        -1,
193 };
194
195 /* Direct interface for emergencies */
196 static struct console *early_console = &early_vga_console;
197 static int early_console_initialized = 0;
198
199 void early_printk(const char *fmt, ...)
200 {
201         char buf[512];
202         int n;
203         va_list ap;
204
205         va_start(ap,fmt);
206         n = vscnprintf(buf,512,fmt,ap);
207         early_console->write(early_console,buf,n);
208         va_end(ap);
209 }
210
211 static int __initdata keep_early;
212
213 static int __init setup_early_printk(char *buf)
214 {
215         if (!buf)
216                 return 0;
217
218         if (early_console_initialized)
219                 return 0;
220         early_console_initialized = 1;
221
222         if (strstr(buf, "keep"))
223                 keep_early = 1;
224
225         if (!strncmp(buf, "serial", 6)) {
226                 early_serial_init(buf + 6);
227                 early_console = &early_serial_console;
228         } else if (!strncmp(buf, "ttyS", 4)) {
229                 early_serial_init(buf);
230                 early_console = &early_serial_console;
231         } else if (!strncmp(buf, "vga", 3)
232                    && boot_params.screen_info.orig_video_isVGA == 1) {
233                 max_xpos = boot_params.screen_info.orig_video_cols;
234                 max_ypos = boot_params.screen_info.orig_video_lines;
235                 current_ypos = boot_params.screen_info.orig_y;
236                 early_console = &early_vga_console;
237         } else if (!strncmp(buf, "simnow", 6)) {
238                 simnow_init(buf + 6);
239                 early_console = &simnow_console;
240                 keep_early = 1;
241 #ifdef CONFIG_HVC_XEN
242         } else if (!strncmp(buf, "xen", 3)) {
243                 early_console = &xenboot_console;
244 #endif
245         }
246
247         if (keep_early)
248                 early_console->flags &= ~CON_BOOT;
249         else
250                 early_console->flags |= CON_BOOT;
251         register_console(early_console);
252         return 0;
253 }
254 early_param("earlyprintk", setup_early_printk);