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
13#define VGABASE (__ISA_IO_base + 0xb8000)
14
15static int max_ypos = 25, max_xpos = 80;
16static int current_ypos = 25, current_xpos = 0;
17
18static 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
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
51static struct console early_vga_console = {
52 .name = "earlyvga",
53 .write = early_vga_write,
54 .flags = CON_PRINTBUFFER,
55 .index = -1,
56};
57
58
59
60static int early_serial_base = 0x3f8;
61
62#define XMTRDY 0x20
63
64#define DLAB 0x80
65
66#define TXR 0
67#define RXR 0
68#define IER 1
69#define IIR 2
70#define FCR 2
71#define LCR 3
72#define MCR 4
73#define LSR 5
74#define MSR 6
75#define DLL 0
76#define DLH 1
77
78static 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
87static 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
99static __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);
129 outb(0, early_serial_base + IER);
130 outb(0, early_serial_base + FCR);
131 outb(0x3, early_serial_base + MCR);
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
147static struct console early_serial_console = {
148 .name = "earlyser",
149 .write = early_serial_write,
150 .flags = CON_PRINTBUFFER,
151 .index = -1,
152};
153
154
155
156static int simnow_fd;
157
158enum {
159 MAGIC1 = 0xBACCD00A,
160 MAGIC2 = 0xCA110000,
161 XOPEN = 5,
162 XWRITE = 4,
163};
164
165static 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
174static void __init simnow_init(char *str)
175{
176 char *fn = "klog";
177 if (*str == '=')
178 fn = ++str;
179
180 simnow_fd = simnow(XOPEN, (unsigned long)fn, O_WRONLY|O_APPEND|O_CREAT, 0644);
181}
182
183static void simnow_write(struct console *con, const char *s, unsigned n)
184{
185 simnow(XWRITE, simnow_fd, (unsigned long)s, n);
186}
187
188static struct console simnow_console = {
189 .name = "simnow",
190 .write = simnow_write,
191 .flags = CON_PRINTBUFFER,
192 .index = -1,
193};
194
195
196struct console *early_console = &early_vga_console;
197static int early_console_initialized = 0;
198
199void 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
211static int __initdata keep_early;
212
213static 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}
254early_param("earlyprintk", setup_early_printk);
255
