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