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/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
  23 /* Simple VGA output */
  24 #define VGABASE         (__ISA_IO_base + 0xb8000)
  25
  26 static int max_ypos = 25, max_xpos = 80;
  27 static int current_ypos = 25, current_xpos;
  28
  29 static void early_vga_write(struct console *con, const char *str, unsigned n)
  30 {
  31         char c;
  32         int  i, k, j;
  33
  34         while ((c = *str++) != '\0' && n-- > 0) {
  35                 if (current_ypos >= max_ypos) {
  36                         /* scroll 1 line up */
  37                         for (k = 1, j = 0; k < max_ypos; k++, j++) {
  38                                 for (i = 0; i < max_xpos; i++) {
  39                                         writew(readw(VGABASE+2*(max_xpos*k+i)),
  40                                                VGABASE + 2*(max_xpos*j + i));
  41                                 }
  42                         }
  43                         for (i = 0; i < max_xpos; i++)
  44                                 writew(0x720, VGABASE + 2*(max_xpos*j + i));
  45                         current_ypos = max_ypos-1;
  46                 }
  47 #ifdef CONFIG_KGDB_KDB
  48                 if (c == '\b') {
  49                         if (current_xpos > 0)
  50                                 current_xpos--;
  51                 } else if (c == '\r') {
  52                         current_xpos = 0;
  53                 } else
  54 #endif
  55                 if (c == '\n') {
  56                         current_xpos = 0;
  57                         current_ypos++;
  58                 } else if (c != '\r')  {
  59                         writew(((0x7 << 8) | (unsigned short) c),
  60                                VGABASE + 2*(max_xpos*current_ypos +
  61                                                 current_xpos++));
  62                         if (current_xpos >= max_xpos) {
  63                                 current_xpos = 0;
  64                                 current_ypos++;
  65                         }
  66                 }
  67         }
  68 }
  69
  70 static struct console early_vga_console = {
  71         .name =         "earlyvga",
  72         .write =        early_vga_write,
  73         .flags =        CON_PRINTBUFFER,
  74         .index =        -1,
  75 };
  76
  77 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
  78
  79 static int early_serial_base = 0x3f8;  /* ttyS0 */
  80
  81 #define XMTRDY          0x20
  82
  83 #define DLAB            0x80
  84
  85 #define TXR             0       /*  Transmit register (WRITE) */
  86 #define RXR             0       /*  Receive register  (READ)  */
  87 #define IER             1       /*  Interrupt Enable          */
  88 #define IIR             2       /*  Interrupt ID              */
  89 #define FCR             2       /*  FIFO control              */
  90 #define LCR             3       /*  Line control              */
  91 #define MCR             4       /*  Modem control             */
  92 #define LSR             5       /*  Line Status               */
  93 #define MSR             6       /*  Modem Status              */
  94 #define DLL             0       /*  Divisor Latch Low         */
  95 #define DLH             1       /*  Divisor latch High        */
  96
  97 static int early_serial_putc(unsigned char ch)
  98 {
  99         unsigned timeout = 0xffff;
 100
 101         while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
 102                 cpu_relax();
 103         outb(ch, early_serial_base + TXR);
 104         return timeout ? 0 : -1;
 105 }
 106
 107 static void early_serial_write(struct console *con, const char *s, unsigned n)
 108 {
 109         while (*s && n-- > 0) {
 110                 if (*s == '\n')
 111                         early_serial_putc('\r');
 112                 early_serial_putc(*s);
 113                 s++;
 114         }
 115 }
 116
 117 #define DEFAULT_BAUD 9600
 118
 119 static __init void early_serial_init(char *s)
 120 {
 121         unsigned char c;
 122         unsigned divisor;
 123         unsigned baud = DEFAULT_BAUD;
 124         char *e;
 125
 126         if (*s == ',')
 127                 ++s;
 128
 129         if (*s) {
 130                 unsigned port;
 131                 if (!strncmp(s, "0x", 2)) {
 132                         early_serial_base = simple_strtoul(s, &e, 16);
 133                 } else {
 134                         static const int __initconst bases[] = { 0x3f8, 0x2f8 };
 135
 136                         if (!strncmp(s, "ttyS", 4))
 137                                 s += 4;
 138                         port = simple_strtoul(s, &e, 10);
 139                         if (port > 1 || s == e)
 140                                 port = 0;
 141                         early_serial_base = bases[port];
 142                 }
 143                 s += strcspn(s, ",");
 144                 if (*s == ',')
 145                         s++;
 146         }
 147
 148         outb(0x3, early_serial_base + LCR);     /* 8n1 */
 149         outb(0, early_serial_base + IER);       /* no interrupt */
 150         outb(0, early_serial_base + FCR);       /* no fifo */
 151         outb(0x3, early_serial_base + MCR);     /* DTR + RTS */
 152
 153         if (*s) {
 154                 baud = simple_strtoul(s, &e, 0);
 155                 if (baud == 0 || s == e)
 156                         baud = DEFAULT_BAUD;
 157         }
 158
 159         divisor = 115200 / baud;
 160         c = inb(early_serial_base + LCR);
 161         outb(c | DLAB, early_serial_base + LCR);
 162         outb(divisor & 0xff, early_serial_base + DLL);
 163         outb((divisor >> 8) & 0xff, early_serial_base + DLH);
 164         outb(c & ~DLAB, early_serial_base + LCR);
 165 }
 166
 167 static struct console early_serial_console = {
 168         .name =         "earlyser",
 169         .write =        early_serial_write,
 170         .flags =        CON_PRINTBUFFER,
 171         .index =        -1,
 172 };
 173
 174 static inline void early_console_register(struct console *con, int keep_early)
 175 {
 176         if (con->index != -1) {
 177                 printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
 178                        con->name);
 179                 return;
 180         }
 181         early_console = con;
 182         if (keep_early)
 183                 early_console->flags &= ~CON_BOOT;
 184         else
 185                 early_console->flags |= CON_BOOT;
 186         register_console(early_console);
 187 }
 188
 189 static int __init setup_early_printk(char *buf)
 190 {
 191         int keep;
 192
 193         if (!buf)
 194                 return 0;
 195
 196         if (early_console)
 197                 return 0;
 198
 199         keep = (strstr(buf, "keep") != NULL);
 200
 201         while (*buf != '\0') {
 202                 if (!strncmp(buf, "serial", 6)) {
 203                         buf += 6;
 204                         early_serial_init(buf);
 205                         early_console_register(&early_serial_console, keep);
 206                         if (!strncmp(buf, ",ttyS", 5))
 207                                 buf += 5;
 208                 }
 209                 if (!strncmp(buf, "ttyS", 4)) {
 210                         early_serial_init(buf + 4);
 211                         early_console_register(&early_serial_console, keep);
 212                 }
 213                 if (!strncmp(buf, "vga", 3) &&
 214                     boot_params.screen_info.orig_video_isVGA == 1) {
 215                         max_xpos = boot_params.screen_info.orig_video_cols;
 216                         max_ypos = boot_params.screen_info.orig_video_lines;
 217                         current_ypos = boot_params.screen_info.orig_y;
 218                         early_console_register(&early_vga_console, keep);
 219                 }
 220 #ifdef CONFIG_EARLY_PRINTK_DBGP
 221                 if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
 222                         early_console_register(&early_dbgp_console, keep);
 223 #endif
 224 #ifdef CONFIG_HVC_XEN
 225                 if (!strncmp(buf, "xen", 3))
 226                         early_console_register(&xenboot_console, keep);
 227 #endif
 228 #ifdef CONFIG_EARLY_PRINTK_INTEL_MID
 229                 if (!strncmp(buf, "mrst", 4)) {
 230                         mrst_early_console_init();
 231                         early_console_register(&early_mrst_console, keep);
 232                 }
 233
 234                 if (!strncmp(buf, "hsu", 3)) {
 235                         hsu_early_console_init(buf + 3);
 236                         early_console_register(&early_hsu_console, keep);
 237                 }
 238 #endif
 239 #ifdef CONFIG_EARLY_PRINTK_EFI
 240                 if (!strncmp(buf, "efi", 3))
 241                         early_console_register(&early_efi_console, keep);
 242 #endif
 243
 244                 buf++;
 245         }
 246         return 0;
 247 }
 248
 249 early_param("earlyprintk", setup_early_printk);