69331af79c
The console subsystem already has an idea of a boot console, using the CON_BOOT flag. The implementation has some flaws though. The major problem is that presence of a boot console makes register_console() ignore any other console devices (unless explicitly specified on the kernel command line). This patch fixes the console selection code to *not* consider a boot console a full-featured one, so the first non-boot console registering will become the default console instead. This way the unregister call for the boot console in the register_console() function actually triggers and the handover from the boot console to the real console device works smoothly. Added a printk for the handover, so you know which console device the output goes to when the boot console stops printing messages. The disable_early_printk() call is obsolete with that patch, explicitly disabling the early console isn't needed any more as it works automagically with that patch. I've walked through the tree, dropped all disable_early_printk() instances found below arch/ and tagged the consoles with CON_BOOT if needed. The code is tested on x86, sh (thanks to Paul) and mips (thanks to Ralf). Changes to last version: Rediffed against -rc3, adapted to mips cleanups by Ralf, fixed "udbg-immortal" cmd line arg on powerpc. Signed-off-by: Gerd Hoffmann <kraxel@exsuse.de> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Andi Kleen <ak@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
255 lines
6.0 KiB
C
255 lines
6.0 KiB
C
#include <linux/console.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/screen_info.h>
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#include <asm/io.h>
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#include <asm/processor.h>
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#include <asm/fcntl.h>
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/* Simple VGA output */
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#ifdef __i386__
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#include <asm/setup.h>
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#else
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#include <asm/bootsetup.h>
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#endif
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#define VGABASE (__ISA_IO_base + 0xb8000)
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static int max_ypos = 25, max_xpos = 80;
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static int current_ypos = 25, current_xpos = 0;
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static void early_vga_write(struct console *con, const char *str, unsigned n)
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{
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char c;
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int i, k, j;
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while ((c = *str++) != '\0' && n-- > 0) {
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if (current_ypos >= max_ypos) {
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/* scroll 1 line up */
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for (k = 1, j = 0; k < max_ypos; k++, j++) {
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for (i = 0; i < max_xpos; i++) {
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writew(readw(VGABASE+2*(max_xpos*k+i)),
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VGABASE + 2*(max_xpos*j + i));
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}
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}
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for (i = 0; i < max_xpos; i++)
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writew(0x720, VGABASE + 2*(max_xpos*j + i));
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current_ypos = max_ypos-1;
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}
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if (c == '\n') {
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current_xpos = 0;
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current_ypos++;
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} else if (c != '\r') {
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writew(((0x7 << 8) | (unsigned short) c),
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VGABASE + 2*(max_xpos*current_ypos +
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current_xpos++));
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if (current_xpos >= max_xpos) {
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current_xpos = 0;
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current_ypos++;
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}
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}
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}
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}
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static struct console early_vga_console = {
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.name = "earlyvga",
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.write = early_vga_write,
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.flags = CON_PRINTBUFFER,
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.index = -1,
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};
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/* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
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static int early_serial_base = 0x3f8; /* ttyS0 */
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#define XMTRDY 0x20
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#define DLAB 0x80
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#define TXR 0 /* Transmit register (WRITE) */
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#define RXR 0 /* Receive register (READ) */
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#define IER 1 /* Interrupt Enable */
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#define IIR 2 /* Interrupt ID */
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#define FCR 2 /* FIFO control */
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#define LCR 3 /* Line control */
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#define MCR 4 /* Modem control */
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#define LSR 5 /* Line Status */
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#define MSR 6 /* Modem Status */
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#define DLL 0 /* Divisor Latch Low */
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#define DLH 1 /* Divisor latch High */
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static int early_serial_putc(unsigned char ch)
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{
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unsigned timeout = 0xffff;
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while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
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cpu_relax();
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outb(ch, early_serial_base + TXR);
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return timeout ? 0 : -1;
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}
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static void early_serial_write(struct console *con, const char *s, unsigned n)
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{
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while (*s && n-- > 0) {
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early_serial_putc(*s);
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if (*s == '\n')
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early_serial_putc('\r');
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s++;
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}
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}
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#define DEFAULT_BAUD 9600
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static __init void early_serial_init(char *s)
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{
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unsigned char c;
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unsigned divisor;
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unsigned baud = DEFAULT_BAUD;
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char *e;
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if (*s == ',')
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++s;
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if (*s) {
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unsigned port;
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if (!strncmp(s,"0x",2)) {
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early_serial_base = simple_strtoul(s, &e, 16);
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} else {
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static int bases[] = { 0x3f8, 0x2f8 };
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if (!strncmp(s,"ttyS",4))
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s += 4;
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port = simple_strtoul(s, &e, 10);
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if (port > 1 || s == e)
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port = 0;
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early_serial_base = bases[port];
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}
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s += strcspn(s, ",");
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if (*s == ',')
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s++;
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}
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outb(0x3, early_serial_base + LCR); /* 8n1 */
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outb(0, early_serial_base + IER); /* no interrupt */
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outb(0, early_serial_base + FCR); /* no fifo */
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outb(0x3, early_serial_base + MCR); /* DTR + RTS */
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if (*s) {
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baud = simple_strtoul(s, &e, 0);
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if (baud == 0 || s == e)
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baud = DEFAULT_BAUD;
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}
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divisor = 115200 / baud;
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c = inb(early_serial_base + LCR);
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outb(c | DLAB, early_serial_base + LCR);
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outb(divisor & 0xff, early_serial_base + DLL);
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outb((divisor >> 8) & 0xff, early_serial_base + DLH);
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outb(c & ~DLAB, early_serial_base + LCR);
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}
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static struct console early_serial_console = {
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.name = "earlyser",
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.write = early_serial_write,
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.flags = CON_PRINTBUFFER,
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.index = -1,
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};
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/* Console interface to a host file on AMD's SimNow! */
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static int simnow_fd;
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enum {
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MAGIC1 = 0xBACCD00A,
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MAGIC2 = 0xCA110000,
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XOPEN = 5,
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XWRITE = 4,
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};
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static noinline long simnow(long cmd, long a, long b, long c)
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{
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long ret;
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asm volatile("cpuid" :
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"=a" (ret) :
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"b" (a), "c" (b), "d" (c), "0" (MAGIC1), "D" (cmd + MAGIC2));
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return ret;
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}
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static void __init simnow_init(char *str)
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{
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char *fn = "klog";
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if (*str == '=')
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fn = ++str;
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/* error ignored */
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simnow_fd = simnow(XOPEN, (unsigned long)fn, O_WRONLY|O_APPEND|O_CREAT, 0644);
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}
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static void simnow_write(struct console *con, const char *s, unsigned n)
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{
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simnow(XWRITE, simnow_fd, (unsigned long)s, n);
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}
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static struct console simnow_console = {
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.name = "simnow",
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.write = simnow_write,
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.flags = CON_PRINTBUFFER,
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.index = -1,
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};
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/* Direct interface for emergencies */
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struct console *early_console = &early_vga_console;
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static int early_console_initialized = 0;
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void early_printk(const char *fmt, ...)
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{
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char buf[512];
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int n;
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va_list ap;
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va_start(ap,fmt);
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n = vscnprintf(buf,512,fmt,ap);
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early_console->write(early_console,buf,n);
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va_end(ap);
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}
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static int __initdata keep_early;
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static int __init setup_early_printk(char *buf)
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{
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if (!buf)
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return 0;
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if (early_console_initialized)
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return 0;
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early_console_initialized = 1;
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if (strstr(buf, "keep"))
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keep_early = 1;
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if (!strncmp(buf, "serial", 6)) {
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early_serial_init(buf + 6);
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early_console = &early_serial_console;
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} else if (!strncmp(buf, "ttyS", 4)) {
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early_serial_init(buf);
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early_console = &early_serial_console;
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} else if (!strncmp(buf, "vga", 3)
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&& SCREEN_INFO.orig_video_isVGA == 1) {
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max_xpos = SCREEN_INFO.orig_video_cols;
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max_ypos = SCREEN_INFO.orig_video_lines;
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current_ypos = SCREEN_INFO.orig_y;
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early_console = &early_vga_console;
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} else if (!strncmp(buf, "simnow", 6)) {
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simnow_init(buf + 6);
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early_console = &simnow_console;
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keep_early = 1;
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}
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if (keep_early)
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early_console->flags &= ~CON_BOOT;
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else
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early_console->flags |= CON_BOOT;
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register_console(early_console);
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return 0;
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}
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early_param("earlyprintk", setup_early_printk);
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