[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-changelog] early_printk.c:



ChangeSet 1.1159.282.1, 2005/05/16 10:49:20+01:00, cl349@xxxxxxxxxxxxxxxxxxxx

        early_printk.c:
          Add support for CONFIG_EARLY_PRINTK over Xen's serial console.
          new file
        Signed-off-by: Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>



 early_printk.c |  242 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 242 insertions(+)


diff -Nru a/linux-2.6.11-xen-sparse/arch/xen/x86_64/kernel/early_printk.c 
b/linux-2.6.11-xen-sparse/arch/xen/x86_64/kernel/early_printk.c
--- /dev/null   Wed Dec 31 16:00:00 196900
+++ b/linux-2.6.11-xen-sparse/arch/xen/x86_64/kernel/early_printk.c     
2005-05-16 07:04:48 -04:00
@@ -0,0 +1,242 @@
+#include <linux/config.h>
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+
+/* Simple VGA output */
+
+#ifdef __i386__
+#define VGABASE                (__ISA_IO_base + 0xb8000)
+#else
+#define VGABASE                ((void __iomem *)0xffffffff800b8000UL)
+#endif
+
+#define MAX_YPOS       25
+#define MAX_XPOS       80
+
+static int current_ypos = 1, current_xpos = 0; 
+
+static void early_vga_write(struct console *con, const char *str, unsigned n)
+{
+       char c;
+       int  i, k, j;
+
+       while ((c = *str++) != '\0' && n-- > 0) {
+               if (current_ypos >= MAX_YPOS) {
+                       /* scroll 1 line up */
+                       for (k = 1, j = 0; k < MAX_YPOS; k++, j++) {
+                               for (i = 0; i < MAX_XPOS; i++) {
+                                       writew(readw(VGABASE + 2*(MAX_XPOS*k + 
i)),
+                                              VGABASE + 2*(MAX_XPOS*j + i));
+                               }
+                       }
+                       for (i = 0; i < MAX_XPOS; i++)
+                               writew(0x720, VGABASE + 2*(MAX_XPOS*j + i));
+                       current_ypos = MAX_YPOS-1;
+               }
+               if (c == '\n') {
+                       current_xpos = 0;
+                       current_ypos++;
+               } else if (c != '\r')  {
+                       writew(((0x7 << 8) | (unsigned short) c),
+                              VGABASE + 2*(MAX_XPOS*current_ypos +
+                                               current_xpos++));
+                       if (current_xpos >= MAX_XPOS) {
+                               current_xpos = 0;
+                               current_ypos++;
+                       }
+               }
+       }
+}
+
+static struct console early_vga_console = {
+       .name =         "earlyvga",
+       .write =        early_vga_write,
+       .flags =        CON_PRINTBUFFER,
+       .index =        -1,
+};
+
+#ifndef CONFIG_XEN
+/* Serial functions loosely based on a similar package from Klaus P. Gerlicher 
*/ 
+
+int early_serial_base = 0x3f8;  /* ttyS0 */ 
+
+#define XMTRDY          0x20
+
+#define DLAB           0x80
+
+#define TXR             0       /*  Transmit register (WRITE) */
+#define RXR             0       /*  Receive register  (READ)  */
+#define IER             1       /*  Interrupt Enable          */
+#define IIR             2       /*  Interrupt ID              */
+#define FCR             2       /*  FIFO control              */
+#define LCR             3       /*  Line control              */
+#define MCR             4       /*  Modem control             */
+#define LSR             5       /*  Line Status               */
+#define MSR             6       /*  Modem Status              */
+#define DLL             0       /*  Divisor Latch Low         */
+#define DLH             1       /*  Divisor latch High        */
+
+static int early_serial_putc(unsigned char ch) 
+{ 
+       unsigned timeout = 0xffff; 
+       while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout) 
+               cpu_relax();
+       outb(ch, early_serial_base + TXR);
+       return timeout ? 0 : -1;
+} 
+
+static void early_serial_write(struct console *con, const char *s, unsigned n)
+{
+       while (*s && n-- > 0) { 
+               early_serial_putc(*s); 
+               if (*s == '\n') 
+                       early_serial_putc('\r'); 
+               s++; 
+       } 
+} 
+
+#define DEFAULT_BAUD 9600
+
+static __init void early_serial_init(char *s)
+{
+       unsigned char c; 
+       unsigned divisor;
+       unsigned baud = DEFAULT_BAUD;
+       char *e;
+
+       if (*s == ',')
+               ++s;
+
+       if (*s) {
+               unsigned port; 
+               if (!strncmp(s,"0x",2)) {
+                       early_serial_base = simple_strtoul(s, &e, 16);
+               } else {
+                       static int bases[] = { 0x3f8, 0x2f8 };
+
+                       if (!strncmp(s,"ttyS",4))
+                               s += 4;
+                       port = simple_strtoul(s, &e, 10);
+                       if (port > 1 || s == e)
+                               port = 0;
+                       early_serial_base = bases[port];
+               }
+               s += strcspn(s, ",");
+               if (*s == ',')
+                       s++;
+       }
+
+       outb(0x3, early_serial_base + LCR);     /* 8n1 */
+       outb(0, early_serial_base + IER);       /* no interrupt */
+       outb(0, early_serial_base + FCR);       /* no fifo */
+       outb(0x3, early_serial_base + MCR);     /* DTR + RTS */
+
+       if (*s) {
+               baud = simple_strtoul(s, &e, 0); 
+               if (baud == 0 || s == e) 
+                       baud = DEFAULT_BAUD;
+       } 
+       
+       divisor = 115200 / baud; 
+       c = inb(early_serial_base + LCR); 
+       outb(c | DLAB, early_serial_base + LCR); 
+       outb(divisor & 0xff, early_serial_base + DLL); 
+       outb((divisor >> 8) & 0xff, early_serial_base + DLH); 
+       outb(c & ~DLAB, early_serial_base + LCR);
+}
+#else
+
+static void
+early_serial_write(struct console *con, const char *s, unsigned count)
+{
+       int n;
+
+       while (count > 0) {
+               n = HYPERVISOR_console_io(CONSOLEIO_write, count, (char *)s);
+               if (n <= 0)
+                       break;
+               count -= n;
+               s += n;
+       }
+} 
+
+static __init void early_serial_init(char *s)
+{
+}
+#endif
+
+static struct console early_serial_console = {
+       .name =         "earlyser",
+       .write =        early_serial_write,
+       .flags =        CON_PRINTBUFFER,
+       .index =        -1,
+};
+
+/* Direct interface for emergencies */
+struct console *early_console = &early_vga_console;
+static int early_console_initialized = 0;
+
+void early_printk(const char *fmt, ...)
+{ 
+       char buf[512]; 
+       int n; 
+       va_list ap;
+
+       va_start(ap,fmt); 
+       n = vscnprintf(buf,512,fmt,ap);
+       early_console->write(early_console,buf,n);
+       va_end(ap); 
+} 
+
+static int keep_early; 
+
+int __init setup_early_printk(char *opt) 
+{  
+       char *space;
+       char buf[256]; 
+
+       if (early_console_initialized)
+               return -1;
+
+       opt = strchr(opt, '=') + 1;
+
+       strlcpy(buf,opt,sizeof(buf)); 
+       space = strchr(buf, ' '); 
+       if (space)
+               *space = 0; 
+
+       if (strstr(buf,"keep"))
+               keep_early = 1; 
+
+       if (!strncmp(buf, "serial", 6)) { 
+               early_serial_init(buf + 6);
+               early_console = &early_serial_console;
+       } else if (!strncmp(buf, "ttyS", 4)) { 
+               early_serial_init(buf);
+               early_console = &early_serial_console;          
+       } else if (!strncmp(buf, "vga", 3)) {
+               early_console = &early_vga_console; 
+       }
+       early_console_initialized = 1;
+       register_console(early_console);       
+       return 0;
+}
+
+void __init disable_early_printk(void)
+{ 
+       if (!early_console_initialized || !early_console)
+               return;
+       if (!keep_early) {
+               printk("disabling early console\n");
+               unregister_console(early_console);
+               early_console_initialized = 0;
+       } else { 
+               printk("keeping early console\n");
+       }
+} 
+
+__setup("earlyprintk=", setup_early_printk);

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.