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61eaf539b9
Allow kdb to work properly with with earlyprintk=vga by interpreting the backspace and carriage return output characters. These interpretation of these characters is used for simple line editing provided in the kdb shell. CC: Thomas Gleixner <tglx@linutronix.de> CC: Ingo Molnar <mingo@redhat.com> CC: H. Peter Anvin <hpa@zytor.com> CC: x86@kernel.org Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
248 lines
6.1 KiB
C
248 lines
6.1 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 <linux/usb/ch9.h>
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#include <linux/pci_regs.h>
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#include <linux/pci_ids.h>
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#include <linux/errno.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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#include <asm/setup.h>
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#include <xen/hvc-console.h>
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#include <asm/pci-direct.h>
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#include <asm/fixmap.h>
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#include <asm/pgtable.h>
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#include <linux/usb/ehci_def.h>
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/* Simple VGA output */
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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;
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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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#ifdef CONFIG_KGDB_KDB
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if (c == '\b') {
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if (current_xpos > 0)
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current_xpos--;
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} else if (c == '\r') {
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current_xpos = 0;
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} else
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#endif
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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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if (*s == '\n')
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early_serial_putc('\r');
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early_serial_putc(*s);
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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 const int __initconst 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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/* Direct interface for emergencies */
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static struct console *early_console = &early_vga_console;
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static int __initdata early_console_initialized;
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asmlinkage 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, sizeof(buf), 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 inline void early_console_register(struct console *con, int keep_early)
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{
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if (early_console->index != -1) {
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printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
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con->name);
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return;
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}
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early_console = con;
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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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}
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static int __init setup_early_printk(char *buf)
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{
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int keep;
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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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keep = (strstr(buf, "keep") != NULL);
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while (*buf != '\0') {
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if (!strncmp(buf, "serial", 6)) {
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buf += 6;
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early_serial_init(buf);
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early_console_register(&early_serial_console, keep);
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if (!strncmp(buf, ",ttyS", 5))
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buf += 5;
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}
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if (!strncmp(buf, "ttyS", 4)) {
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early_serial_init(buf + 4);
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early_console_register(&early_serial_console, keep);
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}
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if (!strncmp(buf, "vga", 3) &&
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boot_params.screen_info.orig_video_isVGA == 1) {
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max_xpos = boot_params.screen_info.orig_video_cols;
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max_ypos = boot_params.screen_info.orig_video_lines;
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current_ypos = boot_params.screen_info.orig_y;
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early_console_register(&early_vga_console, keep);
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}
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#ifdef CONFIG_EARLY_PRINTK_DBGP
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if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
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early_console_register(&early_dbgp_console, keep);
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#endif
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#ifdef CONFIG_HVC_XEN
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if (!strncmp(buf, "xen", 3))
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early_console_register(&xenboot_console, keep);
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#endif
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buf++;
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}
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return 0;
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}
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early_param("earlyprintk", setup_early_printk);
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