arch/x86/kernel/early_printk.c - linux - Git at Google

 #include <linux/console.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/string.h>
 #include <linux/screen_info.h>
 #include <linux/usb/ch9.h>
 #include <linux/pci_regs.h>
 #include <linux/pci_ids.h>
 #include <linux/errno.h>
 #include <asm/io.h>
 #include <asm/processor.h>
 #include <asm/fcntl.h>
 #include <asm/setup.h>
 #include <xen/hvc-console.h>
 #include <asm/pci-direct.h>
 #include <asm/fixmap.h>
 #include <asm/intel-mid.h>
 #include <asm/pgtable.h>
 #include <linux/usb/ehci_def.h>
 #include <linux/efi.h>
 #include <asm/efi.h>
 #include <asm/pci_x86.h>

 /* Simple VGA output */
 #define VGABASE		(__ISA_IO_base + 0xb8000)

 static int max_ypos = 25, max_xpos = 80;
 static int current_ypos = 25, current_xpos;

 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;
 		}
 #ifdef CONFIG_KGDB_KDB
 		if (c == '\b') {
 			if (current_xpos > 0)
 				current_xpos--;
 		} else if (c == '\r') {
 			current_xpos = 0;
 		} else
 #endif
 		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,
 };

 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */

 static unsigned long 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 void mem32_serial_out(unsigned long addr, int offset, int value)
 {
 	uint32_t *vaddr = (uint32_t *)addr;
 	/* shift implied by pointer type */
 	writel(value, vaddr + offset);
 }

 static unsigned int mem32_serial_in(unsigned long addr, int offset)
 {
 	uint32_t *vaddr = (uint32_t *)addr;
 	/* shift implied by pointer type */
 	return readl(vaddr + offset);
 }

 static unsigned int io_serial_in(unsigned long addr, int offset)
 {
 	return inb(addr + offset);
 }

 static void io_serial_out(unsigned long addr, int offset, int value)
 {
 	outb(value, addr + offset);
 }

 static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
 static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;

 static int early_serial_putc(unsigned char ch)
 {
 	unsigned timeout = 0xffff;

 	while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
 		cpu_relax();
 	serial_out(early_serial_base, TXR, ch);
 	return timeout ? 0 : -1;
 }

 static void early_serial_write(struct console *con, const char *s, unsigned n)
 {
 	while (*s && n-- > 0) {
 		if (*s == '\n')
 			early_serial_putc('\r');
 		early_serial_putc(*s);
 		s++;
 	}
 }

 static __init void early_serial_hw_init(unsigned divisor)
 {
 	unsigned char c;

 	serial_out(early_serial_base, LCR, 0x3);	/* 8n1 */
 	serial_out(early_serial_base, IER, 0);	/* no interrupt */
 	serial_out(early_serial_base, FCR, 0);	/* no fifo */
 	serial_out(early_serial_base, MCR, 0x3);	/* DTR + RTS */

 	c = serial_in(early_serial_base, LCR);
 	serial_out(early_serial_base, LCR, c | DLAB);
 	serial_out(early_serial_base, DLL, divisor & 0xff);
 	serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
 	serial_out(early_serial_base, LCR, c & ~DLAB);
 }

 #define DEFAULT_BAUD 9600

 static __init void early_serial_init(char *s)
 {
 	unsigned divisor;
 	unsigned long 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 const int __initconst 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++;
 	}

 	if (*s) {
 		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
 			baud = DEFAULT_BAUD;
 	}

 	/* Convert from baud to divisor value */
 	divisor = 115200 / baud;

 	/* These will always be IO based ports */
 	serial_in = io_serial_in;
 	serial_out = io_serial_out;

 	/* Set up the HW */
 	early_serial_hw_init(divisor);
 }

 #ifdef CONFIG_PCI
 /*
  * early_pci_serial_init()
  *
  * This function is invoked when the early_printk param starts with "pciserial"
  * The rest of the param should be ",B:D.F,baud" where B, D & F describe the
  * location of a PCI device that must be a UART device.
  */
 static __init void early_pci_serial_init(char *s)
 {
 	unsigned divisor;
 	unsigned long baud = DEFAULT_BAUD;
 	u8 bus, slot, func;
 	uint32_t classcode, bar0;
 	uint16_t cmdreg;
 	char *e;


 	/*
 	 * First, part the param to get the BDF values
 	 */
 	if (*s == ',')
 		++s;

 	if (*s == 0)
 		return;

 	bus = (u8)simple_strtoul(s, &e, 16);
 	s = e;
 	if (*s != ':')
 		return;
 	++s;
 	slot = (u8)simple_strtoul(s, &e, 16);
 	s = e;
 	if (*s != '.')
 		return;
 	++s;
 	func = (u8)simple_strtoul(s, &e, 16);
 	s = e;

 	/* A baud might be following */
 	if (*s == ',')
 		s++;

 	/*
 	 * Second, find the device from the BDF
 	 */
 	cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
 	classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
 	bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);

 	/*
 	 * Verify it is a UART type device
 	 */
 	if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
 	     (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
 	   (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */
 		return;

 	/*
 	 * Determine if it is IO or memory mapped
 	 */
 	if (bar0 & 0x01) {
 		/* it is IO mapped */
 		serial_in = io_serial_in;
 		serial_out = io_serial_out;
 		early_serial_base = bar0&0xfffffffc;
 		write_pci_config(bus, slot, func, PCI_COMMAND,
 						cmdreg|PCI_COMMAND_IO);
 	} else {
 		/* It is memory mapped - assume 32-bit alignment */
 		serial_in = mem32_serial_in;
 		serial_out = mem32_serial_out;
 		/* WARNING! assuming the address is always in the first 4G */
 		early_serial_base =
 			(unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
 		write_pci_config(bus, slot, func, PCI_COMMAND,
 						cmdreg|PCI_COMMAND_MEMORY);
 	}

 	/*
 	 * Lastly, initalize the hardware
 	 */
 	if (*s) {
 		if (strcmp(s, "nocfg") == 0)
 			/* Sometimes, we want to leave the UART alone
 			 * and assume the BIOS has set it up correctly.
 			 * "nocfg" tells us this is the case, and we
 			 * should do no more setup.
 			 */
 			return;
 		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
 			baud = DEFAULT_BAUD;
 	}

 	/* Convert from baud to divisor value */
 	divisor = 115200 / baud;

 	/* Set up the HW */
 	early_serial_hw_init(divisor);
 }
 #endif

 static struct console early_serial_console = {
 	.name =		"earlyser",
 	.write =	early_serial_write,
 	.flags =	CON_PRINTBUFFER,
 	.index =	-1,
 };

 static inline void early_console_register(struct console *con, int keep_early)
 {
 	if (con->index != -1) {
 		printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
 		       con->name);
 		return;
 	}
 	early_console = con;
 	if (keep_early)
 		early_console->flags &= ~CON_BOOT;
 	else
 		early_console->flags |= CON_BOOT;
 	register_console(early_console);
 }

 static int __init setup_early_printk(char *buf)
 {
 	int keep;

 	if (!buf)
 		return 0;

 	if (early_console)
 		return 0;

 	keep = (strstr(buf, "keep") != NULL);

 	while (*buf != '\0') {
 		if (!strncmp(buf, "serial", 6)) {
 			buf += 6;
 			early_serial_init(buf);
 			early_console_register(&early_serial_console, keep);
 			if (!strncmp(buf, ",ttyS", 5))
 				buf += 5;
 		}
 		if (!strncmp(buf, "ttyS", 4)) {
 			early_serial_init(buf + 4);
 			early_console_register(&early_serial_console, keep);
 		}
 #ifdef CONFIG_PCI
 		if (!strncmp(buf, "pciserial", 9)) {
 			early_pci_serial_init(buf + 9);
 			early_console_register(&early_serial_console, keep);
 			buf += 9; /* Keep from match the above "serial" */
 		}
 #endif
 		if (!strncmp(buf, "vga", 3) &&
 		    boot_params.screen_info.orig_video_isVGA == 1) {
 			max_xpos = boot_params.screen_info.orig_video_cols;
 			max_ypos = boot_params.screen_info.orig_video_lines;
 			current_ypos = boot_params.screen_info.orig_y;
 			early_console_register(&early_vga_console, keep);
 		}
 #ifdef CONFIG_EARLY_PRINTK_DBGP
 		if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
 			early_console_register(&early_dbgp_console, keep);
 #endif
 #ifdef CONFIG_HVC_XEN
 		if (!strncmp(buf, "xen", 3))
 			early_console_register(&xenboot_console, keep);
 #endif
 #ifdef CONFIG_EARLY_PRINTK_INTEL_MID
 		if (!strncmp(buf, "hsu", 3)) {
 			hsu_early_console_init(buf + 3);
 			early_console_register(&early_hsu_console, keep);
 		}
 #endif
 #ifdef CONFIG_EARLY_PRINTK_EFI
 		if (!strncmp(buf, "efi", 3))
 			early_console_register(&early_efi_console, keep);
 #endif

 		buf++;
 	}
 	return 0;
 }

 early_param("earlyprintk", setup_early_printk);
	#include <linux/console.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/string.h>
	#include <linux/screen_info.h>
	#include <linux/usb/ch9.h>
	#include <linux/pci_regs.h>
	#include <linux/pci_ids.h>
	#include <linux/errno.h>
	#include <asm/io.h>
	#include <asm/processor.h>
	#include <asm/fcntl.h>
	#include <asm/setup.h>
	#include <xen/hvc-console.h>
	#include <asm/pci-direct.h>
	#include <asm/fixmap.h>
	#include <asm/intel-mid.h>
	#include <asm/pgtable.h>
	#include <linux/usb/ehci_def.h>
	#include <linux/efi.h>
	#include <asm/efi.h>
	#include <asm/pci_x86.h>

	/* Simple VGA output */
	#define VGABASE (__ISA_IO_base + 0xb8000)

	static int max_ypos = 25, max_xpos = 80;
	static int current_ypos = 25, current_xpos;

	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_xposk+i)),
	VGABASE + 2(max_xposj + i));
	}
	}
	for (i = 0; i < max_xpos; i++)
	writew(0x720, VGABASE + 2(max_xposj + i));
	current_ypos = max_ypos-1;
	}
	#ifdef CONFIG_KGDB_KDB
	if (c == '\b') {
	if (current_xpos > 0)
	current_xpos--;
	} else if (c == '\r') {
	current_xpos = 0;
	} else
	#endif
	if (c == '\n') {
	current_xpos = 0;
	current_ypos++;
	} else if (c != '\r') {
	writew(((0x7 << 8) \| (unsigned short) c),
	VGABASE + 2(max_xposcurrent_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,
	};

	/* Serial functions loosely based on a similar package from Klaus P. Gerlicher */

	static unsigned long 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 void mem32_serial_out(unsigned long addr, int offset, int value)
	{
	uint32_t vaddr = (uint32_t )addr;
	/* shift implied by pointer type */
	writel(value, vaddr + offset);
	}

	static unsigned int mem32_serial_in(unsigned long addr, int offset)
	{
	uint32_t vaddr = (uint32_t )addr;
	/* shift implied by pointer type */
	return readl(vaddr + offset);
	}

	static unsigned int io_serial_in(unsigned long addr, int offset)
	{
	return inb(addr + offset);
	}

	static void io_serial_out(unsigned long addr, int offset, int value)
	{
	outb(value, addr + offset);
	}

	static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
	static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;

	static int early_serial_putc(unsigned char ch)
	{
	unsigned timeout = 0xffff;

	while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
	cpu_relax();
	serial_out(early_serial_base, TXR, ch);
	return timeout ? 0 : -1;
	}

	static void early_serial_write(struct console con, const char s, unsigned n)
	{
	while (*s && n-- > 0) {
	if (*s == '\n')
	early_serial_putc('\r');
	early_serial_putc(*s);
	s++;
	}
	}

	static __init void early_serial_hw_init(unsigned divisor)
	{
	unsigned char c;

	serial_out(early_serial_base, LCR, 0x3); /* 8n1 */
	serial_out(early_serial_base, IER, 0); /* no interrupt */
	serial_out(early_serial_base, FCR, 0); /* no fifo */
	serial_out(early_serial_base, MCR, 0x3); /* DTR + RTS */

	c = serial_in(early_serial_base, LCR);
	serial_out(early_serial_base, LCR, c \| DLAB);
	serial_out(early_serial_base, DLL, divisor & 0xff);
	serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
	serial_out(early_serial_base, LCR, c & ~DLAB);
	}

	#define DEFAULT_BAUD 9600

	static __init void early_serial_init(char *s)
	{
	unsigned divisor;
	unsigned long 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 const int __initconst 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++;
	}

	if (*s) {
	if (kstrtoul(s, 0, &baud) < 0 \|\| baud == 0)
	baud = DEFAULT_BAUD;
	}

	/* Convert from baud to divisor value */
	divisor = 115200 / baud;

	/* These will always be IO based ports */
	serial_in = io_serial_in;
	serial_out = io_serial_out;

	/* Set up the HW */
	early_serial_hw_init(divisor);
	}

	#ifdef CONFIG_PCI
	/*
	* early_pci_serial_init()
	*
	* This function is invoked when the early_printk param starts with "pciserial"
	* The rest of the param should be ",B:D.F,baud" where B, D & F describe the
	* location of a PCI device that must be a UART device.
	*/
	static __init void early_pci_serial_init(char *s)
	{
	unsigned divisor;
	unsigned long baud = DEFAULT_BAUD;
	u8 bus, slot, func;
	uint32_t classcode, bar0;
	uint16_t cmdreg;
	char *e;


	/*
	* First, part the param to get the BDF values
	*/
	if (*s == ',')
	++s;

	if (*s == 0)
	return;

	bus = (u8)simple_strtoul(s, &e, 16);
	s = e;
	if (*s != ':')
	return;
	++s;
	slot = (u8)simple_strtoul(s, &e, 16);
	s = e;
	if (*s != '.')
	return;
	++s;
	func = (u8)simple_strtoul(s, &e, 16);
	s = e;

	/* A baud might be following */
	if (*s == ',')
	s++;

	/*
	* Second, find the device from the BDF
	*/
	cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
	classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
	bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);

	/*
	* Verify it is a UART type device
	*/
	if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
	(classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) \|\|
	(((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */
	return;

	/*
	* Determine if it is IO or memory mapped
	*/
	if (bar0 & 0x01) {
	/* it is IO mapped */
	serial_in = io_serial_in;
	serial_out = io_serial_out;
	early_serial_base = bar0&0xfffffffc;
	write_pci_config(bus, slot, func, PCI_COMMAND,
	cmdreg\|PCI_COMMAND_IO);
	} else {
	/* It is memory mapped - assume 32-bit alignment */
	serial_in = mem32_serial_in;
	serial_out = mem32_serial_out;
	/* WARNING! assuming the address is always in the first 4G */
	early_serial_base =
	(unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
	write_pci_config(bus, slot, func, PCI_COMMAND,
	cmdreg\|PCI_COMMAND_MEMORY);
	}

	/*
	* Lastly, initalize the hardware
	*/
	if (*s) {
	if (strcmp(s, "nocfg") == 0)
	/* Sometimes, we want to leave the UART alone
	* and assume the BIOS has set it up correctly.
	* "nocfg" tells us this is the case, and we
	* should do no more setup.
	*/
	return;
	if (kstrtoul(s, 0, &baud) < 0 \|\| baud == 0)
	baud = DEFAULT_BAUD;
	}

	/* Convert from baud to divisor value */
	divisor = 115200 / baud;

	/* Set up the HW */
	early_serial_hw_init(divisor);
	}
	#endif

	static struct console early_serial_console = {
	.name = "earlyser",
	.write = early_serial_write,
	.flags = CON_PRINTBUFFER,
	.index = -1,
	};

	static inline void early_console_register(struct console *con, int keep_early)
	{
	if (con->index != -1) {
	printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
	con->name);
	return;
	}
	early_console = con;
	if (keep_early)
	early_console->flags &= ~CON_BOOT;
	else
	early_console->flags \|= CON_BOOT;
	register_console(early_console);
	}

	static int __init setup_early_printk(char *buf)
	{
	int keep;

	if (!buf)
	return 0;

	if (early_console)
	return 0;

	keep = (strstr(buf, "keep") != NULL);

	while (*buf != '\0') {
	if (!strncmp(buf, "serial", 6)) {
	buf += 6;
	early_serial_init(buf);
	early_console_register(&early_serial_console, keep);
	if (!strncmp(buf, ",ttyS", 5))
	buf += 5;
	}
	if (!strncmp(buf, "ttyS", 4)) {
	early_serial_init(buf + 4);
	early_console_register(&early_serial_console, keep);
	}
	#ifdef CONFIG_PCI
	if (!strncmp(buf, "pciserial", 9)) {
	early_pci_serial_init(buf + 9);
	early_console_register(&early_serial_console, keep);
	buf += 9; /* Keep from match the above "serial" */
	}
	#endif
	if (!strncmp(buf, "vga", 3) &&
	boot_params.screen_info.orig_video_isVGA == 1) {
	max_xpos = boot_params.screen_info.orig_video_cols;
	max_ypos = boot_params.screen_info.orig_video_lines;
	current_ypos = boot_params.screen_info.orig_y;
	early_console_register(&early_vga_console, keep);
	}
	#ifdef CONFIG_EARLY_PRINTK_DBGP
	if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
	early_console_register(&early_dbgp_console, keep);
	#endif
	#ifdef CONFIG_HVC_XEN
	if (!strncmp(buf, "xen", 3))
	early_console_register(&xenboot_console, keep);
	#endif
	#ifdef CONFIG_EARLY_PRINTK_INTEL_MID
	if (!strncmp(buf, "hsu", 3)) {
	hsu_early_console_init(buf + 3);
	early_console_register(&early_hsu_console, keep);
	}
	#endif
	#ifdef CONFIG_EARLY_PRINTK_EFI
	if (!strncmp(buf, "efi", 3))
	early_console_register(&early_efi_console, keep);
	#endif

	buf++;
	}
	return 0;
	}

	early_param("earlyprintk", setup_early_printk);