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>
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/pgtable.h>
18 #include <linux/usb/ehci_def.h>
20 /* Simple VGA output */
21 #define VGABASE (__ISA_IO_base + 0xb8000)
23 static int max_ypos
= 25, max_xpos
= 80;
24 static int current_ypos
= 25, current_xpos
;
26 static void early_vga_write(struct console
*con
, const char *str
, unsigned n
)
31 while ((c
= *str
++) != '\0' && n
-- > 0) {
32 if (current_ypos
>= max_ypos
) {
33 /* scroll 1 line up */
34 for (k
= 1, j
= 0; k
< max_ypos
; k
++, j
++) {
35 for (i
= 0; i
< max_xpos
; i
++) {
36 writew(readw(VGABASE
+2*(max_xpos
*k
+i
)),
37 VGABASE
+ 2*(max_xpos
*j
+ i
));
40 for (i
= 0; i
< max_xpos
; i
++)
41 writew(0x720, VGABASE
+ 2*(max_xpos
*j
+ i
));
42 current_ypos
= max_ypos
-1;
47 } else if (c
!= '\r') {
48 writew(((0x7 << 8) | (unsigned short) c
),
49 VGABASE
+ 2*(max_xpos
*current_ypos
+
51 if (current_xpos
>= max_xpos
) {
59 static struct console early_vga_console
= {
61 .write
= early_vga_write
,
62 .flags
= CON_PRINTBUFFER
,
66 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
68 static int early_serial_base
= 0x3f8; /* ttyS0 */
74 #define TXR 0 /* Transmit register (WRITE) */
75 #define RXR 0 /* Receive register (READ) */
76 #define IER 1 /* Interrupt Enable */
77 #define IIR 2 /* Interrupt ID */
78 #define FCR 2 /* FIFO control */
79 #define LCR 3 /* Line control */
80 #define MCR 4 /* Modem control */
81 #define LSR 5 /* Line Status */
82 #define MSR 6 /* Modem Status */
83 #define DLL 0 /* Divisor Latch Low */
84 #define DLH 1 /* Divisor latch High */
86 static int early_serial_putc(unsigned char ch
)
88 unsigned timeout
= 0xffff;
90 while ((inb(early_serial_base
+ LSR
) & XMTRDY
) == 0 && --timeout
)
92 outb(ch
, early_serial_base
+ TXR
);
93 return timeout
? 0 : -1;
96 static void early_serial_write(struct console
*con
, const char *s
, unsigned n
)
98 while (*s
&& n
-- > 0) {
100 early_serial_putc('\r');
101 early_serial_putc(*s
);
106 #define DEFAULT_BAUD 9600
108 static __init
void early_serial_init(char *s
)
112 unsigned baud
= DEFAULT_BAUD
;
120 if (!strncmp(s
, "0x", 2)) {
121 early_serial_base
= simple_strtoul(s
, &e
, 16);
123 static const int __initconst bases
[] = { 0x3f8, 0x2f8 };
125 if (!strncmp(s
, "ttyS", 4))
127 port
= simple_strtoul(s
, &e
, 10);
128 if (port
> 1 || s
== e
)
130 early_serial_base
= bases
[port
];
132 s
+= strcspn(s
, ",");
137 outb(0x3, early_serial_base
+ LCR
); /* 8n1 */
138 outb(0, early_serial_base
+ IER
); /* no interrupt */
139 outb(0, early_serial_base
+ FCR
); /* no fifo */
140 outb(0x3, early_serial_base
+ MCR
); /* DTR + RTS */
143 baud
= simple_strtoul(s
, &e
, 0);
144 if (baud
== 0 || s
== e
)
148 divisor
= 115200 / baud
;
149 c
= inb(early_serial_base
+ LCR
);
150 outb(c
| DLAB
, early_serial_base
+ LCR
);
151 outb(divisor
& 0xff, early_serial_base
+ DLL
);
152 outb((divisor
>> 8) & 0xff, early_serial_base
+ DLH
);
153 outb(c
& ~DLAB
, early_serial_base
+ LCR
);
156 static struct console early_serial_console
= {
158 .write
= early_serial_write
,
159 .flags
= CON_PRINTBUFFER
,
163 #ifdef CONFIG_EARLY_PRINTK_DBGP
165 static struct ehci_caps __iomem
*ehci_caps
;
166 static struct ehci_regs __iomem
*ehci_regs
;
167 static struct ehci_dbg_port __iomem
*ehci_debug
;
168 static unsigned int dbgp_endpoint_out
;
176 static struct ehci_dev ehci_dev
;
178 #define USB_DEBUG_DEVNUM 127
180 #define DBGP_DATA_TOGGLE 0x8800
182 static inline u32
dbgp_pid_update(u32 x
, u32 tok
)
184 return ((x
^ DBGP_DATA_TOGGLE
) & 0xffff00) | (tok
& 0xff);
187 static inline u32
dbgp_len_update(u32 x
, u32 len
)
189 return (x
& ~0x0f) | (len
& 0x0f);
193 * USB Packet IDs (PIDs)
197 #define USB_PID_OUT 0xe1
198 #define USB_PID_IN 0x69
199 #define USB_PID_SOF 0xa5
200 #define USB_PID_SETUP 0x2d
202 #define USB_PID_ACK 0xd2
203 #define USB_PID_NAK 0x5a
204 #define USB_PID_STALL 0x1e
205 #define USB_PID_NYET 0x96
207 #define USB_PID_DATA0 0xc3
208 #define USB_PID_DATA1 0x4b
209 #define USB_PID_DATA2 0x87
210 #define USB_PID_MDATA 0x0f
212 #define USB_PID_PREAMBLE 0x3c
213 #define USB_PID_ERR 0x3c
214 #define USB_PID_SPLIT 0x78
215 #define USB_PID_PING 0xb4
216 #define USB_PID_UNDEF_0 0xf0
218 #define USB_PID_DATA_TOGGLE 0x88
219 #define DBGP_CLAIM (DBGP_OWNER | DBGP_ENABLED | DBGP_INUSE)
221 #define PCI_CAP_ID_EHCI_DEBUG 0xa
223 #define HUB_ROOT_RESET_TIME 50 /* times are in msec */
224 #define HUB_SHORT_RESET_TIME 10
225 #define HUB_LONG_RESET_TIME 200
226 #define HUB_RESET_TIMEOUT 500
228 #define DBGP_MAX_PACKET 8
230 static int dbgp_wait_until_complete(void)
236 ctrl
= readl(&ehci_debug
->control
);
237 /* Stop when the transaction is finished */
238 if (ctrl
& DBGP_DONE
)
240 } while (--loop
> 0);
246 * Now that we have observed the completed transaction,
247 * clear the done bit.
249 writel(ctrl
| DBGP_DONE
, &ehci_debug
->control
);
250 return (ctrl
& DBGP_ERROR
) ? -DBGP_ERRCODE(ctrl
) : DBGP_LEN(ctrl
);
253 static void __init
dbgp_mdelay(int ms
)
258 for (i
= 0; i
< 1000; i
++)
263 static void dbgp_breath(void)
265 /* Sleep to give the debug port a chance to breathe */
268 static int dbgp_wait_until_done(unsigned ctrl
)
275 writel(ctrl
| DBGP_GO
, &ehci_debug
->control
);
276 ret
= dbgp_wait_until_complete();
277 pids
= readl(&ehci_debug
->pids
);
278 lpid
= DBGP_PID_GET(pids
);
284 * If the port is getting full or it has dropped data
285 * start pacing ourselves, not necessary but it's friendly.
287 if ((lpid
== USB_PID_NAK
) || (lpid
== USB_PID_NYET
))
290 /* If I get a NACK reissue the transmission */
291 if (lpid
== USB_PID_NAK
) {
299 static void dbgp_set_data(const void *buf
, int size
)
301 const unsigned char *bytes
= buf
;
306 for (i
= 0; i
< 4 && i
< size
; i
++)
307 lo
|= bytes
[i
] << (8*i
);
308 for (; i
< 8 && i
< size
; i
++)
309 hi
|= bytes
[i
] << (8*(i
- 4));
310 writel(lo
, &ehci_debug
->data03
);
311 writel(hi
, &ehci_debug
->data47
);
314 static void __init
dbgp_get_data(void *buf
, int size
)
316 unsigned char *bytes
= buf
;
320 lo
= readl(&ehci_debug
->data03
);
321 hi
= readl(&ehci_debug
->data47
);
322 for (i
= 0; i
< 4 && i
< size
; i
++)
323 bytes
[i
] = (lo
>> (8*i
)) & 0xff;
324 for (; i
< 8 && i
< size
; i
++)
325 bytes
[i
] = (hi
>> (8*(i
- 4))) & 0xff;
328 static int dbgp_bulk_write(unsigned devnum
, unsigned endpoint
,
329 const char *bytes
, int size
)
331 u32 pids
, addr
, ctrl
;
334 if (size
> DBGP_MAX_PACKET
)
337 addr
= DBGP_EPADDR(devnum
, endpoint
);
339 pids
= readl(&ehci_debug
->pids
);
340 pids
= dbgp_pid_update(pids
, USB_PID_OUT
);
342 ctrl
= readl(&ehci_debug
->control
);
343 ctrl
= dbgp_len_update(ctrl
, size
);
347 dbgp_set_data(bytes
, size
);
348 writel(addr
, &ehci_debug
->address
);
349 writel(pids
, &ehci_debug
->pids
);
351 ret
= dbgp_wait_until_done(ctrl
);
358 static int __init
dbgp_bulk_read(unsigned devnum
, unsigned endpoint
, void *data
,
361 u32 pids
, addr
, ctrl
;
364 if (size
> DBGP_MAX_PACKET
)
367 addr
= DBGP_EPADDR(devnum
, endpoint
);
369 pids
= readl(&ehci_debug
->pids
);
370 pids
= dbgp_pid_update(pids
, USB_PID_IN
);
372 ctrl
= readl(&ehci_debug
->control
);
373 ctrl
= dbgp_len_update(ctrl
, size
);
377 writel(addr
, &ehci_debug
->address
);
378 writel(pids
, &ehci_debug
->pids
);
379 ret
= dbgp_wait_until_done(ctrl
);
385 dbgp_get_data(data
, size
);
389 static int __init
dbgp_control_msg(unsigned devnum
, int requesttype
,
390 int request
, int value
, int index
, void *data
, int size
)
392 u32 pids
, addr
, ctrl
;
393 struct usb_ctrlrequest req
;
397 read
= (requesttype
& USB_DIR_IN
) != 0;
398 if (size
> (read
? DBGP_MAX_PACKET
:0))
401 /* Compute the control message */
402 req
.bRequestType
= requesttype
;
403 req
.bRequest
= request
;
404 req
.wValue
= cpu_to_le16(value
);
405 req
.wIndex
= cpu_to_le16(index
);
406 req
.wLength
= cpu_to_le16(size
);
408 pids
= DBGP_PID_SET(USB_PID_DATA0
, USB_PID_SETUP
);
409 addr
= DBGP_EPADDR(devnum
, 0);
411 ctrl
= readl(&ehci_debug
->control
);
412 ctrl
= dbgp_len_update(ctrl
, sizeof(req
));
416 /* Send the setup message */
417 dbgp_set_data(&req
, sizeof(req
));
418 writel(addr
, &ehci_debug
->address
);
419 writel(pids
, &ehci_debug
->pids
);
420 ret
= dbgp_wait_until_done(ctrl
);
424 /* Read the result */
425 return dbgp_bulk_read(devnum
, 0, data
, size
);
429 /* Find a PCI capability */
430 static u32 __init
find_cap(u32 num
, u32 slot
, u32 func
, int cap
)
435 if (!(read_pci_config_16(num
, slot
, func
, PCI_STATUS
) &
436 PCI_STATUS_CAP_LIST
))
439 pos
= read_pci_config_byte(num
, slot
, func
, PCI_CAPABILITY_LIST
);
440 for (bytes
= 0; bytes
< 48 && pos
>= 0x40; bytes
++) {
444 id
= read_pci_config_byte(num
, slot
, func
, pos
+PCI_CAP_LIST_ID
);
450 pos
= read_pci_config_byte(num
, slot
, func
,
451 pos
+PCI_CAP_LIST_NEXT
);
456 static u32 __init
__find_dbgp(u32 bus
, u32 slot
, u32 func
)
460 class = read_pci_config(bus
, slot
, func
, PCI_CLASS_REVISION
);
461 if ((class >> 8) != PCI_CLASS_SERIAL_USB_EHCI
)
464 return find_cap(bus
, slot
, func
, PCI_CAP_ID_EHCI_DEBUG
);
467 static u32 __init
find_dbgp(int ehci_num
, u32
*rbus
, u32
*rslot
, u32
*rfunc
)
471 for (bus
= 0; bus
< 256; bus
++) {
472 for (slot
= 0; slot
< 32; slot
++) {
473 for (func
= 0; func
< 8; func
++) {
476 cap
= __find_dbgp(bus
, slot
, func
);
492 static int __init
ehci_reset_port(int port
)
495 u32 delay_time
, delay
;
498 /* Reset the usb debug port */
499 portsc
= readl(&ehci_regs
->port_status
[port
- 1]);
501 portsc
|= PORT_RESET
;
502 writel(portsc
, &ehci_regs
->port_status
[port
- 1]);
504 delay
= HUB_ROOT_RESET_TIME
;
505 for (delay_time
= 0; delay_time
< HUB_RESET_TIMEOUT
;
506 delay_time
+= delay
) {
509 portsc
= readl(&ehci_regs
->port_status
[port
- 1]);
510 if (portsc
& PORT_RESET
) {
511 /* force reset to complete */
513 writel(portsc
& ~(PORT_RWC_BITS
| PORT_RESET
),
514 &ehci_regs
->port_status
[port
- 1]);
516 portsc
= readl(&ehci_regs
->port_status
[port
-1]);
517 } while ((portsc
& PORT_RESET
) && (--loop
> 0));
520 /* Device went away? */
521 if (!(portsc
& PORT_CONNECT
))
524 /* bomb out completely if something weird happend */
525 if ((portsc
& PORT_CSC
))
528 /* If we've finished resetting, then break out of the loop */
529 if (!(portsc
& PORT_RESET
) && (portsc
& PORT_PE
))
535 static int __init
ehci_wait_for_port(int port
)
540 for (reps
= 0; reps
< 3; reps
++) {
542 status
= readl(&ehci_regs
->status
);
543 if (status
& STS_PCD
) {
544 ret
= ehci_reset_port(port
);
553 # define dbgp_printk early_printk
555 static inline void dbgp_printk(const char *fmt
, ...) { }
558 typedef void (*set_debug_port_t
)(int port
);
560 static void __init
default_set_debug_port(int port
)
564 static set_debug_port_t __initdata set_debug_port
= default_set_debug_port
;
566 static void __init
nvidia_set_debug_port(int port
)
569 dword
= read_pci_config(ehci_dev
.bus
, ehci_dev
.slot
, ehci_dev
.func
,
571 dword
&= ~(0x0f<<12);
572 dword
|= ((port
& 0x0f)<<12);
573 write_pci_config(ehci_dev
.bus
, ehci_dev
.slot
, ehci_dev
.func
, 0x74,
575 dbgp_printk("set debug port to %d\n", port
);
578 static void __init
detect_set_debug_port(void)
582 vendorid
= read_pci_config(ehci_dev
.bus
, ehci_dev
.slot
, ehci_dev
.func
,
585 if ((vendorid
& 0xffff) == 0x10de) {
586 dbgp_printk("using nvidia set_debug_port\n");
587 set_debug_port
= nvidia_set_debug_port
;
591 static int __init
ehci_setup(void)
593 struct usb_debug_descriptor dbgp_desc
;
594 u32 cmd
, ctrl
, status
, portsc
, hcs_params
;
595 u32 debug_port
, new_debug_port
= 0, n_ports
;
607 hcs_params
= readl(&ehci_caps
->hcs_params
);
608 debug_port
= HCS_DEBUG_PORT(hcs_params
);
609 n_ports
= HCS_N_PORTS(hcs_params
);
611 dbgp_printk("debug_port: %d\n", debug_port
);
612 dbgp_printk("n_ports: %d\n", n_ports
);
614 for (i
= 1; i
<= n_ports
; i
++) {
615 portsc
= readl(&ehci_regs
->port_status
[i
-1]);
616 dbgp_printk("portstatus%d: %08x\n", i
, portsc
);
619 if (port_map_tried
&& (new_debug_port
!= debug_port
)) {
621 set_debug_port(new_debug_port
);
628 /* Reset the EHCI controller */
629 cmd
= readl(&ehci_regs
->command
);
631 writel(cmd
, &ehci_regs
->command
);
633 cmd
= readl(&ehci_regs
->command
);
634 } while ((cmd
& CMD_RESET
) && (--loop
> 0));
637 dbgp_printk("can not reset ehci\n");
640 dbgp_printk("ehci reset done\n");
642 /* Claim ownership, but do not enable yet */
643 ctrl
= readl(&ehci_debug
->control
);
645 ctrl
&= ~(DBGP_ENABLED
| DBGP_INUSE
);
646 writel(ctrl
, &ehci_debug
->control
);
648 /* Start the ehci running */
649 cmd
= readl(&ehci_regs
->command
);
650 cmd
&= ~(CMD_LRESET
| CMD_IAAD
| CMD_PSE
| CMD_ASE
| CMD_RESET
);
652 writel(cmd
, &ehci_regs
->command
);
654 /* Ensure everything is routed to the EHCI */
655 writel(FLAG_CF
, &ehci_regs
->configured_flag
);
657 /* Wait until the controller is no longer halted */
660 status
= readl(&ehci_regs
->status
);
661 } while ((status
& STS_HALT
) && (--loop
> 0));
664 dbgp_printk("ehci can be started\n");
667 dbgp_printk("ehci started\n");
669 /* Wait for a device to show up in the debug port */
670 ret
= ehci_wait_for_port(debug_port
);
672 dbgp_printk("No device found in debug port\n");
673 goto next_debug_port
;
675 dbgp_printk("ehci wait for port done\n");
677 /* Enable the debug port */
678 ctrl
= readl(&ehci_debug
->control
);
680 writel(ctrl
, &ehci_debug
->control
);
681 ctrl
= readl(&ehci_debug
->control
);
682 if ((ctrl
& DBGP_CLAIM
) != DBGP_CLAIM
) {
683 dbgp_printk("No device in debug port\n");
684 writel(ctrl
& ~DBGP_CLAIM
, &ehci_debug
->control
);
687 dbgp_printk("debug ported enabled\n");
689 /* Completely transfer the debug device to the debug controller */
690 portsc
= readl(&ehci_regs
->port_status
[debug_port
- 1]);
692 writel(portsc
, &ehci_regs
->port_status
[debug_port
- 1]);
696 /* Find the debug device and make it device number 127 */
697 for (devnum
= 0; devnum
<= 127; devnum
++) {
698 ret
= dbgp_control_msg(devnum
,
699 USB_DIR_IN
| USB_TYPE_STANDARD
| USB_RECIP_DEVICE
,
700 USB_REQ_GET_DESCRIPTOR
, (USB_DT_DEBUG
<< 8), 0,
701 &dbgp_desc
, sizeof(dbgp_desc
));
706 dbgp_printk("Could not find attached debug device\n");
710 dbgp_printk("Attached device is not a debug device\n");
713 dbgp_endpoint_out
= dbgp_desc
.bDebugOutEndpoint
;
715 /* Move the device to 127 if it isn't already there */
716 if (devnum
!= USB_DEBUG_DEVNUM
) {
717 ret
= dbgp_control_msg(devnum
,
718 USB_DIR_OUT
| USB_TYPE_STANDARD
| USB_RECIP_DEVICE
,
719 USB_REQ_SET_ADDRESS
, USB_DEBUG_DEVNUM
, 0, NULL
, 0);
721 dbgp_printk("Could not move attached device to %d\n",
725 devnum
= USB_DEBUG_DEVNUM
;
726 dbgp_printk("debug device renamed to 127\n");
729 /* Enable the debug interface */
730 ret
= dbgp_control_msg(USB_DEBUG_DEVNUM
,
731 USB_DIR_OUT
| USB_TYPE_STANDARD
| USB_RECIP_DEVICE
,
732 USB_REQ_SET_FEATURE
, USB_DEVICE_DEBUG_MODE
, 0, NULL
, 0);
734 dbgp_printk(" Could not enable the debug device\n");
737 dbgp_printk("debug interface enabled\n");
739 /* Perform a small write to get the even/odd data state in sync
741 ret
= dbgp_bulk_write(USB_DEBUG_DEVNUM
, dbgp_endpoint_out
, " ", 1);
743 dbgp_printk("dbgp_bulk_write failed: %d\n", ret
);
746 dbgp_printk("small write doned\n");
750 /* Things didn't work so remove my claim */
751 ctrl
= readl(&ehci_debug
->control
);
752 ctrl
&= ~(DBGP_CLAIM
| DBGP_OUT
);
753 writel(ctrl
, &ehci_debug
->control
);
757 port_map_tried
|= (1<<(debug_port
- 1));
758 new_debug_port
= ((debug_port
-1+1)%n_ports
) + 1;
759 if (port_map_tried
!= ((1<<n_ports
) - 1)) {
760 set_debug_port(new_debug_port
);
764 set_debug_port(new_debug_port
);
771 static int __init
early_dbgp_init(char *s
)
773 u32 debug_port
, bar
, offset
;
774 u32 bus
, slot
, func
, cap
;
775 void __iomem
*ehci_bar
;
782 if (!early_pci_allowed())
787 dbgp_num
= simple_strtoul(s
, &e
, 10);
788 dbgp_printk("dbgp_num: %d\n", dbgp_num
);
790 cap
= find_dbgp(dbgp_num
, &bus
, &slot
, &func
);
794 dbgp_printk("Found EHCI debug port on %02x:%02x.%1x\n", bus
, slot
,
797 debug_port
= read_pci_config(bus
, slot
, func
, cap
);
798 bar
= (debug_port
>> 29) & 0x7;
799 bar
= (bar
* 4) + 0xc;
800 offset
= (debug_port
>> 16) & 0xfff;
801 dbgp_printk("bar: %02x offset: %03x\n", bar
, offset
);
802 if (bar
!= PCI_BASE_ADDRESS_0
) {
803 dbgp_printk("only debug ports on bar 1 handled.\n");
808 bar_val
= read_pci_config(bus
, slot
, func
, PCI_BASE_ADDRESS_0
);
809 dbgp_printk("bar_val: %02x offset: %03x\n", bar_val
, offset
);
810 if (bar_val
& ~PCI_BASE_ADDRESS_MEM_MASK
) {
811 dbgp_printk("only simple 32bit mmio bars supported\n");
816 /* double check if the mem space is enabled */
817 byte
= read_pci_config_byte(bus
, slot
, func
, 0x04);
820 write_pci_config_byte(bus
, slot
, func
, 0x04, byte
);
821 dbgp_printk("mmio for ehci enabled\n");
825 * FIXME I don't have the bar size so just guess PAGE_SIZE is more
826 * than enough. 1K is the biggest I have seen.
828 set_fixmap_nocache(FIX_DBGP_BASE
, bar_val
& PAGE_MASK
);
829 ehci_bar
= (void __iomem
*)__fix_to_virt(FIX_DBGP_BASE
);
830 ehci_bar
+= bar_val
& ~PAGE_MASK
;
831 dbgp_printk("ehci_bar: %p\n", ehci_bar
);
833 ehci_caps
= ehci_bar
;
834 ehci_regs
= ehci_bar
+ HC_LENGTH(readl(&ehci_caps
->hc_capbase
));
835 ehci_debug
= ehci_bar
+ offset
;
837 ehci_dev
.slot
= slot
;
838 ehci_dev
.func
= func
;
840 detect_set_debug_port();
844 dbgp_printk("ehci_setup failed\n");
853 static void early_dbgp_write(struct console
*con
, const char *str
, u32 n
)
861 if (chunk
> DBGP_MAX_PACKET
)
862 chunk
= DBGP_MAX_PACKET
;
863 ret
= dbgp_bulk_write(USB_DEBUG_DEVNUM
,
864 dbgp_endpoint_out
, str
, chunk
);
870 static struct console early_dbgp_console
= {
872 .write
= early_dbgp_write
,
873 .flags
= CON_PRINTBUFFER
,
878 /* Direct interface for emergencies */
879 static struct console
*early_console
= &early_vga_console
;
880 static int __initdata early_console_initialized
;
882 asmlinkage
void early_printk(const char *fmt
, ...)
889 n
= vscnprintf(buf
, sizeof(buf
), fmt
, ap
);
890 early_console
->write(early_console
, buf
, n
);
895 static int __init
setup_early_printk(char *buf
)
902 if (early_console_initialized
)
904 early_console_initialized
= 1;
906 keep_early
= (strstr(buf
, "keep") != NULL
);
908 if (!strncmp(buf
, "serial", 6)) {
909 early_serial_init(buf
+ 6);
910 early_console
= &early_serial_console
;
911 } else if (!strncmp(buf
, "ttyS", 4)) {
912 early_serial_init(buf
);
913 early_console
= &early_serial_console
;
914 } else if (!strncmp(buf
, "vga", 3)
915 && boot_params
.screen_info
.orig_video_isVGA
== 1) {
916 max_xpos
= boot_params
.screen_info
.orig_video_cols
;
917 max_ypos
= boot_params
.screen_info
.orig_video_lines
;
918 current_ypos
= boot_params
.screen_info
.orig_y
;
919 early_console
= &early_vga_console
;
920 #ifdef CONFIG_EARLY_PRINTK_DBGP
921 } else if (!strncmp(buf
, "dbgp", 4)) {
922 if (early_dbgp_init(buf
+4) < 0)
924 early_console
= &early_dbgp_console
;
926 * usb subsys will reset ehci controller, so don't keep
931 #ifdef CONFIG_HVC_XEN
932 } else if (!strncmp(buf
, "xen", 3)) {
933 early_console
= &xenboot_console
;
938 early_console
->flags
&= ~CON_BOOT
;
940 early_console
->flags
|= CON_BOOT
;
941 register_console(early_console
);
945 early_param("earlyprintk", setup_early_printk
);