/*
* C interface for trapping into the standard LinuxSH BIOS.
*
* Copyright (C) 2000 Greg Banks, Mitch Davis
* Copyright (C) 1999, 2000 Niibe Yutaka
* Copyright (C) 2002 M. R. Brown
* Copyright (C) 2004 - 2010 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <asm/sh_bios.h>
#define BIOS_CALL_CONSOLE_WRITE 0
#define BIOS_CALL_ETH_NODE_ADDR 10
#define BIOS_CALL_SHUTDOWN 11
#define BIOS_CALL_GDB_DETACH 0xff
void *gdb_vbr_vector = NULL;
static inline long sh_bios_call(long func, long arg0, long arg1, long arg2,
long arg3)
{
register long r0 __asm__("r0") = func;
register long r4 __asm__("r4") = arg0;
register long r5 __asm__("r5") = arg1;
register long r6 __asm__("r6") = arg2;
register long r7 __asm__("r7") = arg3;
if (!gdb_vbr_vector)
return -ENOSYS;
__asm__ __volatile__("trapa #0x3f":"=z"(r0)
:"0"(r0), "r"(r4), "r"(r5), "r"(r6), "r"(r7)
:"memory");
return r0;
}
void sh_bios_console_write(const char *buf, unsigned int len)
{
sh_bios_call(BIOS_CALL_CONSOLE_WRITE, (long)buf, (long)len, 0, 0);
}
void sh_bios_gdb_detach(void)
{
sh_bios_call(BIOS_CALL_GDB_DETACH, 0, 0, 0, 0);
}
EXPORT_SYMBOL_GPL(sh_bios_gdb_detach);
void sh_bios_get_node_addr(unsigned char *node_addr)
{
sh_bios_call(BIOS_CALL_ETH_NODE_ADDR, 0, (long)node_addr, 0, 0);
}
EXPORT_SYMBOL_GPL(sh_bios_get_node_addr);
void sh_bios_shutdown(unsigned int how)
{
sh_bios_call(BIOS_CALL_SHUTDOWN, how, 0, 0, 0);
}
/*
* Read the old value of the VBR register to initialise the vector
* through which debug and BIOS traps are delegated by the Linux trap
* handler.
*/
void sh_bios_vbr_init(void)
{
unsigned long vbr;
if (unlikely(gdb_vbr_vector))
return;
__asm__ __volatile__ ("stc vbr, %0" : "=r" (vbr));
if (vbr) {
gdb_vbr_vector = (void *)(vbr + 0x100);
printk(KERN_NOTICE "Setting GDB trap vector to %p\n",
gdb_vbr_vector);
} else
printk(KERN_NOTICE "SH-BIOS not detected\n");
}
/**
* sh_bios_vbr_reload - Re-load the system VBR from the BIOS vector.
*
* This can be used by save/restore code to reinitialize the system VBR
* from the fixed BIOS VBR. A no-op if no BIOS VBR is known.
*/
void sh_bios_vbr_reload(void)
{
if (gdb_vbr_vector)
__asm__ __volatile__ (
"ldc %0, vbr"
:
: "r" (((unsigned long) gdb_vbr_vector) - 0x100)
: "memory"
);
}
#ifdef CONFIG_EARLY_PRINTK
/*
* Print a string through the BIOS
*/
static void sh_console_write(struct console *co, const char *s,
unsigned count)
{
sh_bios_console_write(s, count);
}
/*
* Setup initial baud/bits/parity. We do two things here:
* - construct a cflag setting for the first rs_open()
* - initialize the serial port
* Return non-zero if we didn't find a serial port.
*/
static int __init sh_console_setup(struct console *co, char *options)
{
int cflag = CREAD | HUPCL | CLOCAL;
/*
* Now construct a cflag setting.
* TODO: this is a totally bogus cflag, as we have
* no idea what serial settings the BIOS is using, or
* even if its using the serial port at all.
*/
cflag |= B115200 | CS8 | /*no parity*/0;
co->cflag = cflag;
return 0;
}
static struct console bios_console = {
.name = "bios",
.write = sh_console_write,
.setup = sh_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
static int __init setup_early_printk(char *buf)
{
int keep_early = 0;
if (!buf)
return 0;
if (strstr(buf, "keep"))
keep_early = 1;
if (!strncmp(buf, "bios", 4))
early_console = &bios_console;
if (likely(early_console)) {
if (keep_early)
early_console->flags &= ~CON_BOOT;
else
early_console->flags |= CON_BOOT;
register_console(early_console);
}
return 0;
}
early_param("earlyprintk", setup_early_printk);
#endif
