text: /*
   *  linux/arch/sh/kernel/sh_bios.c
   *  C interface for trapping into the standard LinuxSH BIOS.
   *
   *  Copyright (C) 2000 Greg Banks, Mitch Davis
   *
   */
  #include <linux/module.h>
  #include <asm/sh_bios.h>
  
  #define BIOS_CALL_CONSOLE_WRITE     	0
  #define BIOS_CALL_READ_BLOCK     	1
  #define BIOS_CALL_ETH_NODE_ADDR		10
  #define BIOS_CALL_SHUTDOWN		11
  #define BIOS_CALL_CHAR_OUT     	    	0x1f  	/* TODO: hack */
  #define BIOS_CALL_GDB_GET_MODE_PTR     	0xfe
  #define BIOS_CALL_GDB_DETACH     	0xff
  
  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;
      __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_char_out(char ch)
  {
      sh_bios_call(BIOS_CALL_CHAR_OUT, ch, 0, 0, 0);
  }
  
  
  int sh_bios_in_gdb_mode(void)
  {
      static char queried = 0;
      static char *gdb_mode_p = 0;
  
      if (!queried)
      {
      	/* Query the gdb stub for address of its gdb mode variable */
      	long r = sh_bios_call(BIOS_CALL_GDB_GET_MODE_PTR, 0, 0, 0, 0);
  	if (r != ~0)	/* BIOS returns -1 for unknown function */
  	    gdb_mode_p = (char *)r;
  	queried = 1;
      }
      return (gdb_mode_p != 0 ? *gdb_mode_p : 0);
  }
  
  void sh_bios_gdb_detach(void)
  {
      sh_bios_call(BIOS_CALL_GDB_DETACH, 0, 0, 0, 0);
  }
  EXPORT_SYMBOL(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);
  }
  
  void sh_bios_shutdown(unsigned int how)
  {
      sh_bios_call(BIOS_CALL_SHUTDOWN, how, 0, 0, 0);
  }
  