arch/sh/kernel/sh_bios.c

   1 /*
   2  *  linux/arch/sh/kernel/sh_bios.c
   3  *  C interface for trapping into the standard LinuxSH BIOS.
   4  *
   5  *  Copyright (C) 2000 Greg Banks, Mitch Davis
   6  *
   7  */
   8
   9 #include <asm/sh_bios.h>
  10
  11 #define BIOS_CALL_CONSOLE_WRITE         0
  12 #define BIOS_CALL_READ_BLOCK            1
  13 #define BIOS_CALL_ETH_NODE_ADDR         10
  14 #define BIOS_CALL_SHUTDOWN              11
  15 #define BIOS_CALL_CHAR_OUT              0x1f    /* TODO: hack */
  16 #define BIOS_CALL_GDB_GET_MODE_PTR      0xfe
  17 #define BIOS_CALL_GDB_DETACH            0xff
  18
  19 static __inline__ long sh_bios_call(long func, long arg0, long arg1, long arg2, long arg3)
  20 {
  21     register long r0 __asm__("r0") = func;
  22     register long r4 __asm__("r4") = arg0;
  23     register long r5 __asm__("r5") = arg1;
  24     register long r6 __asm__("r6") = arg2;
  25     register long r7 __asm__("r7") = arg3;
  26     __asm__ __volatile__("trapa #0x3f"
  27          : "=z" (r0)
  28          : "0" (r0), "r" (r4), "r" (r5), "r" (r6), "r" (r7)
  29          : "memory");
  30     return r0;
  31 }
  32
  33
  34 void sh_bios_console_write(const char *buf, unsigned int len)
  35 {
  36     sh_bios_call(BIOS_CALL_CONSOLE_WRITE, (long)buf, (long)len, 0, 0);
  37 }
  38
  39
  40 void sh_bios_char_out(char ch)
  41 {
  42     sh_bios_call(BIOS_CALL_CHAR_OUT, ch, 0, 0, 0);
  43 }
  44
  45
  46 int sh_bios_in_gdb_mode(void)
  47 {
  48     static char queried = 0;
  49     static char *gdb_mode_p = 0;
  50
  51     if (!queried)
  52     {
  53         /* Query the gdb stub for address of its gdb mode variable */
  54         long r = sh_bios_call(BIOS_CALL_GDB_GET_MODE_PTR, 0, 0, 0, 0);
  55         if (r != ~0)    /* BIOS returns -1 for unknown function */
  56             gdb_mode_p = (char *)r;
  57         queried = 1;
  58     }
  59     return (gdb_mode_p != 0 ? *gdb_mode_p : 0);
  60 }
  61
  62 void sh_bios_gdb_detach(void)
  63 {
  64     sh_bios_call(BIOS_CALL_GDB_DETACH, 0, 0, 0, 0);
  65 }
  66
  67 void sh_bios_get_node_addr (unsigned char *node_addr)
  68 {
  69     sh_bios_call(BIOS_CALL_ETH_NODE_ADDR, 0, (long)node_addr, 0, 0);
  70 }
  71
  72 void sh_bios_shutdown(unsigned int how)
  73 {
  74     sh_bios_call(BIOS_CALL_SHUTDOWN, how, 0, 0, 0);
  75 }