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 #include <linux/module.h>
   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,
  20                                     long arg3)
  21 {
  22         register long r0 __asm__("r0") = func;
  23         register long r4 __asm__("r4") = arg0;
  24         register long r5 __asm__("r5") = arg1;
  25         register long r6 __asm__("r6") = arg2;
  26         register long r7 __asm__("r7") = arg3;
  27
  28         __asm__ __volatile__("trapa     #0x3f":"=z"(r0)
  29                              :"0"(r0), "r"(r4), "r"(r5), "r"(r6), "r"(r7)
  30                              :"memory");
  31         return r0;
  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 void sh_bios_char_out(char ch)
  40 {
  41         sh_bios_call(BIOS_CALL_CHAR_OUT, ch, 0, 0, 0);
  42 }
  43
  44 int sh_bios_in_gdb_mode(void)
  45 {
  46         static char queried = 0;
  47         static char *gdb_mode_p = 0;
  48
  49         if (!queried) {
  50                 /* Query the gdb stub for address of its gdb mode variable */
  51                 long r = sh_bios_call(BIOS_CALL_GDB_GET_MODE_PTR, 0, 0, 0, 0);
  52                 if (r != ~0)    /* BIOS returns -1 for unknown function */
  53                         gdb_mode_p = (char *)r;
  54                 queried = 1;
  55         }
  56         return (gdb_mode_p != 0 ? *gdb_mode_p : 0);
  57 }
  58
  59 void sh_bios_gdb_detach(void)
  60 {
  61         sh_bios_call(BIOS_CALL_GDB_DETACH, 0, 0, 0, 0);
  62 }
  63
  64 EXPORT_SYMBOL(sh_bios_gdb_detach);
  65
  66 void sh_bios_get_node_addr(unsigned char *node_addr)
  67 {
  68         sh_bios_call(BIOS_CALL_ETH_NODE_ADDR, 0, (long)node_addr, 0, 0);
  69 }
  70
  71 void sh_bios_shutdown(unsigned int how)
  72 {
  73         sh_bios_call(BIOS_CALL_SHUTDOWN, how, 0, 0, 0);
  74 }