arch/mips/dec/boot/decstation.c

   1 /*
   2  * arch/mips/dec/decstation.c
   3  */
   4
   5 #define RELOC
   6 #define INITRD
   7 #define DEBUG_BOOT
   8
   9 /*
  10  * Magic number indicating REX PROM available on DECSTATION.
  11  */
  12 #define REX_PROM_MAGIC          0x30464354
  13
  14 #define REX_PROM_CLEARCACHE     0x7c/4
  15 #define REX_PROM_PRINTF         0x30/4
  16
  17 #define VEC_RESET               0xBFC00000              /* Prom base address */
  18 #define PMAX_PROM_ENTRY(x)      (VEC_RESET+((x)*8))     /* Prom jump table */
  19 #define PMAX_PROM_PRINTF        PMAX_PROM_ENTRY(17)
  20
  21 #define PARAM   (k_start + 0x2000)
  22
  23 #define LOADER_TYPE (*(unsigned char *) (PARAM+0x210))
  24 #define INITRD_START (*(unsigned long *) (PARAM+0x218))
  25 #define INITRD_SIZE (*(unsigned long *) (PARAM+0x21c))
  26
  27 extern int _ftext, _end;                /* begin and end of kernel image */
  28 extern void kernel_entry(int, char **, unsigned long, int *);
  29
  30 void * memcpy(void * dest, const void *src, unsigned int count)
  31 {
  32         unsigned long *tmp = (unsigned long *) dest, *s = (unsigned long *) src;
  33
  34         count >>= 2;
  35         while (count--)
  36                 *tmp++ = *s++;
  37
  38         return dest;
  39 }
  40
  41 void dec_entry(int argc, char **argv,
  42                unsigned long magic, int *prom_vec)
  43 {
  44         void (*rex_clear_cache)(void);
  45         int (*prom_printf)(char *, ...);
  46         unsigned long k_start, len;
  47
  48         /*
  49          * The DS5100 leaves cpu with BEV enabled, clear it.
  50          */
  51         asm(    "lui\t$8,0x3000\n\t"
  52                 "mtc0\t$8,$12\n\t"
  53                 ".section\t.sdata\n\t"
  54                 ".section\t.sbss\n\t"
  55                 ".section\t.text"
  56                 : : : "$8");
  57
  58 #ifdef DEBUG_BOOT
  59         if (magic == REX_PROM_MAGIC) {
  60         prom_printf = (int (*)(char *, ...)) *(prom_vec + REX_PROM_PRINTF);
  61         } else {
  62                 prom_printf = (int (*)(char *, ...)) PMAX_PROM_PRINTF;
  63         }
  64         prom_printf("Launching kernel...\n");
  65 #endif
  66
  67         k_start = (unsigned long) (&kernel_entry) & 0xffff0000;
  68
  69 #ifdef RELOC
  70         /*
  71          * Now copy kernel image to its destination.
  72          */
  73         len = ((unsigned long) (&_end) - k_start);
  74         memcpy((void *)k_start, &_ftext, len);
  75 #endif
  76
  77         if (magic == REX_PROM_MAGIC) {
  78                 rex_clear_cache = (void (*)(void)) * (prom_vec + REX_PROM_CLEARCACHE);
  79                 rex_clear_cache();
  80         }
  81
  82         kernel_entry(argc, argv, magic, prom_vec);
  83 }