File: /usr/src/linux/arch/mips/dec/boot/decstation.c

1     /*
2      * arch/mips/dec/decstation.c
3      */
4     #include <linux/config.h>
5     
6     #define RELOC
7     #define INITRD
8     #define DEBUG_BOOT
9     
10     /*
11      * Magic number indicating REX PROM available on DECSTATION.
12      */
13     #define	REX_PROM_MAGIC		0x30464354
14     
15     #define REX_PROM_CLEARCACHE	0x7c/4
16     #define REX_PROM_PRINTF		0x30/4
17     
18     #define VEC_RESET		0xBFC00000		/* Prom base address */
19     #define	PMAX_PROM_ENTRY(x)	(VEC_RESET+((x)*8))	/* Prom jump table */
20     #define	PMAX_PROM_PRINTF	PMAX_PROM_ENTRY(17)
21     
22     #define PARAM	(k_start + 0x2000)
23     
24     #define LOADER_TYPE (*(unsigned char *) (PARAM+0x210))
25     #define INITRD_START (*(unsigned long *) (PARAM+0x218))
26     #define INITRD_SIZE (*(unsigned long *) (PARAM+0x21c))
27     
28     extern int _ftext, _end;		/* begin and end of kernel image */
29     extern void *__rd_start, *__rd_end;	/* begin and end of ramdisk image */
30     extern void kernel_entry(int, char **, unsigned long, int *);
31     
32     void * memcpy(void * dest, const void *src, unsigned int count)
33     {
34     	unsigned long *tmp = (unsigned long *) dest, *s = (unsigned long *) src;
35     
36     	count >>= 2;
37     	while (count--)
38     		*tmp++ = *s++;
39     
40     	return dest;
41     }
42     
43     void dec_entry(int argc, char **argv,
44     	       unsigned long magic, int *prom_vec)
45     {
46     	void (*rex_clear_cache)(void);
47     	int (*prom_printf)(char *, ...);
48     	unsigned long k_start, len;
49     
50     	/*
51     	 * The DS5100 leaves cpu with BEV enabled, clear it.
52     	 */
53     	asm(	"lui\t$8,0x3000\n\t"
54     		"mtc0\t$8,$12\n\t"
55     		".section\t.sdata\n\t"
56     		".section\t.sbss\n\t"
57     		".section\t.text"
58     		: : : "$8");
59     
60     #ifdef DEBUG_BOOT
61     	if (magic == REX_PROM_MAGIC) {
62     	prom_printf = (int (*)(char *, ...)) *(prom_vec + REX_PROM_PRINTF);
63     	} else {
64     		prom_printf = (int (*)(char *, ...)) PMAX_PROM_PRINTF;
65     	}
66     	prom_printf("Launching kernel...\n");
67     #endif
68     
69     	k_start = (unsigned long) (&kernel_entry) & 0xffff0000;
70     
71     #ifdef RELOC
72     	/*
73     	 * Now copy kernel image to it's destination.
74     	 */
75     	len = ((unsigned long) (&_end) - k_start);
76     	memcpy((void *)k_start, &_ftext, len);
77     #endif
78     
79     	if (magic == REX_PROM_MAGIC) {
80     		rex_clear_cache = (void (*)(void)) * (prom_vec + REX_PROM_CLEARCACHE);
81     		rex_clear_cache();
82     	}
83     
84     #ifdef CONFIG_BLK_DEV_INITRD
85     	LOADER_TYPE = 1;
86     	INITRD_START = (long)&__rd_start;
87     	INITRD_SIZE = (long)&__rd_end - (long)&__rd_start;
88     #endif
89     
90     	kernel_entry(argc, argv, magic, prom_vec);
91     }
92