summaryrefslogtreecommitdiff
path: root/arch/alpha/boot/main.c
blob: 644b7db55438f4f1d1b8136bd9f680bbcf4f75a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
/*
 * arch/alpha/boot/main.c
 *
 * Copyright (C) 1994, 1995 Linus Torvalds
 *
 * This file is the bootloader for the Linux/AXP kernel
 */
#include <linux/kernel.h>
#include <linux/string.h>
#include <generated/utsrelease.h>
#include <linux/mm.h>

#include <asm/system.h>
#include <asm/console.h>
#include <asm/hwrpb.h>
#include <asm/pgtable.h>

#include <stdarg.h>

#include "ksize.h"

extern int vsprintf(char *, const char *, va_list);
extern unsigned long switch_to_osf_pal(unsigned long nr,
	struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,
	unsigned long *vptb);
struct hwrpb_struct *hwrpb = INIT_HWRPB;
static struct pcb_struct pcb_va[1];

/*
 * Find a physical address of a virtual object..
 *
 * This is easy using the virtual page table address.
 */

static inline void *
find_pa(unsigned long *vptb, void *ptr)
{
	unsigned long address = (unsigned long) ptr;
	unsigned long result;

	result = vptb[address >> 13];
	result >>= 32;
	result <<= 13;
	result |= address & 0x1fff;
	return (void *) result;
}	

/*
 * This function moves into OSF/1 pal-code, and has a temporary
 * PCB for that. The kernel proper should replace this PCB with
 * the real one as soon as possible.
 *
 * The page table muckery in here depends on the fact that the boot
 * code has the L1 page table identity-map itself in the second PTE
 * in the L1 page table. Thus the L1-page is virtually addressable
 * itself (through three levels) at virtual address 0x200802000.
 */

#define VPTB	((unsigned long *) 0x200000000)
#define L1	((unsigned long *) 0x200802000)

void
pal_init(void)
{
	unsigned long i, rev;
	struct percpu_struct * percpu;
	struct pcb_struct * pcb_pa;

	/* Create the dummy PCB.  */
	pcb_va->ksp = 0;
	pcb_va->usp = 0;
	pcb_va->ptbr = L1[1] >> 32;
	pcb_va->asn = 0;
	pcb_va->pcc = 0;
	pcb_va->unique = 0;
	pcb_va->flags = 1;
	pcb_va->res1 = 0;
	pcb_va->res2 = 0;
	pcb_pa = find_pa(VPTB, pcb_va);

	/*
	 * a0 = 2 (OSF)
	 * a1 = return address, but we give the asm the vaddr of the PCB
	 * a2 = physical addr of PCB
	 * a3 = new virtual page table pointer
	 * a4 = KSP (but the asm sets it)
	 */
	srm_printk("Switching to OSF PAL-code .. ");

	i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB);
	if (i) {
		srm_printk("failed, code %ld\n", i);
		__halt();
	}

	percpu = (struct percpu_struct *)
		(INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB);
	rev = percpu->pal_revision = percpu->palcode_avail[2];

	srm_printk("Ok (rev %lx)\n", rev);

	tbia(); /* do it directly in case we are SMP */
}

static inline long openboot(void)
{
	char bootdev[256];
	long result;

	result = callback_getenv(ENV_BOOTED_DEV, bootdev, 255);
	if (result < 0)
		return result;
	return callback_open(bootdev, result & 255);
}

static inline long close(long dev)
{
	return callback_close(dev);
}

static inline long load(long dev, unsigned long addr, unsigned long count)
{
	char bootfile[256];
	extern char _end;
	long result, boot_size = &_end - (char *) BOOT_ADDR;

	result = callback_getenv(ENV_BOOTED_FILE, bootfile, 255);
	if (result < 0)
		return result;
	result &= 255;
	bootfile[result] = '\0';
	if (result)
		srm_printk("Boot file specification (%s) not implemented\n",
		       bootfile);
	return callback_read(dev, count, (void *)addr, boot_size/512 + 1);
}

/*
 * Start the kernel.
 */
static void runkernel(void)
{
	__asm__ __volatile__(
		"bis %1,%1,$30\n\t"
		"bis %0,%0,$26\n\t"
		"ret ($26)"
		: /* no outputs: it doesn't even return */
		: "r" (START_ADDR),
		  "r" (PAGE_SIZE + INIT_STACK));
}

void start_kernel(void)
{
	long i;
	long dev;
	int nbytes;
	char envval[256];

	srm_printk("Linux/AXP bootloader for Linux " UTS_RELEASE "\n");
	if (INIT_HWRPB->pagesize != 8192) {
		srm_printk("Expected 8kB pages, got %ldkB\n", INIT_HWRPB->pagesize >> 10);
		return;
	}
	pal_init();
	dev = openboot();
	if (dev < 0) {
		srm_printk("Unable to open boot device: %016lx\n", dev);
		return;
	}
	dev &= 0xffffffff;
	srm_printk("Loading vmlinux ...");
	i = load(dev, START_ADDR, KERNEL_SIZE);
	close(dev);
	if (i != KERNEL_SIZE) {
		srm_printk("Failed (%lx)\n", i);
		return;
	}

	nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval));
	if (nbytes < 0) {
		nbytes = 0;
	}
	envval[nbytes] = '\0';
	strcpy((char*)ZERO_PGE, envval);

	srm_printk(" Ok\nNow booting the kernel\n");
	runkernel();
	for (i = 0 ; i < 0x100000000 ; i++)
		/* nothing */;
	__halt();
}