aboutsummaryrefslogtreecommitdiff
path: root/arch/cris/kernel/setup.c
blob: 6ec2671078bf4a3f5b27d92f79eec0aab4f2a2c1 (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
192
193
/*
 *
 *  linux/arch/cris/kernel/setup.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *  Copyright (c) 2001  Axis Communications AB
 */

/*
 * This file handles the architecture-dependent parts of initialization
 */

#include <linux/config.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <asm/pgtable.h>
#include <linux/seq_file.h>
#include <linux/tty.h>

#include <asm/setup.h>

/*
 * Setup options
 */
struct drive_info_struct { char dummy[32]; } drive_info;
struct screen_info screen_info;

extern int root_mountflags;
extern char _etext, _edata, _end;

static char command_line[COMMAND_LINE_SIZE] = { 0, };

extern const unsigned long text_start, edata; /* set by the linker script */
extern unsigned long dram_start, dram_end;

extern unsigned long romfs_start, romfs_length, romfs_in_flash; /* from head.S */

extern void show_etrax_copyright(void);		/* arch-vX/kernel/setup.c */

/* This mainly sets up the memory area, and can be really confusing.
 *
 * The physical DRAM is virtually mapped into dram_start to dram_end
 * (usually c0000000 to c0000000 + DRAM size). The physical address is
 * given by the macro __pa().
 *
 * In this DRAM, the kernel code and data is loaded, in the beginning.
 * It really starts at c0004000 to make room for some special pages - 
 * the start address is text_start. The kernel data ends at _end. After
 * this the ROM filesystem is appended (if there is any).
 * 
 * Between this address and dram_end, we have RAM pages usable to the
 * boot code and the system.
 *
 */

void __init 
setup_arch(char **cmdline_p)
{
	extern void init_etrax_debug(void);
	unsigned long bootmap_size;
	unsigned long start_pfn, max_pfn;
	unsigned long memory_start;

 	/* register an initial console printing routine for printk's */

	init_etrax_debug();

	/* we should really poll for DRAM size! */

	high_memory = &dram_end;

	if(romfs_in_flash || !romfs_length) {
		/* if we have the romfs in flash, or if there is no rom filesystem,
		 * our free area starts directly after the BSS
		 */
		memory_start = (unsigned long) &_end;
	} else {
		/* otherwise the free area starts after the ROM filesystem */
		printk("ROM fs in RAM, size %lu bytes\n", romfs_length);
		memory_start = romfs_start + romfs_length;
	}

	/* process 1's initial memory region is the kernel code/data */

	init_mm.start_code = (unsigned long) &text_start;
	init_mm.end_code =   (unsigned long) &_etext;
	init_mm.end_data =   (unsigned long) &_edata;
	init_mm.brk =        (unsigned long) &_end;

#define PFN_UP(x)       (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
#define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
#define PFN_PHYS(x)     ((x) << PAGE_SHIFT)

	/* min_low_pfn points to the start of DRAM, start_pfn points
	 * to the first DRAM pages after the kernel, and max_low_pfn
	 * to the end of DRAM.
	 */

        /*
         * partially used pages are not usable - thus
         * we are rounding upwards:
         */

        start_pfn = PFN_UP(memory_start);  /* usually c0000000 + kernel + romfs */
	max_pfn =   PFN_DOWN((unsigned long)high_memory); /* usually c0000000 + dram size */

        /*
         * Initialize the boot-time allocator (start, end)
	 *
	 * We give it access to all our DRAM, but we could as well just have
	 * given it a small slice. No point in doing that though, unless we
	 * have non-contiguous memory and want the boot-stuff to be in, say,
	 * the smallest area.
	 *
	 * It will put a bitmap of the allocated pages in the beginning
	 * of the range we give it, but it won't mark the bitmaps pages
	 * as reserved. We have to do that ourselves below.
	 *
	 * We need to use init_bootmem_node instead of init_bootmem
	 * because our map starts at a quite high address (min_low_pfn).
         */

	max_low_pfn = max_pfn;
	min_low_pfn = PAGE_OFFSET >> PAGE_SHIFT;

	bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
					 min_low_pfn, 
					 max_low_pfn);

	/* And free all memory not belonging to the kernel (addr, size) */

	free_bootmem(PFN_PHYS(start_pfn), PFN_PHYS(max_pfn - start_pfn));

        /*
         * Reserve the bootmem bitmap itself as well. We do this in two
         * steps (first step was init_bootmem()) because this catches
         * the (very unlikely) case of us accidentally initializing the
         * bootmem allocator with an invalid RAM area.
	 *
	 * Arguments are start, size
         */

        reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size);

	/* paging_init() sets up the MMU and marks all pages as reserved */

	paging_init();

	/* We don't use a command line yet, so just re-initialize it without
	   saving anything that might be there.  */

	*cmdline_p = command_line;

#ifdef CONFIG_ETRAX_CMDLINE
	strlcpy(command_line, CONFIG_ETRAX_CMDLINE, COMMAND_LINE_SIZE);
	command_line[COMMAND_LINE_SIZE - 1] = '\0';

	/* Save command line for future references. */
	memcpy(saved_command_line, command_line, COMMAND_LINE_SIZE);
	saved_command_line[COMMAND_LINE_SIZE - 1] = '\0';
#endif

	/* give credit for the CRIS port */
	show_etrax_copyright();
}

static void *c_start(struct seq_file *m, loff_t *pos)
{
	/* We only got one CPU... */
	return *pos < 1 ? (void *)1 : NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
	++*pos;
	return NULL;
}

static void c_stop(struct seq_file *m, void *v)
{
}

extern int show_cpuinfo(struct seq_file *m, void *v);

struct seq_operations cpuinfo_op = {
	.start = c_start,
	.next  = c_next,
	.stop  = c_stop,
	.show  = show_cpuinfo,
};