3 * linux/arch/cris/kernel/setup.c
5 * Copyright (C) 1995 Linus Torvalds
6 * Copyright (c) 2001 Axis Communications AB
10 * This file handles the architecture-dependent parts of initialization
13 #include <linux/config.h>
14 #include <linux/init.h>
16 #include <linux/bootmem.h>
17 #include <asm/pgtable.h>
18 #include <linux/seq_file.h>
19 #include <linux/tty.h>
24 struct drive_info_struct { char dummy[32]; } drive_info;
25 struct screen_info screen_info;
27 unsigned char aux_device_present;
29 extern int root_mountflags;
30 extern char _etext, _edata, _end;
32 #define COMMAND_LINE_SIZE 256
34 static char command_line[COMMAND_LINE_SIZE] = { 0, };
35 char saved_command_line[COMMAND_LINE_SIZE];
37 extern const unsigned long text_start, edata; /* set by the linker script */
38 extern unsigned long dram_start, dram_end;
40 extern unsigned long romfs_start, romfs_length, romfs_in_flash; /* from head.S */
42 extern void show_etrax_copyright(void); /* arch-vX/kernel/setup.c */
44 /* This mainly sets up the memory area, and can be really confusing.
46 * The physical DRAM is virtually mapped into dram_start to dram_end
47 * (usually c0000000 to c0000000 + DRAM size). The physical address is
48 * given by the macro __pa().
50 * In this DRAM, the kernel code and data is loaded, in the beginning.
51 * It really starts at c0004000 to make room for some special pages -
52 * the start address is text_start. The kernel data ends at _end. After
53 * this the ROM filesystem is appended (if there is any).
55 * Between this address and dram_end, we have RAM pages usable to the
56 * boot code and the system.
61 setup_arch(char **cmdline_p)
63 extern void init_etrax_debug(void);
64 unsigned long bootmap_size;
65 unsigned long start_pfn, max_pfn;
66 unsigned long memory_start;
68 /* register an initial console printing routine for printk's */
72 /* we should really poll for DRAM size! */
74 high_memory = &dram_end;
76 if(romfs_in_flash || !romfs_length) {
77 /* if we have the romfs in flash, or if there is no rom filesystem,
78 * our free area starts directly after the BSS
80 memory_start = (unsigned long) &_end;
82 /* otherwise the free area starts after the ROM filesystem */
83 printk("ROM fs in RAM, size %lu bytes\n", romfs_length);
84 memory_start = romfs_start + romfs_length;
87 /* process 1's initial memory region is the kernel code/data */
89 init_mm.start_code = (unsigned long) &text_start;
90 init_mm.end_code = (unsigned long) &_etext;
91 init_mm.end_data = (unsigned long) &_edata;
92 init_mm.brk = (unsigned long) &_end;
94 #define PFN_UP(x) (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
95 #define PFN_DOWN(x) ((x) >> PAGE_SHIFT)
96 #define PFN_PHYS(x) ((x) << PAGE_SHIFT)
98 /* min_low_pfn points to the start of DRAM, start_pfn points
99 * to the first DRAM pages after the kernel, and max_low_pfn
100 * to the end of DRAM.
104 * partially used pages are not usable - thus
105 * we are rounding upwards:
108 start_pfn = PFN_UP(memory_start); /* usually c0000000 + kernel + romfs */
109 max_pfn = PFN_DOWN((unsigned long)high_memory); /* usually c0000000 + dram size */
112 * Initialize the boot-time allocator (start, end)
114 * We give it access to all our DRAM, but we could as well just have
115 * given it a small slice. No point in doing that though, unless we
116 * have non-contiguous memory and want the boot-stuff to be in, say,
119 * It will put a bitmap of the allocated pages in the beginning
120 * of the range we give it, but it won't mark the bitmaps pages
121 * as reserved. We have to do that ourselves below.
123 * We need to use init_bootmem_node instead of init_bootmem
124 * because our map starts at a quite high address (min_low_pfn).
127 max_low_pfn = max_pfn;
128 min_low_pfn = PAGE_OFFSET >> PAGE_SHIFT;
130 bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
134 /* And free all memory not belonging to the kernel (addr, size) */
136 free_bootmem(PFN_PHYS(start_pfn), PFN_PHYS(max_pfn - start_pfn));
139 * Reserve the bootmem bitmap itself as well. We do this in two
140 * steps (first step was init_bootmem()) because this catches
141 * the (very unlikely) case of us accidentally initializing the
142 * bootmem allocator with an invalid RAM area.
144 * Arguments are start, size
147 reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size);
149 /* paging_init() sets up the MMU and marks all pages as reserved */
153 /* We don't use a command line yet, so just re-initialize it without
154 saving anything that might be there. */
156 *cmdline_p = command_line;
158 #ifdef CONFIG_ETRAX_CMDLINE
159 strlcpy(command_line, CONFIG_ETRAX_CMDLINE, COMMAND_LINE_SIZE);
160 command_line[COMMAND_LINE_SIZE - 1] = '\0';
162 /* Save command line for future references. */
163 memcpy(saved_command_line, command_line, COMMAND_LINE_SIZE);
164 saved_command_line[COMMAND_LINE_SIZE - 1] = '\0';
167 /* give credit for the CRIS port */
168 show_etrax_copyright();
171 static void *c_start(struct seq_file *m, loff_t *pos)
173 /* We only got one CPU... */
174 return *pos < 1 ? (void *)1 : NULL;
177 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
183 static void c_stop(struct seq_file *m, void *v)
187 extern int show_cpuinfo(struct seq_file *m, void *v);
189 struct seq_operations cpuinfo_op = {
193 .show = show_cpuinfo,