linux/arch/cris/kernel/setup.c

205 lines
5.5 KiB
C

/*
*
* 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/init.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <asm/pgtable.h>
#include <linux/seq_file.h>
#include <linux/screen_info.h>
#include <linux/utsname.h>
#include <linux/pfn.h>
#include <linux/cpu.h>
#include <asm/setup.h>
#include <arch/system.h>
/*
* Setup options
*/
struct screen_info screen_info;
extern int root_mountflags;
extern char _etext, _edata, _end;
char __initdata cris_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 */
static struct cpu cpu_devices[NR_CPUS];
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;
/* 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, BOOTMEM_DEFAULT);
/* paging_init() sets up the MMU and marks all pages as reserved */
paging_init();
*cmdline_p = cris_command_line;
#ifdef CONFIG_ETRAX_CMDLINE
if (!strcmp(cris_command_line, "")) {
strlcpy(cris_command_line, CONFIG_ETRAX_CMDLINE, COMMAND_LINE_SIZE);
cris_command_line[COMMAND_LINE_SIZE - 1] = '\0';
}
#endif
/* Save command line for future references. */
memcpy(boot_command_line, cris_command_line, COMMAND_LINE_SIZE);
boot_command_line[COMMAND_LINE_SIZE - 1] = '\0';
/* give credit for the CRIS port */
show_etrax_copyright();
/* Setup utsname */
strcpy(init_utsname()->machine, cris_machine_name);
}
static void *c_start(struct seq_file *m, loff_t *pos)
{
return *pos < nr_cpu_ids ? (void *)(int)(*pos + 1) : NULL;
}
static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return c_start(m, pos);
}
static void c_stop(struct seq_file *m, void *v)
{
}
extern int show_cpuinfo(struct seq_file *m, void *v);
const struct seq_operations cpuinfo_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = show_cpuinfo,
};
static int __init topology_init(void)
{
int i;
for_each_possible_cpu(i) {
return register_cpu(&cpu_devices[i], i);
}
return 0;
}
subsys_initcall(topology_init);