由bootload进入linux后由head.s进入了start_kernel了.
asmlinkage void __init start_kernel(void)
{
char * command_line;
extern struct kernel_param __start___param[], __stop___param[];
………………..
setup_arch(&command_line);
………….
………..
vfs_caches_init(num_physpages); ………….
…………...
rest_init();
}
重要函数解释
1.Setup_arch是解释bootloader传过来的参数，并附相关参数。
void __init setup_arch(char **cmdline_p)
{
struct tag *tags = (struct tag *)&init_tags;
struct machine_desc *mdesc;
char *from = default_command_line;
setup_processor();
mdesc = setup_machine(machine_arch_type);
machine_name = mdesc->name;
if (mdesc->soft_reboot)
reboot_setup("s");
if (mdesc->boot_params)
tags = phys_to_virt(mdesc->boot_params);
/*
* If we have the old style parameters, convert them to
* a tag list.
*/
&nb
/*
* linux/fs/file_dev.c
*
* (C) 1991 Linus Torvalds
*/
#include <errno.h>
#include <fcntl.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <asm/segment.h>
#define MIN(a,b) (((a)<(b))?(a):(b))
#defi ......
