setup.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1995 Linus Torvalds
 * Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999 Ralf Baechle
 * Copyright (C) 1996 Stoned Elipot
 * Copyright (C) 1999 Silicon Graphics, Inc.
 */
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/utsname.h>
#include <linux/a.out.h>
#include <linux/tty.h>
#ifdef CONFIG_BLK_DEV_RAM
#include <linux/blk.h>
#endif

#include <asm/asm.h>
#include <asm/bootinfo.h>
#include <asm/cachectl.h>
#include <asm/cpu.h>
#include <asm/stackframe.h>
#include <asm/system.h>
#include <asm/pgalloc.h>

#ifndef CONFIG_SMP
struct cpuinfo_mips cpu_data[1];
#endif

#ifdef CONFIG_VT
struct screen_info screen_info;
#endif

/*
 * Not all of the MIPS CPUs have the "wait" instruction available.  This
 * is set to true if it is available.  The wait instruction stops the
 * pipeline and reduces the power consumption of the CPU very much.
 */
char wait_available;

/*
 * Do we have a cyclecounter available?
 */
char cyclecounter_available;

/*
 * Set if box has EISA slots.
 */
int EISA_bus = 0;

#ifdef CONFIG_BLK_DEV_FD
extern struct fd_ops no_fd_ops;
struct fd_ops *fd_ops;
#endif

#ifdef CONFIG_BLK_DEV_IDE
extern struct ide_ops no_ide_ops;
struct ide_ops *ide_ops;
#endif

extern struct rtc_ops no_rtc_ops;
struct rtc_ops *rtc_ops;

extern struct kbd_ops no_kbd_ops;
struct kbd_ops *kbd_ops;

/*
 * Setup information
 *
 * These are initialized so they are in the .data section
 */
unsigned long mips_cputype = CPU_UNKNOWN;
unsigned long mips_machtype = MACH_UNKNOWN;
unsigned long mips_machgroup = MACH_GROUP_UNKNOWN;

struct boot_mem_map boot_mem_map;

unsigned char aux_device_present;

extern void load_mmu(void);

static char command_line[CL_SIZE] = { 0, };
       char saved_command_line[CL_SIZE];
extern char arcs_cmdline[CL_SIZE];

extern void ip22_setup(void);
extern void ip27_setup(void);

static inline void cpu_probe(void)
{
	unsigned int prid = read_32bit_cp0_register(CP0_PRID);

	switch(prid & 0xff00) {
	case PRID_IMP_R4000:
		if((prid & 0xff) == PRID_REV_R4400)
			mips_cputype = CPU_R4400SC;
		else
			mips_cputype = CPU_R4000SC;
		break;
	case PRID_IMP_R4600:
		mips_cputype = CPU_R4600;
		break;
	case PRID_IMP_R4700:
		mips_cputype = CPU_R4700;
		break;
	case PRID_IMP_R5000:
		mips_cputype = CPU_R5000;
		break;
	case PRID_IMP_NEVADA:
		mips_cputype = CPU_NEVADA;
		break;
	case PRID_IMP_R8000:
		mips_cputype = CPU_R8000;
		break;
	case PRID_IMP_R10000:
	case PRID_IMP_R12000:
		mips_cputype = CPU_R10000;
		break;
	default:
		mips_cputype = CPU_UNKNOWN;
	}
}

void __init setup_arch(char **cmdline_p)
{
	cpu_probe();
	load_mmu();

#ifdef CONFIG_SGI_IP22
	ip22_setup();
#endif
#ifdef CONFIG_SGI_IP27
	ip27_setup();
#endif

#ifdef CONFIG_ARC_MEMORY
	bootmem_init ();
#endif

	strncpy(command_line, arcs_cmdline, CL_SIZE);
	memcpy(saved_command_line, command_line, CL_SIZE);
	saved_command_line[CL_SIZE-1] = '\0';

	*cmdline_p = command_line;

	paging_init();
}