main.c
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上传日期:2013-02-24
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文件大小:19k
- /*
- * linux/init/main.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * GK 2/5/95 - Changed to support mounting root fs via NFS
- * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
- * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
- * Simplified starting of init: Michael A. Griffith <grif@acm.org>
- */
- #define __KERNEL_SYSCALLS__
- #include <linux/config.h>
- #include <linux/proc_fs.h>
- #include <linux/devfs_fs_kernel.h>
- #include <linux/unistd.h>
- #include <linux/string.h>
- #include <linux/ctype.h>
- #include <linux/delay.h>
- #include <linux/utsname.h>
- #include <linux/ioport.h>
- #include <linux/init.h>
- #include <linux/smp_lock.h>
- #include <linux/blk.h>
- #include <linux/hdreg.h>
- #include <linux/iobuf.h>
- #include <linux/bootmem.h>
- #include <linux/tty.h>
- #include <asm/io.h>
- #include <asm/bugs.h>
- #if defined(CONFIG_ARCH_S390)
- #include <asm/s390mach.h>
- #include <asm/ccwcache.h>
- #endif
- #ifdef CONFIG_PCI
- #include <linux/pci.h>
- #endif
- #ifdef CONFIG_DIO
- #include <linux/dio.h>
- #endif
- #ifdef CONFIG_ZORRO
- #include <linux/zorro.h>
- #endif
- #ifdef CONFIG_MTRR
- # include <asm/mtrr.h>
- #endif
- #ifdef CONFIG_NUBUS
- #include <linux/nubus.h>
- #endif
- #ifdef CONFIG_ISAPNP
- #include <linux/isapnp.h>
- #endif
- #ifdef CONFIG_IRDA
- extern int irda_proto_init(void);
- extern int irda_device_init(void);
- #endif
- #ifdef CONFIG_X86_LOCAL_APIC
- #include <asm/smp.h>
- #endif
- /*
- * Versions of gcc older than that listed below may actually compile
- * and link okay, but the end product can have subtle run time bugs.
- * To avoid associated bogus bug reports, we flatly refuse to compile
- * with a gcc that is known to be too old from the very beginning.
- */
- #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 91)
- #error Sorry, your GCC is too old. It builds incorrect kernels.
- #endif
- extern char _stext, _etext;
- extern char *linux_banner;
- static int init(void *);
- extern void init_IRQ(void);
- extern void init_modules(void);
- extern void sock_init(void);
- extern void fork_init(unsigned long);
- extern void mca_init(void);
- extern void sbus_init(void);
- extern void ppc_init(void);
- extern void sysctl_init(void);
- extern void signals_init(void);
- extern int init_pcmcia_ds(void);
- extern void free_initmem(void);
- #ifdef CONFIG_TC
- extern void tc_init(void);
- #endif
- extern void ecard_init(void);
- #if defined(CONFIG_SYSVIPC)
- extern void ipc_init(void);
- #endif
- #ifdef CONFIG_PERFMON
- extern void perfmon_init(void);
- #endif
- /*
- * Boot command-line arguments
- */
- #define MAX_INIT_ARGS 8
- #define MAX_INIT_ENVS 8
- extern void time_init(void);
- extern void softirq_init(void);
- int rows, cols;
- #ifdef CONFIG_BLK_DEV_INITRD
- unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
- #endif
- int root_mountflags = MS_RDONLY;
- char *execute_command;
- char root_device_name[64];
- static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
- static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
- static int __init profile_setup(char *str)
- {
- int par;
- if (get_option(&str,&par)) prof_shift = par;
- return 1;
- }
- __setup("profile=", profile_setup);
- static struct dev_name_struct {
- const char *name;
- const int num;
- } root_dev_names[] __initdata = {
- { "nfs", 0x00ff },
- { "hda", 0x0300 },
- { "hdb", 0x0340 },
- { "loop", 0x0700 },
- { "hdc", 0x1600 },
- { "hdd", 0x1640 },
- { "hde", 0x2100 },
- { "hdf", 0x2140 },
- { "hdg", 0x2200 },
- { "hdh", 0x2240 },
- { "hdi", 0x3800 },
- { "hdj", 0x3840 },
- { "hdk", 0x3900 },
- { "hdl", 0x3940 },
- { "hdm", 0x5800 },
- { "hdn", 0x5840 },
- { "hdo", 0x5900 },
- { "hdp", 0x5940 },
- { "hdq", 0x5A00 },
- { "hdr", 0x5A40 },
- { "hds", 0x5B00 },
- { "hdt", 0x5B40 },
- { "sda", 0x0800 },
- { "sdb", 0x0810 },
- { "sdc", 0x0820 },
- { "sdd", 0x0830 },
- { "sde", 0x0840 },
- { "sdf", 0x0850 },
- { "sdg", 0x0860 },
- { "sdh", 0x0870 },
- { "sdi", 0x0880 },
- { "sdj", 0x0890 },
- { "sdk", 0x08a0 },
- { "sdl", 0x08b0 },
- { "sdm", 0x08c0 },
- { "sdn", 0x08d0 },
- { "sdo", 0x08e0 },
- { "sdp", 0x08f0 },
- { "ada", 0x1c00 },
- { "adb", 0x1c10 },
- { "adc", 0x1c20 },
- { "add", 0x1c30 },
- { "ade", 0x1c40 },
- { "fd", 0x0200 },
- { "md", 0x0900 },
- { "xda", 0x0d00 },
- { "xdb", 0x0d40 },
- { "ram", 0x0100 },
- { "scd", 0x0b00 },
- { "mcd", 0x1700 },
- { "cdu535", 0x1800 },
- { "sonycd", 0x1800 },
- { "aztcd", 0x1d00 },
- { "cm206cd", 0x2000 },
- { "gscd", 0x1000 },
- { "sbpcd", 0x1900 },
- { "eda", 0x2400 },
- { "edb", 0x2440 },
- { "pda", 0x2d00 },
- { "pdb", 0x2d10 },
- { "pdc", 0x2d20 },
- { "pdd", 0x2d30 },
- { "pcd", 0x2e00 },
- { "pf", 0x2f00 },
- { "apblock", APBLOCK_MAJOR << 8},
- { "ddv", DDV_MAJOR << 8},
- { "jsfd", JSFD_MAJOR << 8},
- #if defined(CONFIG_ARCH_S390)
- { "dasda", (DASD_MAJOR << MINORBITS) },
- { "dasdb", (DASD_MAJOR << MINORBITS) + (1 << 2) },
- { "dasdc", (DASD_MAJOR << MINORBITS) + (2 << 2) },
- { "dasdd", (DASD_MAJOR << MINORBITS) + (3 << 2) },
- { "dasde", (DASD_MAJOR << MINORBITS) + (4 << 2) },
- { "dasdf", (DASD_MAJOR << MINORBITS) + (5 << 2) },
- { "dasdg", (DASD_MAJOR << MINORBITS) + (6 << 2) },
- { "dasdh", (DASD_MAJOR << MINORBITS) + (7 << 2) },
- #endif
- #if defined(CONFIG_BLK_CPQ_DA) || defined(CONFIG_BLK_CPQ_DA_MODULE)
- { "ida/c0d0p",0x4800 },
- { "ida/c0d1p",0x4810 },
- { "ida/c0d2p",0x4820 },
- { "ida/c0d3p",0x4830 },
- { "ida/c0d4p",0x4840 },
- { "ida/c0d5p",0x4850 },
- { "ida/c0d6p",0x4860 },
- { "ida/c0d7p",0x4870 },
- { "ida/c0d8p",0x4880 },
- { "ida/c0d9p",0x4890 },
- { "ida/c0d10p",0x48A0 },
- { "ida/c0d11p",0x48B0 },
- { "ida/c0d12p",0x48C0 },
- { "ida/c0d13p",0x48D0 },
- { "ida/c0d14p",0x48E0 },
- { "ida/c0d15p",0x48F0 },
- #endif
- #if defined(CONFIG_BLK_CPQ_CISS_DA) || defined(CONFIG_BLK_CPQ_CISS_DA_MODULE)
- { "cciss/c0d0p",0x6800 },
- { "cciss/c0d1p",0x6810 },
- { "cciss/c0d2p",0x6820 },
- { "cciss/c0d3p",0x6830 },
- { "cciss/c0d4p",0x6840 },
- { "cciss/c0d5p",0x6850 },
- { "cciss/c0d6p",0x6860 },
- { "cciss/c0d7p",0x6870 },
- { "cciss/c0d8p",0x6880 },
- { "cciss/c0d9p",0x6890 },
- { "cciss/c0d10p",0x68A0 },
- { "cciss/c0d11p",0x68B0 },
- { "cciss/c0d12p",0x68C0 },
- { "cciss/c0d13p",0x68D0 },
- { "cciss/c0d14p",0x68E0 },
- { "cciss/c0d15p",0x68F0 },
- #endif
- { "nftla", 0x5d00 },
- { "nftlb", 0x5d10 },
- { "nftlc", 0x5d20 },
- { "nftld", 0x5d30 },
- { "ftla", 0x2c00 },
- { "ftlb", 0x2c08 },
- { "ftlc", 0x2c10 },
- { "ftld", 0x2c18 },
- { "mtdblock", 0x1f00 },
- { NULL, 0 }
- };
- kdev_t __init name_to_kdev_t(char *line)
- {
- int base = 0;
- if (strncmp(line,"/dev/",5) == 0) {
- struct dev_name_struct *dev = root_dev_names;
- line += 5;
- do {
- int len = strlen(dev->name);
- if (strncmp(line,dev->name,len) == 0) {
- line += len;
- base = dev->num;
- break;
- }
- dev++;
- } while (dev->name);
- }
- return to_kdev_t(base + simple_strtoul(line,NULL,base?10:16));
- }
- static int __init root_dev_setup(char *line)
- {
- int i;
- char ch;
- ROOT_DEV = name_to_kdev_t(line);
- memset (root_device_name, 0, sizeof root_device_name);
- if (strncmp (line, "/dev/", 5) == 0) line += 5;
- for (i = 0; i < sizeof root_device_name - 1; ++i)
- {
- ch = line[i];
- if ( isspace (ch) || (ch == ',') || (ch == ' ') ) break;
- root_device_name[i] = ch;
- }
- return 1;
- }
- __setup("root=", root_dev_setup);
- static int __init checksetup(char *line)
- {
- struct kernel_param *p;
- p = &__setup_start;
- do {
- int n = strlen(p->str);
- if (!strncmp(line,p->str,n)) {
- if (p->setup_func(line+n))
- return 1;
- }
- p++;
- } while (p < &__setup_end);
- return 0;
- }
- /* this should be approx 2 Bo*oMips to start (note initial shift), and will
- still work even if initially too large, it will just take slightly longer */
- unsigned long loops_per_jiffy = (1<<12);
- /* This is the number of bits of precision for the loops_per_jiffy. Each
- bit takes on average 1.5/HZ seconds. This (like the original) is a little
- better than 1% */
- #define LPS_PREC 8
- void __init calibrate_delay(void)
- {
- unsigned long ticks, loopbit;
- int lps_precision = LPS_PREC;
- loops_per_jiffy = (1<<12);
- printk("Calibrating delay loop... ");
- while (loops_per_jiffy <<= 1) {
- /* wait for "start of" clock tick */
- ticks = jiffies;
- while (ticks == jiffies)
- /* nothing */;
- /* Go .. */
- ticks = jiffies;
- __delay(loops_per_jiffy);
- ticks = jiffies - ticks;
- if (ticks)
- break;
- }
- /* Do a binary approximation to get loops_per_jiffy set to equal one clock
- (up to lps_precision bits) */
- loops_per_jiffy >>= 1;
- loopbit = loops_per_jiffy;
- while ( lps_precision-- && (loopbit >>= 1) ) {
- loops_per_jiffy |= loopbit;
- ticks = jiffies;
- while (ticks == jiffies);
- ticks = jiffies;
- __delay(loops_per_jiffy);
- if (jiffies != ticks) /* longer than 1 tick */
- loops_per_jiffy &= ~loopbit;
- }
- /* Round the value and print it */
- printk("%lu.%02lu BogoMIPSn",
- loops_per_jiffy/(500000/HZ),
- (loops_per_jiffy/(5000/HZ)) % 100);
- }
- static int __init readonly(char *str)
- {
- if (*str)
- return 0;
- root_mountflags |= MS_RDONLY;
- return 1;
- }
- static int __init readwrite(char *str)
- {
- if (*str)
- return 0;
- root_mountflags &= ~MS_RDONLY;
- return 1;
- }
- static int __init debug_kernel(char *str)
- {
- if (*str)
- return 0;
- console_loglevel = 10;
- return 1;
- }
- static int __init quiet_kernel(char *str)
- {
- if (*str)
- return 0;
- console_loglevel = 4;
- return 1;
- }
- __setup("ro", readonly);
- __setup("rw", readwrite);
- __setup("debug", debug_kernel);
- __setup("quiet", quiet_kernel);
- /*
- * This is a simple kernel command line parsing function: it parses
- * the command line, and fills in the arguments/environment to init
- * as appropriate. Any cmd-line option is taken to be an environment
- * variable if it contains the character '='.
- *
- * This routine also checks for options meant for the kernel.
- * These options are not given to init - they are for internal kernel use only.
- */
- static void __init parse_options(char *line)
- {
- char *next,*quote;
- int args, envs;
- if (!*line)
- return;
- args = 0;
- envs = 1; /* TERM is set to 'linux' by default */
- next = line;
- while ((line = next) != NULL) {
- quote = strchr(line,'"');
- next = strchr(line, ' ');
- while (next != NULL && quote != NULL && quote < next) {
- /* we found a left quote before the next blank
- * now we have to find the matching right quote
- */
- next = strchr(quote+1, '"');
- if (next != NULL) {
- quote = strchr(next+1, '"');
- next = strchr(next+1, ' ');
- }
- }
- if (next != NULL)
- *next++ = 0;
- if (!strncmp(line,"init=",5)) {
- line += 5;
- execute_command = line;
- /* In case LILO is going to boot us with default command line,
- * it prepends "auto" before the whole cmdline which makes
- * the shell think it should execute a script with such name.
- * So we ignore all arguments entered _before_ init=... [MJ]
- */
- args = 0;
- continue;
- }
- if (checksetup(line))
- continue;
-
- /*
- * Then check if it's an environment variable or
- * an option.
- */
- if (strchr(line,'=')) {
- if (envs >= MAX_INIT_ENVS)
- break;
- envp_init[++envs] = line;
- } else {
- if (args >= MAX_INIT_ARGS)
- break;
- if (*line)
- argv_init[++args] = line;
- }
- }
- argv_init[args+1] = NULL;
- envp_init[envs+1] = NULL;
- }
- extern void setup_arch(char **);
- extern void cpu_idle(void);
- unsigned long wait_init_idle;
- #ifndef CONFIG_SMP
- #ifdef CONFIG_X86_LOCAL_APIC
- static void __init smp_init(void)
- {
- APIC_init_uniprocessor();
- }
- #else
- #define smp_init() do { } while (0)
- #endif
- #else
- /* Called by boot processor to activate the rest. */
- static void __init smp_init(void)
- {
- /* Get other processors into their bootup holding patterns. */
- smp_boot_cpus();
- wait_init_idle = cpu_online_map;
- clear_bit(current->processor, &wait_init_idle); /* Don't wait on me! */
- smp_threads_ready=1;
- smp_commence();
- /* Wait for the other cpus to set up their idle processes */
- printk("Waiting on wait_init_idle (map = 0x%lx)n", wait_init_idle);
- while (wait_init_idle) {
- cpu_relax();
- barrier();
- }
- printk("All processors have done init_idlen");
- }
- #endif
- /*
- * We need to finalize in a non-__init function or else race conditions
- * between the root thread and the init thread may cause start_kernel to
- * be reaped by free_initmem before the root thread has proceeded to
- * cpu_idle.
- */
- static void rest_init(void)
- {
- kernel_thread(init, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGNAL);
- unlock_kernel();
- current->need_resched = 1;
- cpu_idle();
- }
- /*
- * Activate the first processor.
- */
- asmlinkage void __init start_kernel(void)
- {
- char * command_line;
- unsigned long mempages;
- extern char saved_command_line[];
- /*
- * Interrupts are still disabled. Do necessary setups, then
- * enable them
- */
- lock_kernel();
- printk(linux_banner);
- setup_arch(&command_line);
- printk("Kernel command line: %sn", saved_command_line);
- parse_options(command_line);
- trap_init();
- init_IRQ();
- sched_init();
- softirq_init();
- time_init();
- /*
- * HACK ALERT! This is early. We're enabling the console before
- * we've done PCI setups etc, and console_init() must be aware of
- * this. But we do want output early, in case something goes wrong.
- */
- console_init();
- #ifdef CONFIG_MODULES
- init_modules();
- #endif
- if (prof_shift) {
- unsigned int size;
- /* only text is profiled */
- prof_len = (unsigned long) &_etext - (unsigned long) &_stext;
- prof_len >>= prof_shift;
-
- size = prof_len * sizeof(unsigned int) + PAGE_SIZE-1;
- prof_buffer = (unsigned int *) alloc_bootmem(size);
- }
- kmem_cache_init();
- sti();
- calibrate_delay();
- #ifdef CONFIG_BLK_DEV_INITRD
- if (initrd_start && !initrd_below_start_ok &&
- initrd_start < min_low_pfn << PAGE_SHIFT) {
- printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
- "disabling it.n",initrd_start,min_low_pfn << PAGE_SHIFT);
- initrd_start = 0;
- }
- #endif
- mem_init();
- kmem_cache_sizes_init();
- pgtable_cache_init();
- #ifdef CONFIG_PERFMON
- perfmon_init();
- #endif
- mempages = num_physpages;
- fork_init(mempages);
- proc_caches_init();
- vfs_caches_init(mempages);
- buffer_init(mempages);
- page_cache_init(mempages);
- #if defined(CONFIG_ARCH_S390)
- ccwcache_init();
- #endif
- signals_init();
- #ifdef CONFIG_PROC_FS
- proc_root_init();
- #endif
- #if defined(CONFIG_SYSVIPC)
- ipc_init();
- #endif
- check_bugs();
- printk("POSIX conformance testing by UNIFIXn");
- /*
- * We count on the initial thread going ok
- * Like idlers init is an unlocked kernel thread, which will
- * make syscalls (and thus be locked).
- */
- smp_init();
- rest_init();
- }
- #ifdef CONFIG_BLK_DEV_INITRD
- static int do_linuxrc(void * shell)
- {
- static char *argv[] = { "linuxrc", NULL, };
- close(0);close(1);close(2);
- setsid();
- (void) open("/dev/console",O_RDWR,0);
- (void) dup(0);
- (void) dup(0);
- return execve(shell, argv, envp_init);
- }
- #endif
- struct task_struct *child_reaper = &init_task;
- static void __init do_initcalls(void)
- {
- initcall_t *call;
- call = &__initcall_start;
- do {
- (*call)();
- call++;
- } while (call < &__initcall_end);
- /* Make sure there is no pending stuff from the initcall sequence */
- flush_scheduled_tasks();
- }
- /*
- * Ok, the machine is now initialized. None of the devices
- * have been touched yet, but the CPU subsystem is up and
- * running, and memory and process management works.
- *
- * Now we can finally start doing some real work..
- */
- static void __init do_basic_setup(void)
- {
- /*
- * Tell the world that we're going to be the grim
- * reaper of innocent orphaned children.
- *
- * We don't want people to have to make incorrect
- * assumptions about where in the task array this
- * can be found.
- */
- child_reaper = current;
- #if defined(CONFIG_MTRR) /* Do this after SMP initialization */
- /*
- * We should probably create some architecture-dependent "fixup after
- * everything is up" style function where this would belong better
- * than in init/main.c..
- */
- mtrr_init();
- #endif
- #ifdef CONFIG_SYSCTL
- sysctl_init();
- #endif
- /*
- * Ok, at this point all CPU's should be initialized, so
- * we can start looking into devices..
- */
- #if defined(CONFIG_ARCH_S390)
- s390_init_machine_check();
- #endif
- #ifdef CONFIG_PCI
- pci_init();
- #endif
- #ifdef CONFIG_SBUS
- sbus_init();
- #endif
- #if defined(CONFIG_PPC)
- ppc_init();
- #endif
- #ifdef CONFIG_MCA
- mca_init();
- #endif
- #ifdef CONFIG_ARCH_ACORN
- ecard_init();
- #endif
- #ifdef CONFIG_ZORRO
- zorro_init();
- #endif
- #ifdef CONFIG_DIO
- dio_init();
- #endif
- #ifdef CONFIG_NUBUS
- nubus_init();
- #endif
- #ifdef CONFIG_ISAPNP
- isapnp_init();
- #endif
- #ifdef CONFIG_TC
- tc_init();
- #endif
- /* Networking initialization needs a process context */
- sock_init();
- start_context_thread();
- do_initcalls();
- #ifdef CONFIG_IRDA
- irda_proto_init();
- irda_device_init(); /* Must be done after protocol initialization */
- #endif
- #ifdef CONFIG_PCMCIA
- init_pcmcia_ds(); /* Do this last */
- #endif
- }
- extern void rd_load(void);
- extern void initrd_load(void);
- /*
- * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
- */
- static void prepare_namespace(void)
- {
- #ifdef CONFIG_BLK_DEV_INITRD
- int real_root_mountflags = root_mountflags;
- if (!initrd_start)
- mount_initrd = 0;
- if (mount_initrd)
- root_mountflags &= ~MS_RDONLY;
- real_root_dev = ROOT_DEV;
- #endif
- #ifdef CONFIG_BLK_DEV_RAM
- #ifdef CONFIG_BLK_DEV_INITRD
- if (mount_initrd)
- initrd_load();
- else
- #endif
- rd_load();
- #endif
- /* Mount the root filesystem.. */
- mount_root();
- mount_devfs_fs ();
- #ifdef CONFIG_BLK_DEV_INITRD
- root_mountflags = real_root_mountflags;
- if (mount_initrd && ROOT_DEV != real_root_dev
- && MAJOR(ROOT_DEV) == RAMDISK_MAJOR && MINOR(ROOT_DEV) == 0) {
- int error;
- int i, pid;
- pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
- if (pid > 0) {
- while (pid != wait(&i)) {
- current->policy |= SCHED_YIELD;
- schedule();
- }
- }
- if (MAJOR(real_root_dev) != RAMDISK_MAJOR
- || MINOR(real_root_dev) != 0) {
- error = change_root(real_root_dev,"/initrd");
- if (error)
- printk(KERN_ERR "Change root to /initrd: "
- "error %dn",error);
- }
- }
- #endif
- }
- static int init(void * unused)
- {
- lock_kernel();
- do_basic_setup();
- prepare_namespace();
- /*
- * Ok, we have completed the initial bootup, and
- * we're essentially up and running. Get rid of the
- * initmem segments and start the user-mode stuff..
- */
- free_initmem();
- unlock_kernel();
- if (open("/dev/console", O_RDWR, 0) < 0)
- printk("Warning: unable to open an initial console.n");
- (void) dup(0);
- (void) dup(0);
- // The company information is shown here.
- printk("=============================================================================n");
- printk("# Nanjing Electric Power Automation Equipment Third Factory Co., Ltd. #n");
- printk("# Homepage: http://www.njnzsc.com E-mail: nzscxk@163.com #n");
- printk("# Tel: (025)84584588-808 Fax: (025)84646396 compiled by J.H.F. #n");
- printk("=============================================================================n");
- /*
- * We try each of these until one succeeds.
- *
- * The Bourne shell can be used instead of init if we are
- * trying to recover a really broken machine.
- */
- if (execute_command)
- execve(execute_command,argv_init,envp_init);
- execve("/sbin/init",argv_init,envp_init);
- execve("/etc/init",argv_init,envp_init);
- execve("/bin/init",argv_init,envp_init);
- execve("/bin/sh",argv_init,envp_init);
- panic("No init found. Try passing init= option to kernel.");
- }