| /* |
| * 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> |
| |
| #include <linux/device.h> |
| |
| #if defined(CONFIG_ARCH_S390) |
| #include <asm/s390mach.h> |
| #include <asm/ccwcache.h> |
| #endif |
| |
| #ifdef CONFIG_MTRR |
| # include <asm/mtrr.h> |
| #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 sysctl_init(void); |
| extern void signals_init(void); |
| |
| extern void free_initmem(void); |
| |
| #ifdef CONFIG_TC |
| extern void tc_init(void); |
| #endif |
| |
| #if defined(CONFIG_SYSVIPC) |
| extern void ipc_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; |
| |
| char *execute_command; |
| |
| static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; |
| 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 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 BogoMIPS\n", |
| loops_per_jiffy/(500000/HZ), |
| (loops_per_jiffy/(5000/HZ)) % 100); |
| } |
| |
| 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("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); |
| |
| #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(); |
| |
| smp_threads_ready=1; |
| smp_commence(); |
| } |
| |
| #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(); |
| 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: %s\n", 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(); |
| |
| 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 UNIFIX\n"); |
| |
| init_idle(current, smp_processor_id()); |
| /* |
| * 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(); |
| |
| /* Do the rest non-__init'ed, we're now alive */ |
| rest_init(); |
| } |
| |
| 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 |
| |
| /* bring up the device tree */ |
| device_driver_init(); |
| |
| /* Networking initialization needs a process context */ |
| sock_init(); |
| |
| start_context_thread(); |
| do_initcalls(); |
| } |
| |
| extern void prepare_namespace(void); |
| |
| 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); |
| |
| /* |
| * 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."); |
| } |