| /* |
| * 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/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/initrd.h> |
| #include <linux/hdreg.h> |
| #include <linux/bootmem.h> |
| #include <linux/tty.h> |
| #include <linux/gfp.h> |
| #include <linux/percpu.h> |
| #include <linux/kernel_stat.h> |
| #include <linux/security.h> |
| #include <linux/workqueue.h> |
| #include <linux/profile.h> |
| #include <linux/rcupdate.h> |
| #include <linux/moduleparam.h> |
| #include <linux/writeback.h> |
| #include <linux/cpu.h> |
| |
| #include <asm/io.h> |
| #include <asm/bugs.h> |
| |
| /* |
| * This is one of the first .c files built. Error out early |
| * if we have compiler trouble.. |
| */ |
| #if __GNUC__ == 2 && __GNUC_MINOR__ == 96 |
| #ifdef CONFIG_FRAME_POINTER |
| #error This compiler cannot compile correctly with frame pointers enabled |
| #endif |
| #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__ < 95) |
| #error Sorry, your GCC is too old. It builds incorrect kernels. |
| #endif |
| |
| extern char *linux_banner; |
| |
| static int init(void *); |
| |
| extern void init_IRQ(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 buffer_init(void); |
| extern void pidhash_init(void); |
| extern void pidmap_init(void); |
| extern void pte_chain_init(void); |
| extern void radix_tree_init(void); |
| extern void free_initmem(void); |
| extern void populate_rootfs(void); |
| extern void driver_init(void); |
| |
| #ifdef CONFIG_TC |
| extern void tc_init(void); |
| #endif |
| |
| #if defined(CONFIG_SYSVIPC) |
| extern void ipc_init(void); |
| #endif |
| |
| /* |
| * Are we up and running (ie do we have all the infrastructure |
| * set up) |
| */ |
| int system_running = 0; |
| |
| /* |
| * 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; |
| |
| /* Setup configured maximum number of CPUs to activate */ |
| static unsigned int max_cpus = NR_CPUS; |
| |
| /* |
| * Setup routine for controlling SMP activation |
| * |
| * Command-line option of "nosmp" or "maxcpus=0" will disable SMP |
| * activation entirely (the MPS table probe still happens, though). |
| * |
| * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer |
| * greater than 0, limits the maximum number of CPUs activated in |
| * SMP mode to <NUM>. |
| */ |
| static int __init nosmp(char *str) |
| { |
| max_cpus = 0; |
| return 1; |
| } |
| |
| __setup("nosmp", nosmp); |
| |
| static int __init maxcpus(char *str) |
| { |
| get_option(&str, &max_cpus); |
| return 1; |
| } |
| |
| __setup("maxcpus=", maxcpus); |
| |
| static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; |
| char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; |
| |
| __setup("profile=", profile_setup); |
| |
| static int __init obsolete_checksetup(char *line) |
| { |
| struct obs_kernel_param *p; |
| extern struct obs_kernel_param __setup_start, __setup_end; |
| |
| 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); |
| |
| /* Unknown boot options get handed to init, unless they look like |
| failed parameters */ |
| static int __init unknown_bootoption(char *param, char *val) |
| { |
| /* Change NUL term back to "=", to make "param" the whole string. */ |
| if (val) |
| val[-1] = '='; |
| |
| /* Handle obsolete-style parameters */ |
| if (obsolete_checksetup(param)) |
| return 0; |
| |
| /* Preemptive maintenance for "why didn't my mispelled command |
| line work?" */ |
| if (strchr(param, '.') && (!val || strchr(param, '.') < val)) { |
| printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param); |
| return 0; |
| } |
| |
| if (val) { |
| /* Environment option */ |
| unsigned int i; |
| for (i = 0; envp_init[i]; i++) { |
| if (i == MAX_INIT_ENVS) |
| panic("Too many boot env vars at `%s'", param); |
| } |
| envp_init[i] = param; |
| } else { |
| /* Command line option */ |
| unsigned int i; |
| for (i = 0; argv_init[i]; i++) { |
| if (i == MAX_INIT_ARGS) |
| panic("Too many boot init vars at `%s'",param); |
| } |
| argv_init[i] = param; |
| } |
| return 0; |
| } |
| |
| static int __init init_setup(char *str) |
| { |
| unsigned int i; |
| |
| execute_command = str; |
| /* 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] |
| */ |
| for (i = 1; i < MAX_INIT_ARGS; i++) |
| argv_init[i] = NULL; |
| return 1; |
| } |
| __setup("init=", init_setup); |
| |
| 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 |
| |
| static inline void setup_per_cpu_areas(void) { } |
| static inline void smp_prepare_cpus(unsigned int maxcpus) { } |
| |
| #else |
| |
| #ifdef __GENERIC_PER_CPU |
| unsigned long __per_cpu_offset[NR_CPUS]; |
| |
| static void __init setup_per_cpu_areas(void) |
| { |
| unsigned long size, i; |
| char *ptr; |
| /* Created by linker magic */ |
| extern char __per_cpu_start[], __per_cpu_end[]; |
| |
| /* Copy section for each CPU (we discard the original) */ |
| size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES); |
| #ifdef CONFIG_MODULES |
| if (size < PERCPU_ENOUGH_ROOM) |
| size = PERCPU_ENOUGH_ROOM; |
| #endif |
| |
| ptr = alloc_bootmem(size * NR_CPUS); |
| |
| for (i = 0; i < NR_CPUS; i++, ptr += size) { |
| __per_cpu_offset[i] = ptr - __per_cpu_start; |
| memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start); |
| } |
| } |
| #endif /* !__GENERIC_PER_CPU */ |
| |
| /* Called by boot processor to activate the rest. */ |
| static void __init smp_init(void) |
| { |
| unsigned int i; |
| |
| /* FIXME: This should be done in userspace --RR */ |
| for (i = 0; i < NR_CPUS; i++) { |
| if (num_online_cpus() >= max_cpus) |
| break; |
| if (cpu_possible(i) && !cpu_online(i)) { |
| printk("Bringing up %i\n", i); |
| cpu_up(i); |
| } |
| } |
| |
| /* Any cleanup work */ |
| printk("CPUS done %u\n", max_cpus); |
| smp_cpus_done(max_cpus); |
| #if 0 |
| /* Get other processors into their bootup holding patterns. */ |
| |
| smp_threads_ready=1; |
| smp_commence(); |
| #endif |
| } |
| |
| #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_KERNEL); |
| unlock_kernel(); |
| cpu_idle(); |
| } |
| |
| /* |
| * Activate the first processor. |
| */ |
| |
| asmlinkage void __init start_kernel(void) |
| { |
| char * command_line; |
| extern char saved_command_line[]; |
| extern struct kernel_param __start___param[], __stop___param[]; |
| /* |
| * Interrupts are still disabled. Do necessary setups, then |
| * enable them |
| */ |
| lock_kernel(); |
| printk(linux_banner); |
| setup_arch(&command_line); |
| setup_per_zone_pages_min(); |
| setup_per_cpu_areas(); |
| |
| /* |
| * Mark the boot cpu "online" so that it can call console drivers in |
| * printk() and can access its per-cpu storage. |
| */ |
| smp_prepare_boot_cpu(); |
| |
| build_all_zonelists(); |
| page_alloc_init(); |
| printk("Kernel command line: %s\n", saved_command_line); |
| parse_args("Booting kernel", command_line, __start___param, |
| __stop___param - __start___param, |
| &unknown_bootoption); |
| trap_init(); |
| rcu_init(); |
| init_IRQ(); |
| pidhash_init(); |
| 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(); |
| profile_init(); |
| local_irq_enable(); |
| 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 |
| page_address_init(); |
| mem_init(); |
| kmem_cache_init(); |
| pidmap_init(); |
| pgtable_cache_init(); |
| pte_chain_init(); |
| fork_init(num_physpages); |
| proc_caches_init(); |
| buffer_init(); |
| security_scaffolding_startup(); |
| vfs_caches_init(num_physpages); |
| radix_tree_init(); |
| signals_init(); |
| /* rootfs populating might need page-writeback */ |
| page_writeback_init(); |
| populate_rootfs(); |
| #ifdef CONFIG_PROC_FS |
| proc_root_init(); |
| #endif |
| #if defined(CONFIG_SYSVIPC) |
| ipc_init(); |
| #endif |
| check_bugs(); |
| printk("POSIX conformance testing by UNIFIX\n"); |
| |
| /* |
| * We count on the initial thread going ok |
| * Like idlers init is an unlocked kernel thread, which will |
| * make syscalls (and thus be locked). |
| */ |
| init_idle(current, smp_processor_id()); |
| |
| /* Do the rest non-__init'ed, we're now alive */ |
| rest_init(); |
| } |
| |
| int __initdata initcall_debug; |
| |
| static int __init initcall_debug_setup(char *str) |
| { |
| initcall_debug = 1; |
| return 1; |
| } |
| __setup("initcall_debug", initcall_debug_setup); |
| |
| struct task_struct *child_reaper = &init_task; |
| |
| extern initcall_t __initcall_start, __initcall_end; |
| |
| static void __init do_initcalls(void) |
| { |
| initcall_t *call; |
| int count = preempt_count(); |
| |
| for (call = &__initcall_start; call < &__initcall_end; call++) { |
| char *msg; |
| |
| if (initcall_debug) |
| printk("calling initcall 0x%p\n", *call); |
| |
| (*call)(); |
| |
| msg = NULL; |
| if (preempt_count() != count) { |
| msg = "preemption imbalance"; |
| preempt_count() = count; |
| } |
| if (irqs_disabled()) { |
| msg = "disabled interrupts"; |
| local_irq_enable(); |
| } |
| if (msg) { |
| printk("error in initcall at 0x%p: " |
| "returned with %s\n", *call, msg); |
| } |
| } |
| |
| /* Make sure there is no pending stuff from the initcall sequence */ |
| flush_scheduled_work(); |
| } |
| |
| /* |
| * 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) |
| { |
| driver_init(); |
| |
| #ifdef CONFIG_SYSCTL |
| sysctl_init(); |
| #endif |
| |
| /* Networking initialization needs a process context */ |
| sock_init(); |
| |
| init_workqueues(); |
| do_initcalls(); |
| } |
| |
| static void do_pre_smp_initcalls(void) |
| { |
| extern int spawn_ksoftirqd(void); |
| #ifdef CONFIG_SMP |
| extern int migration_init(void); |
| |
| migration_init(); |
| #endif |
| node_nr_running_init(); |
| spawn_ksoftirqd(); |
| } |
| |
| extern void prepare_namespace(void); |
| |
| static int init(void * unused) |
| { |
| static char * argv_sh[] = { "sh", NULL, }; |
| |
| lock_kernel(); |
| /* |
| * 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; |
| |
| /* Sets up cpus_possible() */ |
| smp_prepare_cpus(max_cpus); |
| |
| do_pre_smp_initcalls(); |
| |
| smp_init(); |
| 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(); |
| system_running = 1; |
| |
| 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_sh,envp_init); |
| panic("No init found. Try passing init= option to kernel."); |
| } |