/* * 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 */ #define __KERNEL_SYSCALLS__ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(CONFIG_ARCH_S390) #include #include #endif #ifdef CONFIG_ACPI #include #endif #ifdef CONFIG_PCI #include #endif #ifdef CONFIG_DIO #include #endif #ifdef CONFIG_ZORRO #include #endif #ifdef CONFIG_MTRR # include #endif #ifdef CONFIG_NUBUS #include #endif #ifdef CONFIG_ISAPNP #include #endif #ifdef CONFIG_IRDA extern int irda_proto_init(void); extern int irda_device_init(void); #endif #ifdef CONFIG_X86_LOCAL_APIC #include #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_ACPI_BUS extern void acpi_early_init(void); #else static inline void acpi_early_init(void) { } #endif #ifdef CONFIG_TC extern void tc_init(void); #endif extern void ecard_init(void); #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); 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_idle\n"); } #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; 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(); /* * For architectures that have highmem, num_mappedpages represents * the amount of memory the kernel can use. For other architectures * it's the same as the total pages. We need both numbers because * some subsystems need to initialize based on how much memory the * kernel can use. */ if (num_mappedpages == 0) num_mappedpages = num_physpages; fork_init(num_mappedpages); proc_caches_init(); vfs_caches_init(num_physpages); buffer_init(num_physpages); page_cache_init(num_physpages); #if defined(CONFIG_ARCH_S390) ccwcache_init(); #endif signals_init(); #ifdef CONFIG_PROC_FS proc_root_init(); #endif check_bugs(); acpi_early_init(); /* before LAPIC and SMP init */ 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). */ smp_init(); #if defined(CONFIG_SYSVIPC) ipc_init(); #endif 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 #ifdef CONFIG_ACPI_INTERPRETER acpi_init(); #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 } static void run_init_process(char *init_filename) { argv_init[0] = init_filename; execve(init_filename, argv_init, envp_init); } extern void prepare_namespace(void); static int init(void * unused) { struct files_struct *files; 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(); /* * Right now we are a thread sharing with a ton of kernel * stuff. We don't want to end up in user space in that state */ files = current->files; if(unshare_files()) panic("unshare"); put_files_struct(files); 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) run_init_process(execute_command); run_init_process("/sbin/init"); run_init_process("/etc/init"); run_init_process("/bin/init"); run_init_process("/bin/sh"); panic("No init found. Try passing init= option to kernel."); }