/* * 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 #ifdef CONFIG_PCI #include #endif #ifdef CONFIG_DIO #include #endif #ifdef CONFIG_ZORRO #include #endif #ifdef CONFIG_MTRR # include #endif #ifdef CONFIG_3215_CONSOLE extern int con3215_activate(void); #endif #ifdef CONFIG_MAC extern void nubus_init(void); #endif #ifdef CONFIG_ISAPNP #include #endif #ifdef CONFIG_IRDA #include #endif #ifdef CONFIG_X86_IO_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__ < 7) #error sorry, your GCC is too old. It builds incorrect kernels. #endif extern char _stext, _etext; extern char *linux_banner; extern int console_loglevel; static int init(void *); extern void init_IRQ(void); extern void init_modules(void); extern void init_inventory(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 filescache_init(void); extern void signals_init(void); extern void bdev_init(void); extern int init_pcmcia_ds(void); extern int usb_init(void); extern void free_initmem(void); extern void filesystem_setup(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 #if defined(CONFIG_QUOTA) extern void dquot_init_hash(void); #endif #ifdef CONFIG_REMOTE_DEBUG #include #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 kdev_t real_root_dev; #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, }; /* * Read an int from an option string; if available accept a subsequent * comma as well. * * Return values: * 0 : no int in string * 1 : int found, no subsequent comma * 2 : int found including a subsequent comma */ int get_option(char **str, int *pint) { char *cur = *str; if (!cur || !(*cur)) return 0; *pint = simple_strtol(cur,str,0); if (cur==*str) return 0; if (**str==',') { (*str)++; return 2; } return 1; } char *get_options(char *str, int nints, int *ints) { int res,i=1; while (iname); 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 == '\0') ) 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_sec = (1<<12); /* This is the number of bits of precision for the loops_per_second. 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_sec = (1<<12); printk("Calibrating delay loop... "); while (loops_per_sec <<= 1) { /* wait for "start of" clock tick */ ticks = jiffies; while (ticks == jiffies) /* nothing */; /* Go .. */ ticks = jiffies; __delay(loops_per_sec); ticks = jiffies - ticks; if (ticks) break; } /* Do a binary approximation to get loops_per_second set to equal one clock (up to lps_precision bits) */ loops_per_sec >>= 1; loopbit = loops_per_sec; while ( lps_precision-- && (loopbit >>= 1) ) { loops_per_sec |= loopbit; ticks = jiffies; while (ticks == jiffies); ticks = jiffies; __delay(loops_per_sec); if (jiffies != ticks) /* longer than 1 tick */ loops_per_sec &= ~loopbit; } /* finally, adjust loops per second in terms of seconds instead of clocks */ loops_per_sec *= HZ; /* Round the value and print it */ printk("%lu.%02lu BogoMIPS\n", (loops_per_sec+2500)/500000, ((loops_per_sec+2500)/5000) % 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; } __setup("ro", readonly); __setup("rw", readwrite); __setup("debug", debug_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_IO_APIC static void __init smp_init(void) { IO_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 /* * Activate the first processor. */ asmlinkage void __init start_kernel(void) { char * command_line; unsigned long mempages; /* * Interrupts are still disabled. Do necessary setups, then * enable them */ lock_kernel(); printk(linux_banner); setup_arch(&command_line); trap_init(); init_IRQ(); sched_init(); time_init(); softirq_init(); parse_options(command_line); /* * 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 #ifdef CONFIG_BINFMT_IRIX init_inventory(); #endif mem_init(); kmem_cache_sizes_init(); #ifdef CONFIG_3215_CONSOLE con3215_activate(); #endif #ifdef CONFIG_PROC_FS proc_root_init(); #endif mempages = num_physpages; fork_init(mempages); filescache_init(); dcache_init(mempages); vma_init(); buffer_init(mempages); page_cache_init(mempages); kiobuf_setup(); signals_init(); bdev_init(); inode_init(mempages); file_table_init(); #if defined(CONFIG_SYSVIPC) ipc_init(); #endif #if defined(CONFIG_QUOTA) dquot_init_hash(); #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). */ smp_init(); kernel_thread(init, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGHAND); unlock_kernel(); current->need_resched = 1; cpu_idle(); } #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); } /* * 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) { #ifdef CONFIG_BLK_DEV_INITRD int real_root_mountflags; #endif /* * 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.. */ #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_MAC nubus_init(); #endif #ifdef CONFIG_ISAPNP isapnp_init(); #endif #ifdef CONFIG_USB usb_init(); /* Do this before doing initcalls, so that we can make usbcore initialize here, and all drivers initialize later */ #endif #ifdef CONFIG_TC tc_init(); #endif /* Networking initialization needs a process context */ sock_init(); #ifdef CONFIG_BLK_DEV_INITRD real_root_dev = ROOT_DEV; real_root_mountflags = root_mountflags; if (initrd_start && mount_initrd) root_mountflags &= ~MS_RDONLY; else mount_initrd =0; #endif do_initcalls(); /* .. filesystems .. */ filesystem_setup(); #ifdef CONFIG_IRDA irda_device_init(); /* Must be done after protocol initialization */ #endif #ifdef CONFIG_PCMCIA init_pcmcia_ds(); /* Do this last */ #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)); if (MAJOR(real_root_dev) != RAMDISK_MAJOR || MINOR(real_root_dev) != 0) { #ifdef CONFIG_BLK_DEV_MD autodetect_raid(); #endif error = change_root(real_root_dev,"/initrd"); if (error) printk(KERN_ERR "Change root to /initrd: " "error %d\n",error); } } #endif } static int init(void * unused) { lock_kernel(); do_basic_setup(); /* * 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."); }