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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /init/main.c
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Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'init/main.c')
-rw-r--r--init/main.c713
1 files changed, 713 insertions, 0 deletions
diff --git a/init/main.c b/init/main.c
new file mode 100644
index 00000000000..40bf367ffdf
--- /dev/null
+++ b/init/main.c
@@ -0,0 +1,713 @@
+/*
+ * 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/types.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/kernel.h>
+#include <linux/syscalls.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/initrd.h>
+#include <linux/hdreg.h>
+#include <linux/bootmem.h>
+#include <linux/tty.h>
+#include <linux/gfp.h>
+#include <linux/percpu.h>
+#include <linux/kmod.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/kallsyms.h>
+#include <linux/writeback.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/efi.h>
+#include <linux/unistd.h>
+#include <linux/rmap.h>
+#include <linux/mempolicy.h>
+#include <linux/key.h>
+
+#include <asm/io.h>
+#include <asm/bugs.h>
+#include <asm/setup.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
+
+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 prio_tree_init(void);
+extern void radix_tree_init(void);
+extern void free_initmem(void);
+extern void populate_rootfs(void);
+extern void driver_init(void);
+extern void prepare_namespace(void);
+#ifdef CONFIG_ACPI
+extern void acpi_early_init(void);
+#else
+static inline void acpi_early_init(void) { }
+#endif
+
+#ifdef CONFIG_TC
+extern void tc_init(void);
+#endif
+
+enum system_states system_state;
+EXPORT_SYMBOL(system_state);
+
+/*
+ * Boot command-line arguments
+ */
+#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
+#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
+
+extern void time_init(void);
+/* Default late time init is NULL. archs can override this later. */
+void (*late_time_init)(void);
+extern void softirq_init(void);
+
+/* Untouched command line (eg. for /proc) saved by arch-specific code. */
+char saved_command_line[COMMAND_LINE_SIZE];
+
+static 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, };
+static const char *panic_later, *panic_param;
+
+extern struct obs_kernel_param __setup_start[], __setup_end[];
+
+static int __init obsolete_checksetup(char *line)
+{
+ struct obs_kernel_param *p;
+
+ p = __setup_start;
+ do {
+ int n = strlen(p->str);
+ if (!strncmp(line, p->str, n)) {
+ if (p->early) {
+ /* Already done in parse_early_param? (Needs
+ * exact match on param part) */
+ if (line[n] == '\0' || line[n] == '=')
+ return 1;
+ } else if (!p->setup_func) {
+ printk(KERN_WARNING "Parameter %s is obsolete,"
+ " ignored\n", p->str);
+ return 1;
+ } else 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);
+
+EXPORT_SYMBOL(loops_per_jiffy);
+
+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);
+
+static int __init loglevel(char *str)
+{
+ get_option(&str, &console_loglevel);
+ return 1;
+}
+
+__setup("loglevel=", loglevel);
+
+/*
+ * 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) {
+ /* param=val or param="val"? */
+ if (val == param+strlen(param)+1)
+ val[-1] = '=';
+ else if (val == param+strlen(param)+2) {
+ val[-2] = '=';
+ memmove(val-1, val, strlen(val)+1);
+ val--;
+ } else
+ BUG();
+ }
+
+ /* 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 (panic_later)
+ return 0;
+
+ if (val) {
+ /* Environment option */
+ unsigned int i;
+ for (i = 0; envp_init[i]; i++) {
+ if (i == MAX_INIT_ENVS) {
+ panic_later = "Too many boot env vars at `%s'";
+ panic_param = param;
+ }
+ if (!strncmp(param, envp_init[i], val - param))
+ break;
+ }
+ envp_init[i] = param;
+ } else {
+ /* Command line option */
+ unsigned int i;
+ for (i = 0; argv_init[i]; i++) {
+ if (i == MAX_INIT_ARGS) {
+ panic_later = "Too many boot init vars at `%s'";
+ panic_param = 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 **);
+
+#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];
+
+EXPORT_SYMBOL(__per_cpu_offset);
+
+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_each_present_cpu(i) {
+ if (num_online_cpus() >= max_cpus)
+ break;
+ if (!cpu_online(i))
+ cpu_up(i);
+ }
+
+ /* Any cleanup work */
+ printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
+ smp_cpus_done(max_cpus);
+#if 0
+ /* Get other processors into their bootup holding patterns. */
+
+ 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.
+ *
+ * gcc-3.4 accidentally inlines this function, so use noinline.
+ */
+
+static void noinline rest_init(void)
+ __releases(kernel_lock)
+{
+ kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
+ numa_default_policy();
+ unlock_kernel();
+ preempt_enable_no_resched();
+ cpu_idle();
+}
+
+/* Check for early params. */
+static int __init do_early_param(char *param, char *val)
+{
+ struct obs_kernel_param *p;
+
+ for (p = __setup_start; p < __setup_end; p++) {
+ if (p->early && strcmp(param, p->str) == 0) {
+ if (p->setup_func(val) != 0)
+ printk(KERN_WARNING
+ "Malformed early option '%s'\n", param);
+ }
+ }
+ /* We accept everything at this stage. */
+ return 0;
+}
+
+/* Arch code calls this early on, or if not, just before other parsing. */
+void __init parse_early_param(void)
+{
+ static __initdata int done = 0;
+ static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
+
+ if (done)
+ return;
+
+ /* All fall through to do_early_param. */
+ strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE);
+ parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
+ done = 1;
+}
+
+/*
+ * Activate the first processor.
+ */
+
+asmlinkage void __init start_kernel(void)
+{
+ char * command_line;
+ extern struct kernel_param __start___param[], __stop___param[];
+/*
+ * Interrupts are still disabled. Do necessary setups, then
+ * enable them
+ */
+ lock_kernel();
+ page_address_init();
+ printk(KERN_NOTICE);
+ printk(linux_banner);
+ setup_arch(&command_line);
+ 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();
+
+ /*
+ * Set up the scheduler prior starting any interrupts (such as the
+ * timer interrupt). Full topology setup happens at smp_init()
+ * time - but meanwhile we still have a functioning scheduler.
+ */
+ sched_init();
+ /*
+ * Disable preemption - early bootup scheduling is extremely
+ * fragile until we cpu_idle() for the first time.
+ */
+ preempt_disable();
+ build_all_zonelists();
+ page_alloc_init();
+ printk(KERN_NOTICE "Kernel command line: %s\n", saved_command_line);
+ parse_early_param();
+ parse_args("Booting kernel", command_line, __start___param,
+ __stop___param - __start___param,
+ &unknown_bootoption);
+ sort_main_extable();
+ trap_init();
+ rcu_init();
+ init_IRQ();
+ pidhash_init();
+ init_timers();
+ 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();
+ if (panic_later)
+ panic(panic_later, panic_param);
+ profile_init();
+ local_irq_enable();
+#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
+ vfs_caches_init_early();
+ mem_init();
+ kmem_cache_init();
+ numa_policy_init();
+ if (late_time_init)
+ late_time_init();
+ calibrate_delay();
+ pidmap_init();
+ pgtable_cache_init();
+ prio_tree_init();
+ anon_vma_init();
+#ifdef CONFIG_X86
+ if (efi_enabled)
+ efi_enter_virtual_mode();
+#endif
+ fork_init(num_physpages);
+ proc_caches_init();
+ buffer_init();
+ unnamed_dev_init();
+ key_init();
+ security_init();
+ vfs_caches_init(num_physpages);
+ radix_tree_init();
+ signals_init();
+ /* rootfs populating might need page-writeback */
+ page_writeback_init();
+#ifdef CONFIG_PROC_FS
+ proc_root_init();
+#endif
+ cpuset_init();
+
+ check_bugs();
+
+ acpi_early_init(); /* before LAPIC and SMP init */
+
+ /* Do the rest non-__init'ed, we're now alive */
+ rest_init();
+}
+
+static 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(KERN_DEBUG "Calling initcall 0x%p", *call);
+ print_fn_descriptor_symbol(": %s()", (unsigned long) *call);
+ printk("\n");
+ }
+
+ (*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(KERN_WARNING "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)
+{
+ /* drivers will send hotplug events */
+ init_workqueues();
+ usermodehelper_init();
+ driver_init();
+
+#ifdef CONFIG_SYSCTL
+ sysctl_init();
+#endif
+
+ /* Networking initialization needs a process context */
+ sock_init();
+
+ 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
+ spawn_ksoftirqd();
+}
+
+static void run_init_process(char *init_filename)
+{
+ argv_init[0] = init_filename;
+ execve(init_filename, argv_init, envp_init);
+}
+
+static inline void fixup_cpu_present_map(void)
+{
+#ifdef CONFIG_SMP
+ int i;
+
+ /*
+ * If arch is not hotplug ready and did not populate
+ * cpu_present_map, just make cpu_present_map same as cpu_possible_map
+ * for other cpu bringup code to function as normal. e.g smp_init() etc.
+ */
+ if (cpus_empty(cpu_present_map)) {
+ for_each_cpu(i) {
+ cpu_set(i, cpu_present_map);
+ }
+ }
+#endif
+}
+
+static int init(void * unused)
+{
+ lock_kernel();
+ /*
+ * init can run on any cpu.
+ */
+ set_cpus_allowed(current, CPU_MASK_ALL);
+ /*
+ * 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();
+
+ fixup_cpu_present_map();
+ smp_init();
+ sched_init_smp();
+
+ cpuset_init_smp();
+
+ /*
+ * Do this before initcalls, because some drivers want to access
+ * firmware files.
+ */
+ populate_rootfs();
+
+ do_basic_setup();
+
+ /*
+ * check if there is an early userspace init. If yes, let it do all
+ * the work
+ */
+ if (sys_access((const char __user *) "/init", 0) == 0)
+ execute_command = "/init";
+ else
+ 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_state = SYSTEM_RUNNING;
+ numa_default_policy();
+
+ if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
+ printk(KERN_WARNING "Warning: unable to open an initial console.\n");
+
+ (void) sys_dup(0);
+ (void) sys_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.");
+}