/* * 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 DEBUG /* Enable initcall_debug */ #include <linux/types.h>#include <linux/module.h>#include <linux/proc_fs.h>#include <linux/kernel.h>#include <linux/syscalls.h>#include <linux/stackprotector.h>#include <linux/string.h>#include <linux/ctype.h>#include <linux/delay.h>#include <linux/ioport.h>#include <linux/init.h>#include <linux/initrd.h>#include <linux/bootmem.h>#include <linux/acpi.h>#include <linux/tty.h>#include <linux/percpu.h>#include <linux/kmod.h>#include <linux/vmalloc.h>#include <linux/kernel_stat.h>#include <linux/start_kernel.h>#include <linux/security.h>#include <linux/smp.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/cgroup.h>#include <linux/efi.h>#include <linux/tick.h>#include <linux/interrupt.h>#include <linux/taskstats_kern.h>#include <linux/delayacct.h>#include <linux/unistd.h>#include <linux/rmap.h>#include <linux/mempolicy.h>#include <linux/key.h>#include <linux/buffer_head.h>#include <linux/page_ext.h>#include <linux/debug_locks.h>#include <linux/debugobjects.h>#include <linux/lockdep.h>#include <linux/kmemleak.h>#include <linux/pid_namespace.h>#include <linux/device.h>#include <linux/kthread.h>#include <linux/sched.h>#include <linux/signal.h>#include <linux/idr.h>#include <linux/kgdb.h>#include <linux/ftrace.h>#include <linux/async.h>#include <linux/kmemcheck.h>#include <linux/sfi.h>#include <linux/shmem_fs.h>#include <linux/slab.h>#include <linux/perf_event.h>#include <linux/file.h>#include <linux/ptrace.h>#include <linux/blkdev.h>#include <linux/elevator.h>#include <linux/sched_clock.h>#include <linux/context_tracking.h>#include <linux/random.h>#include <linux/list.h>#include <linux/integrity.h>#include <linux/proc_ns.h>#include <linux/io.h> #include <asm/io.h>#include <asm/bugs.h>#include <asm/setup.h>#include <asm/sections.h>#include <asm/cacheflush.h> static int kernel_init(void *); extern void init_IRQ(void);extern void fork_init(void);extern void radix_tree_init(void);#ifndef CONFIG_DEBUG_RODATAstatic inline void mark_rodata_ro(void) { }#endif /* * Debug helper: via this flag we know that we are in 'early bootup code' * where only the boot processor is running with IRQ disabled. This means * two things - IRQ must not be enabled before the flag is cleared and some * operations which are not allowed with IRQ disabled are allowed while the * flag is set. */bool early_boot_irqs_disabled __read_mostly; enum system_states system_state __read_mostly;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 (*__initdata late_time_init)(void); /* Untouched command line saved by arch-specific code. */char __initdata boot_command_line[COMMAND_LINE_SIZE];/* Untouched saved command line (eg. for /proc) */char *saved_command_line;/* Command line for parameter parsing */static char *static_command_line;/* Command line for per-initcall parameter parsing */static char *initcall_command_line; static char *execute_command;static char *ramdisk_execute_command; /* * Used to generate warnings if static_key manipulation functions are used * before jump_label_init is called. */bool static_key_initialized __read_mostly;EXPORT_SYMBOL_GPL(static_key_initialized); /* * If set, this is an indication to the drivers that reset the underlying * device before going ahead with the initialization otherwise driver might * rely on the BIOS and skip the reset operation. * * This is useful if kernel is booting in an unreliable environment. * For ex. kdump situation where previous kernel has crashed, BIOS has been * skipped and devices will be in unknown state. */unsigned int reset_devices;EXPORT_SYMBOL(reset_devices); static int __init set_reset_devices(char *str){ reset_devices = 1; return 1;} __setup("reset_devices", set_reset_devices); static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };static const char *panic_later, *panic_param; extern const struct obs_kernel_param __setup_start[], __setup_end[]; static int __init obsolete_checksetup(char *line){ const struct obs_kernel_param *p; int had_early_param = 0; p = __setup_start; do { int n = strlen(p->str); if (parameqn(line, p->str, n)) { if (p->early) { /* Already done in parse_early_param? * (Needs exact match on param part). * Keep iterating, as we can have early * params and __setups of same names 8( */ if (line[n] == '\0' || line[n] == '=') had_early_param = 1; } else if (!p->setup_func) { pr_warn("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 had_early_param;} /* * 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){ console_loglevel = CONSOLE_LOGLEVEL_DEBUG; return 0;} static int __init quiet_kernel(char *str){ console_loglevel = CONSOLE_LOGLEVEL_QUIET; return 0;} early_param("debug", debug_kernel);early_param("quiet", quiet_kernel); static int __init loglevel(char *str){ int newlevel; /* * Only update loglevel value when a correct setting was passed, * to prevent blind crashes (when loglevel being set to 0) that * are quite hard to debug */ if (get_option(&str, &newlevel)) { console_loglevel = newlevel; return 0; } return -EINVAL;} early_param("loglevel", loglevel); /* Change NUL term back to "=", to make "param" the whole string. */static int __init repair_env_string(char *param, char *val, const char *unused, void *arg){ 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(); } return 0;} /* Anything after -- gets handed straight to init. */static int __init set_init_arg(char *param, char *val, const char *unused, void *arg){ unsigned int i; if (panic_later) return 0; repair_env_string(param, val, unused, NULL); for (i = 0; argv_init[i]; i++) { if (i == MAX_INIT_ARGS) { panic_later = "init"; panic_param = param; return 0; } } argv_init[i] = param; return 0;} /* * Unknown boot options get handed to init, unless they look like * unused parameters (modprobe will find them in /proc/cmdline). */static int __init unknown_bootoption(char *param, char *val, const char *unused, void *arg){ repair_env_string(param, val, unused, NULL); /* Handle obsolete-style parameters */ if (obsolete_checksetup(param)) return 0; /* Unused module parameter. */ if (strchr(param, '.') && (!val || strchr(param, '.') < val)) 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 = "env"; 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 = "init"; 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); static int __init rdinit_setup(char *str){ unsigned int i; ramdisk_execute_command = str; /* See "auto" comment in init_setup */ for (i = 1; i < MAX_INIT_ARGS; i++) argv_init[i] = NULL; return 1;}__setup("rdinit=", rdinit_setup); #ifndef CONFIG_SMPstatic const unsigned int setup_max_cpus = NR_CPUS;static inline void setup_nr_cpu_ids(void) { }static inline void smp_prepare_cpus(unsigned int maxcpus) { }#endif /* * We need to store the untouched command line for future reference. * We also need to store the touched command line since the parameter * parsing is performed in place, and we should allow a component to * store reference of name/value for future reference. */static void __init setup_command_line(char *command_line){ saved_command_line = memblock_virt_alloc(strlen(boot_command_line) + 1, 0); initcall_command_line = memblock_virt_alloc(strlen(boot_command_line) + 1, 0); static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0); strcpy(saved_command_line, boot_command_line); strcpy(static_command_line, command_line);} /* * 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 __initdata DECLARE_COMPLETION(kthreadd_done); static noinline void __init_refok rest_init(void){ int pid; rcu_scheduler_starting(); smpboot_thread_init(); /* * We need to spawn init first so that it obtains pid 1, however * the init task will end up wanting to create kthreads, which, if * we schedule it before we create kthreadd, will OOPS. */ kernel_thread(kernel_init, NULL, CLONE_FS); numa_default_policy(); pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); rcu_read_lock(); kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); rcu_read_unlock(); complete(&kthreadd_done); /* * The boot idle thread must execute schedule() * at least once to get things moving: */ init_idle_bootup_task(current); schedule_preempt_disabled(); /* Call into cpu_idle with preempt disabled */ cpu_startup_entry(CPUHP_ONLINE);} /* Check for early params. */static int __init do_early_param(char *param, char *val, const char *unused, void *arg){ const struct obs_kernel_param *p; for (p = __setup_start; p < __setup_end; p++) { if ((p->early && parameq(param, p->str)) || (strcmp(param, "console") == 0 && strcmp(p->str, "earlycon") == 0) ) { if (p->setup_func(val) != 0) pr_warn("Malformed early option '%s'\n", param); } } /* We accept everything at this stage. */ return 0;} void __init parse_early_options(char *cmdline){ parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, do_early_param);} /* Arch code calls this early on, or if not, just before other parsing. */void __init parse_early_param(void){ static int done __initdata; static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; if (done) return; /* All fall through to do_early_param. */ strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); parse_early_options(tmp_cmdline); done = 1;} /* * Activate the first processor. */ static void __init boot_cpu_init(void){ int cpu = smp_processor_id(); /* Mark the boot cpu "present", "online" etc for SMP and UP case */ set_cpu_online(cpu, true); set_cpu_active(cpu, true); set_cpu_present(cpu, true); set_cpu_possible(cpu, true);} void __init __weak smp_setup_processor_id(void){} # if THREAD_SIZE >= PAGE_SIZEvoid __init __weak thread_info_cache_init(void){}#endif /* * Set up kernel memory allocators */static void __init mm_init(void){ /* * page_ext requires contiguous pages, * bigger than MAX_ORDER unless SPARSEMEM. */ page_ext_init_flatmem(); mem_init(); kmem_cache_init(); percpu_init_late(); pgtable_init(); vmalloc_init(); ioremap_huge_init();} asmlinkage __visible void __init start_kernel(void){ char *command_line; char *after_dashes;Lines 1–500 of 1040. 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/* * 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 DEBUG /* Enable initcall_debug */ #include <linux/types.h> #include <linux/module.h> #include <linux/proc_fs.h> #include <linux/kernel.h> #include <linux/syscalls.h> #include <linux/stackprotector.h> #include <linux/string.h> #include <linux/ctype.h> #include <linux/delay.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/initrd.h> #include <linux/bootmem.h> #include <linux/acpi.h> #include <linux/tty.h> #include <linux/percpu.h> #include <linux/kmod.h> #include <linux/vmalloc.h> #include <linux/kernel_stat.h> #include <linux/start_kernel.h> #include <linux/security.h> #include <linux/smp.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/cgroup.h> #include <linux/efi.h> #include <linux/tick.h> #include <linux/interrupt.h> #include <linux/taskstats_kern.h> #include <linux/delayacct.h> #include <linux/unistd.h> #include <linux/rmap.h> #include <linux/mempolicy.h> #include <linux/key.h> #include <linux/buffer_head.h> #include <linux/page_ext.h> #include <linux/debug_locks.h> #include <linux/debugobjects.h> #include <linux/lockdep.h> #include <linux/kmemleak.h> #include <linux/pid_namespace.h> #include <linux/device.h> #include <linux/kthread.h> #include <linux/sched.h> #include <linux/signal.h> #include <linux/idr.h> #include <linux/kgdb.h> #include <linux/ftrace.h> #include <linux/async.h> #include <linux/kmemcheck.h> #include <linux/sfi.h> #include <linux/shmem_fs.h> #include <linux/slab.h> #include <linux/perf_event.h> #include <linux/file.h> #include <linux/ptrace.h> #include <linux/blkdev.h> #include <linux/elevator.h> #include <linux/sched_clock.h> #include <linux/context_tracking.h> #include <linux/random.h> #include <linux/list.h> #include <linux/integrity.h> #include <linux/proc_ns.h> #include <linux/io.h> #include <asm/io.h> #include <asm/bugs.h> #include <asm/setup.h> #include <asm/sections.h> #include <asm/cacheflush.h> static int kernel_init(void *); extern void init_IRQ(void); extern void fork_init(void); extern void radix_tree_init(void); #ifndef CONFIG_DEBUG_RODATA static inline void mark_rodata_ro(void) { } #endif /* * Debug helper: via this flag we know that we are in 'early bootup code' * where only the boot processor is running with IRQ disabled. This means * two things - IRQ must not be enabled before the flag is cleared and some * operations which are not allowed with IRQ disabled are allowed while the * flag is set. */ bool early_boot_irqs_disabled __read_mostly; enum system_states system_state __read_mostly; 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 (*__initdata late_time_init)(void); /* Untouched command line saved by arch-specific code. */ char __initdata boot_command_line[COMMAND_LINE_SIZE]; /* Untouched saved command line (eg. for /proc) */ char *saved_command_line; /* Command line for parameter parsing */ static char *static_command_line; /* Command line for per-initcall parameter parsing */ static char *initcall_command_line; static char *execute_command; static char *ramdisk_execute_command; /* * Used to generate warnings if static_key manipulation functions are used * before jump_label_init is called. */ bool static_key_initialized __read_mostly; EXPORT_SYMBOL_GPL(static_key_initialized); /* * If set, this is an indication to the drivers that reset the underlying * device before going ahead with the initialization otherwise driver might * rely on the BIOS and skip the reset operation. * * This is useful if kernel is booting in an unreliable environment. * For ex. kdump situation where previous kernel has crashed, BIOS has been * skipped and devices will be in unknown state. */ unsigned int reset_devices; EXPORT_SYMBOL(reset_devices); static int __init set_reset_devices(char *str) { reset_devices = 1; return 1; } __setup("reset_devices", set_reset_devices); static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; static const char *panic_later, *panic_param; extern const struct obs_kernel_param __setup_start[], __setup_end[]; static int __init obsolete_checksetup(char *line) { const struct obs_kernel_param *p; int had_early_param = 0; p = __setup_start; do { int n = strlen(p->str); if (parameqn(line, p->str, n)) { if (p->early) { /* Already done in parse_early_param? * (Needs exact match on param part). * Keep iterating, as we can have early * params and __setups of same names 8( */ if (line[n] == '\0' || line[n] == '=') had_early_param = 1; } else if (!p->setup_func) { pr_warn("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 had_early_param; } /* * 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) { console_loglevel = CONSOLE_LOGLEVEL_DEBUG; return 0; } static int __init quiet_kernel(char *str) { console_loglevel = CONSOLE_LOGLEVEL_QUIET; return 0; } early_param("debug", debug_kernel); early_param("quiet", quiet_kernel); static int __init loglevel(char *str) { int newlevel; /* * Only update loglevel value when a correct setting was passed, * to prevent blind crashes (when loglevel being set to 0) that * are quite hard to debug */ if (get_option(&str, &newlevel)) { console_loglevel = newlevel; return 0; } return -EINVAL; } early_param("loglevel", loglevel); /* Change NUL term back to "=", to make "param" the whole string. */ static int __init repair_env_string(char *param, char *val, const char *unused, void *arg) { 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(); } return 0; } /* Anything after -- gets handed straight to init. */ static int __init set_init_arg(char *param, char *val, const char *unused, void *arg) { unsigned int i; if (panic_later) return 0; repair_env_string(param, val, unused, NULL); for (i = 0; argv_init[i]; i++) { if (i == MAX_INIT_ARGS) { panic_later = "init"; panic_param = param; return 0; } } argv_init[i] = param; return 0; } /* * Unknown boot options get handed to init, unless they look like * unused parameters (modprobe will find them in /proc/cmdline). */ static int __init unknown_bootoption(char *param, char *val, const char *unused, void *arg) { repair_env_string(param, val, unused, NULL); /* Handle obsolete-style parameters */ if (obsolete_checksetup(param)) return 0; /* Unused module parameter. */ if (strchr(param, '.') && (!val || strchr(param, '.') < val)) 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 = "env"; 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 = "init"; 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); static int __init rdinit_setup(char *str) { unsigned int i; ramdisk_execute_command = str; /* See "auto" comment in init_setup */ for (i = 1; i < MAX_INIT_ARGS; i++) argv_init[i] = NULL; return 1; } __setup("rdinit=", rdinit_setup); #ifndef CONFIG_SMP static const unsigned int setup_max_cpus = NR_CPUS; static inline void setup_nr_cpu_ids(void) { } static inline void smp_prepare_cpus(unsigned int maxcpus) { } #endif /* * We need to store the untouched command line for future reference. * We also need to store the touched command line since the parameter * parsing is performed in place, and we should allow a component to * store reference of name/value for future reference. */ static void __init setup_command_line(char *command_line) { saved_command_line = memblock_virt_alloc(strlen(boot_command_line) + 1, 0); initcall_command_line = memblock_virt_alloc(strlen(boot_command_line) + 1, 0); static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0); strcpy(saved_command_line, boot_command_line); strcpy(static_command_line, command_line); } /* * 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 __initdata DECLARE_COMPLETION(kthreadd_done); static noinline void __init_refok rest_init(void) { int pid; rcu_scheduler_starting(); smpboot_thread_init(); /* * We need to spawn init first so that it obtains pid 1, however * the init task will end up wanting to create kthreads, which, if * we schedule it before we create kthreadd, will OOPS. */ kernel_thread(kernel_init, NULL, CLONE_FS); numa_default_policy(); pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); rcu_read_lock(); kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); rcu_read_unlock(); complete(&kthreadd_done); /* * The boot idle thread must execute schedule() * at least once to get things moving: */ init_idle_bootup_task(current); schedule_preempt_disabled(); /* Call into cpu_idle with preempt disabled */ cpu_startup_entry(CPUHP_ONLINE); } /* Check for early params. */ static int __init do_early_param(char *param, char *val, const char *unused, void *arg) { const struct obs_kernel_param *p; for (p = __setup_start; p < __setup_end; p++) { if ((p->early && parameq(param, p->str)) || (strcmp(param, "console") == 0 && strcmp(p->str, "earlycon") == 0) ) { if (p->setup_func(val) != 0) pr_warn("Malformed early option '%s'\n", param); } } /* We accept everything at this stage. */ return 0; } void __init parse_early_options(char *cmdline) { parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, do_early_param); } /* Arch code calls this early on, or if not, just before other parsing. */ void __init parse_early_param(void) { static int done __initdata; static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; if (done) return; /* All fall through to do_early_param. */ strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); parse_early_options(tmp_cmdline); done = 1; } /* * Activate the first processor. */ static void __init boot_cpu_init(void) { int cpu = smp_processor_id(); /* Mark the boot cpu "present", "online" etc for SMP and UP case */ set_cpu_online(cpu, true); set_cpu_active(cpu, true); set_cpu_present(cpu, true); set_cpu_possible(cpu, true); } void __init __weak smp_setup_processor_id(void) { } # if THREAD_SIZE >= PAGE_SIZE void __init __weak thread_info_cache_init(void) { } #endif /* * Set up kernel memory allocators */ static void __init mm_init(void) { /* * page_ext requires contiguous pages, * bigger than MAX_ORDER unless SPARSEMEM. */ page_ext_init_flatmem(); mem_init(); kmem_cache_init(); percpu_init_late(); pgtable_init(); vmalloc_init(); ioremap_huge_init(); } asmlinkage __visible void __init start_kernel(void) { char *command_line; char *after_dashes;