reboot(2) System Calls Manual reboot(2) reboot - / Ctrl-Alt-Del (libc -lc) /* Linux 2.1.30 LINUX_REBOOT_* : */ #include /* Definition of LINUX_REBOOT_* constants */ #include /* Definition of SYS_* constants */ #include int syscall(SYS_reboot, int magic, int magic2, int op, void *arg); /* glibc libc ( uclibc dietlibc musl ) RB_* : */ #include /* Definition of RB_* constants */ #include int reboot(int op); reboot() / ( CAD Ctrl-Alt-Delete loadkeys(1)). ( EINVAL) magic LINUX_REBOOT_MAGIC1 ( 0xfee1dead) magic2 LINUX_REBOOT_MAGIC2 ( 0x28121969). 2.1.17 LINUX_REBOOT_MAGIC2A ( 0x05121996) 2.1.97 LINUX_REBOOT_MAGIC2B ( 0x16041998) 2.5.71 LINUX_REBOOT_MAGIC2C ( 0x20112000) magic2. ( .) op : LINUX_REBOOT_CMD_CAD_OFF (RB_DISABLE_CAD, 0). CAD. CAD SIGINT init ( 1) (: ). LINUX_REBOOT_CMD_CAD_ON (RB_ENABLE_CAD, 0x89abcdef). CAD. CAD LINUX_REBOOT_CMD_RESTART. LINUX_REBOOT_CMD_HALT (RB_HALT_SYSTEM, 0xcdef0123; 1.1.76). "System halted." . ROM . sync(2) . LINUX_REBOOT_CMD_KEXEC (RB_KEXEC, 0x45584543, 2.6.13). kexec_load(2). CONFIG_KEXEC. LINUX_REBOOT_CMD_POWER_OFF (RB_POWER_OFF, 0x4321fedc; 2.1.30). "Power down." . sync(2) . LINUX_REBOOT_CMD_RESTART (RB_AUTOBOOT, 0x1234567). "Restarting system." . sync(2) . LINUX_REBOOT_CMD_RESTART2 (0xa1b2c3d4 2.1.30). " '%s'" ( arg) . sync(2) . LINUX_REBOOT_CMD_SW_SUSPEND (RB_SW_SUSPEND, 0xd000fce1; 2.5.18). () . CONFIG_HIBERNATION. reboot(). . i386 (2.1.122) ("reboot=...") BIOS. PID 3.4 reboot() PID op " " : "init" PID pid_namespaces(7). op reboot() : LINUX_REBOOT_CMD_RESTART LINUX_REBOOT_CMD_RESTART2 "init" wait(2) SIGHUP. LINUX_REBOOT_CMD_POWER_OFF LINUX_REBOOT_CMD_HALT "init" wait(2) SIGINT. op reboot() -1 errno EINVAL. op reboot(). op . -1 errno . EFAULT LINUX_REBOOT_CMD_RESTART2. EINVAL op. EPERM reboot() CAP_SYS_BOOT . . systemctl(1), systemd(1), kexec_load(2), sync(2), bootparam(7), capabilities(7), ctrlaltdel(8), halt(8), shutdown(8) 3 . . : . 6.18 8 2026 reboot(2)