feat(syscall): implemented the reboot syscall with shutdown and reboot commands

kernel/arch/aarch64/syscall/linux_syscalls.h

@@ -47,6 +47,7 @@ constexpr uint64_t RT_SIGACTION     = 134;
 constexpr uint64_t RT_SIGPROCMASK   = 135;
 constexpr uint64_t RT_SIGPENDING    = 136;
 constexpr uint64_t RT_SIGRETURN     = 139;
+constexpr uint64_t REBOOT           = 142;
 constexpr uint64_t SETPGID          = 154;
 constexpr uint64_t GETPGID          = 155;
 constexpr uint64_t UNAME            = 160;

kernel/arch/x86_64/syscall/linux_syscalls.h

@@ -70,6 +70,7 @@ constexpr uint64_t SETPGID          = 109;
 constexpr uint64_t GETPGID          = 121;
 constexpr uint64_t RT_SIGPENDING    = 127;
 constexpr uint64_t ARCH_PRCTL       = 158;
+constexpr uint64_t REBOOT           = 169;
 constexpr uint64_t GETTID           = 186;
 constexpr uint64_t TKILL            = 200;
 constexpr uint64_t FUTEX            = 202;

kernel/syscall/handlers/sys_power.cpp

@@ -0,0 +1,49 @@
+#include "syscall/handlers/sys_power.h"
+
+#include "power/power.h"
+#include "hw/cpu.h"
+#include "common/logging.h"
+
+// Linux reboot(2) magic values, required so a stray syscall with a
+// garbage number cannot take the machine down by accident.
+constexpr uint32_t REBOOT_MAGIC1  = 0xFEE1DEAD;
+constexpr uint32_t REBOOT_MAGIC2  = 672274793;
+constexpr uint32_t REBOOT_MAGIC2A = 85072278;
+constexpr uint32_t REBOOT_MAGIC2B = 369367448;
+constexpr uint32_t REBOOT_MAGIC2C = 537993216;
+
+// Linux reboot(2) commands
+constexpr uint32_t REBOOT_CMD_RESTART   = 0x01234567;
+constexpr uint32_t REBOOT_CMD_HALT      = 0xCDEF0123;
+constexpr uint32_t REBOOT_CMD_POWER_OFF = 0x4321FEDC;
+
+DEFINE_SYSCALL3(reboot, magic1, magic2, cmd) {
+    if (static_cast<uint32_t>(magic1) != REBOOT_MAGIC1) {
+        return syscall::EINVAL;
+    }
+
+    uint32_t m2 = static_cast<uint32_t>(magic2);
+    if (m2 != REBOOT_MAGIC2 && m2 != REBOOT_MAGIC2A &&
+        m2 != REBOOT_MAGIC2B && m2 != REBOOT_MAGIC2C) {
+        return syscall::EINVAL;
+    }
+
+    switch (static_cast<uint32_t>(cmd)) {
+    case REBOOT_CMD_RESTART:
+        log::info("power: restarting system");
+        power::reboot();
+        return syscall::EOPNOTSUPP;
+    case REBOOT_CMD_POWER_OFF:
+        log::info("power: powering off");
+        power::shutdown();
+        return syscall::EOPNOTSUPP;
+    case REBOOT_CMD_HALT:
+        log::info("power: system halted");
+        cpu::irq_disable();
+        while (true) {
+            cpu::halt();
+        }
+    default:
+        return syscall::EINVAL;
+    }
+}

kernel/syscall/handlers/sys_power.h

@@ -0,0 +1,8 @@
+#ifndef STELLUX_SYSCALL_HANDLERS_SYS_POWER_H
+#define STELLUX_SYSCALL_HANDLERS_SYS_POWER_H
+
+#include "syscall/syscall_table.h"
+
+DECLARE_SYSCALL(reboot);
+
+#endif // STELLUX_SYSCALL_HANDLERS_SYS_POWER_H

kernel/syscall/syscall_table.cpp

@@ -21,6 +21,7 @@
 #include "syscall/handlers/sys_pipe.h"
 #include "syscall/handlers/sys_uname.h"
 #include "syscall/handlers/sys_futex.h"
+#include "syscall/handlers/sys_power.h"
 
 namespace syscall {
 
@@ -85,6 +86,7 @@ __PRIVILEGED_CODE void init_syscall_table() {
     REGISTER_SYSCALL(linux_nr::CLOCK_GETRES,    clock_getres);
     REGISTER_SYSCALL(linux_nr::GETTIMEOFDAY,    gettimeofday);
     REGISTER_SYSCALL(linux_nr::UNAME,           uname);
+    REGISTER_SYSCALL(linux_nr::REBOOT,          reboot);
 
     REGISTER_SYSCALL(linux_nr::SOCKET,      socket);
     REGISTER_SYSCALL(linux_nr::SOCKETPAIR,  socketpair);

userland/apps/Makefile

@@ -5,7 +5,8 @@
 APP_DIRS := init hello shell ls cat rm stat touch sleep true false clear ptytest date \
 			clockbench stlxdm stlxterm doom ping ifconfig nslookup arp udpecho tcpecho \
 			fetch polltest sigtest dropbear blackjack wordle hangman snake tetris \
-			grep wc head threadtest pthreadtest uname kill cxxtest synctest python vim stlxtop
+			grep wc head threadtest pthreadtest uname kill cxxtest synctest python vim stlxtop \
+			reboot shutdown
 APP_COUNT := $(words $(APP_DIRS))
 
 all:

userland/apps/reboot/Makefile

@@ -0,0 +1,2 @@
+APP_NAME := reboot
+include ../../mk/app.mk

userland/apps/reboot/src/reboot.c

@@ -0,0 +1,13 @@
+#include <stdio.h>
+#include <sys/reboot.h>
+
+int main(void) {
+    printf("Restarting system...\n");
+    fflush(stdout);
+
+    reboot(RB_AUTOBOOT);
+
+    // Only reachable when the kernel could not restart the machine
+    perror("reboot");
+    return 1;
+}

userland/apps/shutdown/Makefile

@@ -0,0 +1,2 @@
+APP_NAME := shutdown
+include ../../mk/app.mk

userland/apps/shutdown/src/shutdown.c

@@ -0,0 +1,18 @@
+#include <stdio.h>
+#include <sys/reboot.h>
+
+int main(void) {
+    printf("Powering off...\n");
+    fflush(stdout);
+
+    reboot(RB_POWER_OFF);
+
+    // Only reachable when the platform could not power off, so stop
+    // the machine in a state that is safe to switch off by hand.
+    printf("Power off unsupported, halting instead.\n");
+    fflush(stdout);
+    reboot(RB_HALT_SYSTEM);
+
+    perror("shutdown");
+    return 1;
+}