Kernel/LibC/Userspace: Add SYS_POWEROFF + cli tool

You can now shutdown/reboot banan-os with the poweroff cli tool.

Reboot doesn't seem to work on qemu.

kernel/include/kernel/Process.h

@@ -111,6 +111,8 @@ namespace Kernel
 
 		BAN::ErrorOr<long> sys_sync(bool should_block);
 
+		BAN::ErrorOr<long> sys_poweroff(int command);
+
 		BAN::ErrorOr<void> mount(BAN::StringView source, BAN::StringView target);
 
 		BAN::ErrorOr<long> sys_read_dir_entries(int fd, DirectoryEntryList* buffer, size_t buffer_size);

kernel/kernel/Process.cpp

@@ -14,8 +14,11 @@
 #include <LibELF/ELF.h>
 #include <LibELF/Values.h>
 
+#include <lai/helpers/pm.h>
+
 #include <fcntl.h>
 #include <stdio.h>
+#include <sys/banan-os.h>
 #include <sys/sysmacros.h>
 #include <sys/wait.h>
 
@@ -773,6 +776,33 @@ namespace Kernel
 		return 0;
 	}
 
+	BAN::ErrorOr<long> Process::sys_poweroff(int command)
+	{
+		if (command != POWEROFF_REBOOT && command != POWEROFF_SHUTDOWN)
+			return BAN::Error::from_errno(EINVAL);
+
+		// FIXME: gracefully kill all processes
+
+		DevFileSystem::get().initiate_sync(true);
+		
+		lai_api_error_t error;
+		switch (command)
+		{
+			case POWEROFF_REBOOT:
+				error = lai_acpi_reset();
+				break;
+			case POWEROFF_SHUTDOWN:
+				error = lai_enter_sleep(5);
+				break;
+			default:
+				ASSERT_NOT_REACHED();
+		}
+		
+		// If we reach here, there was an error
+		dprintln("{}", lai_api_error_to_string(error));
+		return BAN::Error::from_errno(EUNKNOWN);
+	}
+
 	BAN::ErrorOr<long> Process::sys_read_dir_entries(int fd, DirectoryEntryList* list, size_t list_size)
 	{
 		LockGuard _(m_lock);

kernel/kernel/Syscall.cpp

@@ -196,6 +196,9 @@ namespace Kernel
 		case SYS_TTY_CTRL:
 			ret = Process::current().sys_tty_ctrl((int)arg1, (int)arg2, (int)arg3);
 			break;
+		case SYS_POWEROFF:
+			ret = Process::current().sys_poweroff((int)arg1);
+			break;
 		default:
 			dwarnln("Unknown syscall {}", syscall);
 			break;

libc/include/sys/banan-os.h

@@ -11,8 +11,8 @@ __BEGIN_DECLS
 #define TTY_FLAG_ENABLE_OUTPUT	1
 #define TTY_FLAG_ENABLE_INPUT	2
 
-#define POWER_SHUTDOWN 0
-#define POWER_REBOOT 1
+#define POWEROFF_SHUTDOWN 0
+#define POWEROFF_REBOOT 1
 
 /*
 fildes:		refers to valid tty device
@@ -22,6 +22,7 @@ flags:		bitwise or of TTY_FLAG_* definitions
 return value: 0 on success, -1 on failure and errno set to the error
 */
 int tty_ctrl(int fildes, int command, int flags);
+int poweroff(int command);
 
 __END_DECLS
 

libc/include/sys/syscall.h

@@ -54,6 +54,7 @@ __BEGIN_DECLS
 #define SYS_MMAP 51
 #define SYS_MUNMAP 52
 #define SYS_TTY_CTRL 53
+#define SYS_POWEROFF 54
 
 __END_DECLS
 

libc/sys/banan-os.cpp

@@ -6,3 +6,8 @@ int tty_ctrl(int fildes, int command, int flags)
 {
 	return syscall(SYS_TTY_CTRL, fildes, command, flags);
 }
+
+int poweroff(int command)
+{
+	return syscall(SYS_POWEROFF, command);
+}

userspace/CMakeLists.txt

@@ -9,6 +9,7 @@ set(USERSPACE_PROJECTS
 	id
 	init
 	ls
+	poweroff
 	Shell
 	snake
 	stat

userspace/poweroff/CMakeLists.txt

@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.26)
+
+project(poweroff CXX)
+
+set(SOURCES
+	main.cpp
+)
+
+add_executable(poweroff ${SOURCES})
+target_compile_options(poweroff PUBLIC -O2 -g)
+target_link_libraries(poweroff PUBLIC libc)
+
+add_custom_target(poweroff-install
+	COMMAND sudo cp ${CMAKE_CURRENT_BINARY_DIR}/poweroff ${BANAN_BIN}/
+	DEPENDS poweroff
+	USES_TERMINAL
+)

userspace/poweroff/main.cpp

@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/banan-os.h>
+
+void usage(int ret, char* arg0)
+{
+	FILE* fout = (ret == 0) ? stdout : stderr;
+	fprintf(fout, "usage: %s [OPTIONS]...\n");
+	fprintf(fout, "  -s, --shutdown  Shutdown the system (default)\n");
+	fprintf(fout, "  -r, --reboot    Reboot the system\n");
+	fprintf(fout, "  -h, --help      Show this message\n");
+	exit(ret);
+}
+
+int main(int argc, char** argv)
+{
+	int operation = POWEROFF_SHUTDOWN;
+	for (int i = 1; i < argc; i++)
+	{
+		if (strcmp(argv[i], "-s") == 0 || strcmp(argv[i], "--shutdown") == 0)
+			operation = POWEROFF_SHUTDOWN;
+		else if (strcmp(argv[i], "-r") == 0 || strcmp(argv[i], "--reboot") == 0)
+			operation = POWEROFF_REBOOT;
+		else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0)
+			usage(0, argv[0]);
+		else
+			usage(1, argv[0]);
+	}
+
+	if (poweroff(operation) == -1)
+	{
+		perror("poweroff");
+		return 1;
+	}
+
+	return 0;
+}