From 9cff7866d58bfd48cad3f32882b957499c06a649 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Sun, 19 May 2024 22:37:00 -0400
Subject: kernel: Add reboot() and reboot syscall

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 builddeps/sysexports           |  1 +
 lib/libc/src/sys/reboot.c      | 45 +++++++++++++++++++++++++++++++++++++
 sys/arch/amd64/amd64/machdep.c |  9 ++++++++
 sys/include/sys/machdep.h      |  1 +
 sys/include/sys/reboot.h       | 45 +++++++++++++++++++++++++++++++++++++
 sys/include/sys/syscall.h      |  1 +
 sys/kern/kern_reboot.c         | 51 ++++++++++++++++++++++++++++++++++++++++++
 sys/kern/kern_syscall.c        |  4 +++-
 8 files changed, 156 insertions(+), 1 deletion(-)
 create mode 100644 lib/libc/src/sys/reboot.c
 create mode 100644 sys/include/sys/reboot.h
 create mode 100644 sys/kern/kern_reboot.c

diff --git a/builddeps/sysexports b/builddeps/sysexports
index 7069c57..66a82a6 100644
--- a/builddeps/sysexports
+++ b/builddeps/sysexports
@@ -8,5 +8,6 @@ sys_headers=$(cat <<END
     signal.h
     termios.h
     tty.h
+    reboot.h
 END
 )
diff --git a/lib/libc/src/sys/reboot.c b/lib/libc/src/sys/reboot.c
new file mode 100644
index 0000000..8fd2909
--- /dev/null
+++ b/lib/libc/src/sys/reboot.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/syscall.h>
+#include <sys/reboot.h>
+
+/*
+ * Reboots the system.
+ *
+ * @type: Reboot method.
+ *
+ * On success, this function does not return.
+ * On failure, a value < 0 is returned.
+ */
+int
+reboot(int type)
+{
+    return syscall(SYS_reboot);
+}
diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c
index 6a24232..34bea11 100644
--- a/sys/arch/amd64/amd64/machdep.c
+++ b/sys/arch/amd64/amd64/machdep.c
@@ -330,6 +330,15 @@ processor_switch_to(struct proc *old_td, struct proc *new_td)
     amd64_fxrstor(new_pcb->fpu_state);
 }
 
+void
+cpu_reset(void)
+{
+    for (;;) {
+        /* Pulse the reset line */
+        outb(0x64, 0xFE);
+    }
+}
+
 void
 processor_init(void)
 {
diff --git a/sys/include/sys/machdep.h b/sys/include/sys/machdep.h
index 31385ce..0ecb83e 100644
--- a/sys/include/sys/machdep.h
+++ b/sys/include/sys/machdep.h
@@ -50,6 +50,7 @@ __weak void chips_init(void);
 __weak void pre_init(void);
 __weak void serial_dbgch(char c);
 __weak void cpu_halt_others(void);
+__weak void cpu_reset(void);
 
 #endif  /* defined(_KERNEL) */
 #endif  /* !_SYS_MACHDEP_H_ */
diff --git a/sys/include/sys/reboot.h b/sys/include/sys/reboot.h
new file mode 100644
index 0000000..e09bd4f
--- /dev/null
+++ b/sys/include/sys/reboot.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _SYS_REBOOT_H_
+#define _SYS_REBOOT_H_
+
+#if defined(_KERNEL)
+#include <sys/syscall.h>
+#endif
+
+#define REBOOT_DEFAULT 0x0000
+
+int reboot(int type);
+
+#if defined(_KERNEL)
+uint64_t sys_reboot(struct syscall_args *args);
+#endif  /* defined(_KERNEL) */
+
+#endif  /* !_SYS_REBOOT_H_ */
diff --git a/sys/include/sys/syscall.h b/sys/include/sys/syscall.h
index 6a102aa..4ef3666 100644
--- a/sys/include/sys/syscall.h
+++ b/sys/include/sys/syscall.h
@@ -48,6 +48,7 @@ enum {
     SYS_ioctl,
     SYS_execv,
     SYS_mount,
+    SYS_reboot,
     __MAX_SYSCALLS
 };
 
diff --git a/sys/kern/kern_reboot.c b/sys/kern/kern_reboot.c
new file mode 100644
index 0000000..8f7c400
--- /dev/null
+++ b/sys/kern/kern_reboot.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/reboot.h>
+#include <sys/panic.h>
+#include <sys/cdefs.h>
+#include <sys/machdep.h>
+
+int
+reboot(int type)
+{
+    __TRY_CALL(cpu_reset);
+
+    /* Should be unreachable if the reboot works */
+    return -1;
+}
+
+/*
+ * Arg0: Type
+ */
+uint64_t
+sys_reboot(struct syscall_args *args)
+{
+    return reboot(args->arg0);
+}
diff --git a/sys/kern/kern_syscall.c b/sys/kern/kern_syscall.c
index 9faa5af..35185ea 100644
--- a/sys/kern/kern_syscall.c
+++ b/sys/kern/kern_syscall.c
@@ -34,6 +34,7 @@
 #include <sys/filedesc.h>
 #include <sys/system.h>
 #include <sys/exec.h>
+#include <sys/reboot.h>
 #include <sys/vfs.h>
 #include <vm/map.h>
 
@@ -48,5 +49,6 @@ uint64_t(*g_syscall_table[__MAX_SYSCALLS])(struct syscall_args *args) = {
     sys_munmap,
     sys_ioctl,
     sys_execv,
-    sys_mount
+    sys_mount,
+    sys_reboot
 };
-- 
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