kern/amd64: Add panic function + MU helpers

This commit introduces a panic function as well as a panic machine
unifier layer for MD specifics that help bring the system to a halt.

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/sys/arch/amd64/os/os_panic.c b/sys/arch/amd64/os/os_panic.c
new file mode 100644
index 0000000..cd55aac
--- /dev/null
+++ b/sys/arch/amd64/os/os_panic.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2025 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 PURPKERNE
+ * 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; LKERNS 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
+ * PKERNSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <mu/panic.h>
+
+void
+mu_panic_preamble(void)
+{
+    static uint64_t sync = 0;
+
+    asm volatile(
+        "cli\n\t"
+        "mov $1, %%rax\n\t"
+        "1:\n\t"
+        "   pause\n\t"
+        "   xchg %0, %%rax\n\t"
+        "   or %%rax, %%rax\n\t"
+        "   jnz 1b\n"
+        :
+        : "m" (sync)
+        : "memory"
+    );
+}
+
+void
+mu_panic_hcf(void)
+{
+    for (;;) {
+        asm volatile("cli; hlt");
+    }
+}