1 files changed, 87 insertions, 0 deletions
diff --git a/src/sys/acpi/acpi_init.c b/src/sys/acpi/acpi_init.c
new file mode 100644
index 0000000..76c582b
--- /dev/null
+++ b/src/sys/acpi/acpi_init.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * 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 the project 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/bootvars.h>
+#include <sys/panic.h>
+#include <sys/syslog.h>
+#include <acpi/acpi.h>
+#include <acpi/tables.h>
+#include <vm/vm.h>
+
+static size_t root_sdt_len = 0;
+static struct acpi_root_sdt *root_sdt = NULL;
+static uintptr_t rsdp_pa = 0;   /* [physical address] */
+
+size_t
+acpi_get_root_sdt_len(void)
+{
+    return root_sdt_len;
+}
+
+void *
+acpi_get_root_sdt(void)
+{
+    return root_sdt;
+}
+
+/*
+ * ACPI initialization
+ */
+int
+acpi_init(void)
+{
+    struct bootvars bootvars;
+    struct acpi_rsdp *rsdp;
+    int error;
+
+    error = bootvars_read(&bootvars, 0);
+    if (error < 0) {
+        panic("acpi: failed to read bootvars\n");
+    }
+
+    /* Fetch the RSDP */
+    rsdp = bootvars.rsdp;
+    rsdp_pa = VIRT_TO_PHYS(rsdp);
+
+    /* Fetch the root SDT */
+    if (rsdp->revision >= 2) {
+        root_sdt = PHYS_TO_VIRT(rsdp->xsdt_addr);
+        printf("acpi: using XSDT as root SDT\n");
+    } else {
+        root_sdt = PHYS_TO_VIRT(rsdp->rsdt_addr);
+        printf("acpi: using RSDT as root SDT\n");
+    }
+
+    if (acpi_checksum(&root_sdt->hdr) != 0) {
+        panic("root SDT checksum is invalid!\n");
+    }
+
+    root_sdt_len = (root_sdt->hdr.length - sizeof(root_sdt->hdr)) / 4;
+    return 0;
+}